PPC4™
Pressure Controller/Calibrator

Operation and Maintenance Manual

PN 3306047
November 2013
© 2013 Fluke Corporation. All rights reserved. Specifications are subject to change without notice.
All product names are trademarks of their respective companies.

LIMITED WARRANTY AND LIMITATION OF LIABILITY
Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service.
The warranty period is one year and begins on the date of shipment. Parts, product repairs, and services are
warranted for 90 days. This warranty extends only to the original buyer or end-user customer of a Fluke authorized
reseller, and does not apply to fuses, disposable batteries, or to any product which, in Fluke's opinion, has been
misused, altered, neglected, contaminated, or damaged by accident or abnormal conditions of operation or handling.
Fluke warrants that software will operate substantially in accordance with its functional specifications for 90 days andthat it has been properly recorded on non-defective media. Fluke does not warrant that software will be error free oroperate without interruption.
Fluke authorized resellers shall extend this warranty on new and unused products to end-user customers only but
have no authority to extend a greater or different warranty on behalf of Fluke. Warranty support is available only if
product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international price.
Fluke reserves the right to invoice Buyer for importation costs of repair/replacement parts when product purchased in
one country is submitted for repair in another country.
Fluke's warranty obligation is limited, at Fluke's option, to refund of the purchase price, free of charge repair, or
replacement of a defective product which is returned to a Fluke authorized service center within the warranty period.
To obtain warranty service, contact your nearest Fluke authorized service center to obtain return authorization
information, then send the product to that service center, with a description of the difficulty, postage and insurance
prepaid (FOB Destination). Fluke assumes no risk for damage in transit. Following warranty repair, the product will be
returned to Buyer, transportation prepaid (FOB Destination). If Fluke determines that failure was caused by neglect,misuse, contamination, alteration, accident, or abnormal condition of operation or handling, including overvoltage
failures caused by use outside the product’s specified rating, or normal wear and tear of mechanical components,
Fluke will provide an estimate of repair costs and obtain authorization before commencing the work. Following repair,
the product will be returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and returntransportation charges (FOB Shipping Point).
THIS WARRANTY IS BUYER'S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES,EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT,INCIDENTAL, OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, ARISING FROMANY CAUSE OR THEORY.
Since some countries or states do not allow limitation of the term of an implied warranty, or exclusion or limitation ofincidental or consequential damages, the limitations and exclusions of this warranty may not apply to every buyer. If
any provision of this Warranty is held invalid or unenforceable by a court or other decision-maker of competentjurisdiction, such holding will not affect the validity or enforceability of any other provision.
Fluke Corporation
P.O. Box 9090
Everett, WA 98206-9090
U.S.A.
11/99
To register your product online, visit register.fluke.com

Fluke Europe B.V.
P.O. Box 1186
5602 BD Eindhoven
The Netherlands

TABLE OF CONTENTS

Table Of Contents
Table Of Contents .................................................................. III
Tables ................................................................................... IX
Figures ................................................................................... X
About This Manual ................................................................. XI
1.

Introduction ...................................................................... 1
1.1
1.2

Product Overview ................................................................................................................................... 1
Specifications ......................................................................................................................................... 1
1.2.1
1.2.2
1.2.2.1
1.2.2.2
1.2.2.3
1.2.3

2.

Installation ....................................................................... 5
2.1

Unpacking And Inspection .................................................................................................................... 5
2.1.1
2.1.2

2.2
2.3

2.4

Setup ....................................................................................................................................................... 6
Preparing For Operation .............................................................................................................................. 6
Front And Rear Panels ................................................................................................................................. 7
Front Panel ................................................................................................................................................. 7
Rear Panel ................................................................................................................................................. 8
Power Connection ........................................................................................................................................ 8Connecting To A Pressure Supply (Supply Port) ...................................................................................... 8Connecting A Vacuum Pump (Exhaust Port) ............................................................................................. 9Connecting External Q-RPTS In RPM4 Reference Pressure Monitor ...................................................... 9Connecting To The Device Under Test (Test(+) And Test(-) Ports)........................................................ 10
Installing a Self Purging Liquid Trap (SPLT) ............................................................................................ 12
Installing a Dual Volume Unit (DVU), G15K and BG15K Q-RPTS ........................................................... 12
The ATM Port .............................................................................................................................................. 12
Check/Set Security Level ........................................................................................................................... 12
Turn Off Absolute And Negative Gauge Mode
(AXXX RPT)........................................................ 13

Power-Up And Verification .................................................................................................................. 13
2.4.1
2.4.2
2.4.2.1
2.4.2.2
2.4.3
2.4.4
2.4.5
2.4.5.1
2.4.5.2

2.5

Removing From Packaging ......................................................................................................................... 5
Inspecting Contents ..................................................................................................................................... 5

Site Requirements .................................................................................................................................. 6
2.3.1
2.3.2
2.3.2.1
2.3.2.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
2.3.7.1
2.3.7.2
2.3.8
2.3.9
2.3.103.

General Specifications ................................................................................................................................. 1
Pressure Measurement Specifications ....................................................................................................... 2
Quartz Reference Pressure Transducer (Q-RPT) ...................................................................................... 2
Utility Sensor .............................................................................................................................................. 4
On-Board Barometer .................................................................................................................................. 4
Pressure Control Specifications ................................................................................................................. 4

Switch Power On ........................................................................................................................................ 13
Check Pressure Measurement Operation ................................................................................................ 13
Checking Absolute Mode Pressure Measurement ................................................................................... 13
Checking Gauge Mode Pressure Measurement ...................................................................................... 14
Leak Test ..................................................................................................................................................... 15
Purge ........................................................................................................................................................... 15
Check Pressure Control Operation ........................................................................................................... 15
Basic Interface .......................................................................................................................................... 15
Advanced Interface .................................................................................................................................. 15

Short Term Storage .............................................................................................................................. 16

Operating Principles ........................................................ 17
3.1
3.2

User Interfaces ..................................................................................................................................... 17
General Operating Principles .............................................................................................................. 17
3.2.1

Direct Pressure Control ............................................................................................................................. 17
Page IIIPPC4™ OPERATION AND MAINTENANCE MANUAL

3.2.2
3.2.2.1
3.2.2.2
3.2.3
3.2.4
3.2.5
3.2.6
3.2.7
3.2.8
3.2.9
3.2.103.2.11
3.2.123.2.133.2.143.2.153.2.163.2.173.2.183.2.193.2.203.2.21
3.2.21.1
3.2.22
3.2.22.1
3.2.22.2
3.2.233.2.243.2.253.2.25.1
3.2.25.2
3.2.25.3
3.2.25.4
3.2.25.5
3.2.263.2.26.1
3.2.26.2
3.2.26.3
3.2.26.4
3.2.26.5
3.2.273.2.27.1
3.2.27.2
3.2.27.3
3.2.27.4
3.2.27.5
3.2.27.6
3.2.283.2.293.2.29.1
3.2.29.2
3.2.29.3
3.2.29.4
3.2.29.5
3.2.29.6
3.2.29.7

4.

Automated Pressure Control ..................................................................................................................... 17
Dynamic Control ....................................................................................................................................... 18
Static Control ............................................................................................................................................ 19
Pressure Ready/Not Ready ........................................................................................................................ 19
Gauge and Negative Gauge Modes with an Axxx (Absolute) Q-RPT, Dynamic Compensation for
Atmospheric Pressure ............................................................................................................................... 21
Multiple Internal and External Q-RPTs ..................................................................................................... 22
Multiple Ranges (Q-RPTs, AutoRange and Infinite Ranging) ................................................................. 23
Operation with a PG7000 Piston Gauge ................................................................................................... 24
AutoRange................................................................................................................................................... 24
Range........................................................................................................................................................... 27
Unit............................................................................................................................................................... 27
Measurement Mode .................................................................................................................................... 28
Set Pressure Automatically ....................................................................................................................... 29
Control ......................................................................................................................................................... 30
Vent .............................................................................................................................................................. 31
AutoTest ...................................................................................................................................................... 31
Head ............................................................................................................................................................. 32
Purge ........................................................................................................................................................... 33
Leak Test ..................................................................................................................................................... 35
Resolution ................................................................................................................................................... 35
Jog ............................................................................................................................................................... 36
Pressure Limits........................................................................................................................................... 36
Over Pressure Function ........................................................................................................................... 37
AutoZero (AutoZ) ........................................................................................................................................ 38
Edit AutoZ ................................................................................................................................................. 41
Run AutoZ ................................................................................................................................................ 41
Drivers ......................................................................................................................................................... 42
Remote ........................................................................................................................................................ 42
Reset ............................................................................................................................................................ 43
Settings .................................................................................................................................................... 43
Units ......................................................................................................................................................... 44
AutoTest ................................................................................................................................................... 44
Calibration ................................................................................................................................................ 44
All ............................................................................................................................................................. 45
Preferences ................................................................................................................................................. 46
Screen Saver ............................................................................................................................................ 46
Sounds ..................................................................................................................................................... 46
Time ......................................................................................................................................................... 47
Language ................................................................................................................................................. 47
Security..................................................................................................................................................... 47
Internal Functions ...................................................................................................................................... 50
Identification ............................................................................................................................................. 50
Control Reference .................................................................................................................................... 50
Barometer ................................................................................................................................................. 51
Purge ........................................................................................................................................................ 52
Log ........................................................................................................................................................... 52
TEST (-) Vent ........................................................................................................................................... 52
Calibration ................................................................................................................................................... 53
Measurement Uncertainty .......................................................................................................................... 53
Product Uncertainty .................................................................................................................................. 54
Head ......................................................................................................................................................... 55
Zero Stability............................................................................................................................................. 55
Control Uncertainty ................................................................................................................................... 55
Combining uncertainties ........................................................................................................................... 56
Delivered Pressure Uncertainty ................................................................................................................ 57
Using Values Other Than Default ............................................................................................................. 57

Basic User Interface ........................................................ 59
4.1
4.2

Main Run Screen .................................................................................................................................. 59
Keypad and Controls ........................................................................................................................... 61
4.2.1
4.2.1.1
4.2.1.2
4.2.2

4.3

Basic Interface menus ......................................................................................................................... 63
4.3.1

4.4

Set Pressure Automatically ....................................................................................................................... 61
Interrupting Automated Pressure Control ................................................................................................. 62
Automated Pressure Commands for Zero Pressure ................................................................................ 62
Vent .............................................................................................................................................................. 63
Main Menu Tree .......................................................................................................................................... 63

Menu Tree Operation ........................................................................................................................... 64
4.4.1
4.4.1.1<Setup>, <Range> ...................................................................................................................................... 64
Saving An AutoRanged Range ................................................................................................................ 64

Page IVTABLE OF CONTENTS

4.4.1.2
4.4.2
4.4.3
4.4.4
4.4.4.1
4.4.5
4.4.5.1
4.4.5.2
4.4.6

4.5<Spec> (Special) ................................................................................................................................... 68
4.5.1
4.5.1.1
4.5.1.2
4.5.2
4.5.2.1
4.5.2.2
4.5.2.3
4.5.2.4
4.5.2.5
4.5.3
4.5.4
4.5.4.1
4.5.4.2
4.5.4.3
4.5.4.4
4.5.5
4.5.5.1
4.5.5.2
4.5.5.3
4.5.5.4
4.5.5.5
4.5.6
4.5.7
4.5.7.1
4.5.7.2
4.5.7.3
4.5.7.4
4.5.7.5
4.5.8
4.5.9
4.5.104.5.11
4.5.124.5.134.5.144.5.154.5.164.5.17

5.

Deleting AutoRange Ranges .................................................................................................................... 65<Setup>, <Res> (Resolution) ..................................................................................................................... 65<Setup>, <Jog> ........................................................................................................................................... 65<Setup>, <UL> (Upper Limit) ..................................................................................................................... 66
Over Pressure Function ........................................................................................................................... 66<Setup>, <Control> .................................................................................................................................... 67<Limits> (Custom Control Parameters) .................................................................................................... 67
Turning-Off Custom Control Parameters .................................................................................................. 68<Setup>, <Drv> (Drivers)............................................................................................................................ 68<Spec>, <AutoZ> ........................................................................................................................................ 69
Edit AutoZ ................................................................................................................................................. 70
Run AutoZ ................................................................................................................................................ 70<Spec>, <Remote> ..................................................................................................................................... 71<COM1> and <COM2> ............................................................................................................................ 71<IEEE-488> .............................................................................................................................................. 71<Format> .................................................................................................................................................. 71<RS232test> ............................................................................................................................................ 72<Ethernet> ................................................................................................................................................ 72<Spec>, <Head> .......................................................................................................................................... 73<Spec>, <Reset> ......................................................................................................................................... 73<Set> ........................................................................................................................................................ 73<Units> ..................................................................................................................................................... 74<Cal> ........................................................................................................................................................ 74<All> ......................................................................................................................................................... 74<Spec>, <Prefs>.......................................................................................................................................... 74<ScrSvr> .................................................................................................................................................. 75<Sound> ................................................................................................................................................... 75<Time> ..................................................................................................................................................... 75<ID> .......................................................................................................................................................... 75<Level> (Security) .................................................................................................................................... 76<Spec>, <Punit>.......................................................................................................................................... 77<Spec>, <Internal>...................................................................................................................................... 78<Config> ................................................................................................................................................... 78<Control Ref> ........................................................................................................................................... 78<Baro> ...................................................................................................................................................... 79<Purge> .................................................................................................................................................... 79<Lo Vnt> ................................................................................................................................................... 80<Spec>, <Cal> ............................................................................................................................................. 80<Spec>, <Log> ............................................................................................................................................ 81<ARange> .................................................................................................................................................... 81<Leak> ......................................................................................................................................................... 82<RPT> .......................................................................................................................................................... 83<Unit> .......................................................................................................................................................... 84<Range> ...................................................................................................................................................... 84<Mode> ........................................................................................................................................................ 85<Head>......................................................................................................................................................... 85<Purge> ....................................................................................................................................................... 85

Advanced User Interface .................................................. 87
5.1

Main Run Screen .................................................................................................................................. 87

5.2

Other Screens ....................................................................................................................................... 89

5.3

Keypad Layout and Protocol ............................................................................................................... 90

5.4

Conventions for the Advanced Interface ............................................................................................ 90
5.4.1
5.4.2

5.5

Pressure Control .................................................................................................................................. 93
5.5.1
5.5.1.1
5.5.1.2
5.5.2
5.5.3

5.6

Set Pressure Automatically ....................................................................................................................... 93
Interrupting Automated Pressure Control ................................................................................................. 94
Automated Pressure Commands for Zero Pressure ................................................................................ 94
Manual Pressure Control ........................................................................................................................... 94
Vent .............................................................................................................................................................. 95

Advanced Interface Menus .................................................................................................................. 95
5.6.1
5.6.2

5.7

Navigation Controls and Keypad .............................................................................................................. 90
Navigating Advanced Interface Menus ..................................................................................................... 91

Shortcuts ..................................................................................................................................................... 95
Menu Structure ........................................................................................................................................... 95

Menu operation..................................................................................................................................... 96
5.7.1
5.7.2

AutoRange................................................................................................................................................... 96
AutoTest ...................................................................................................................................................... 99

Page VPPC4™ OPERATION AND MAINTENANCE MANUAL

5.7.2.1
5.7.2.2
5.7.2.3
5.7.3
5.7.3.1
5.7.3.2
5.7.4
5.7.5
5.7.5.1
5.7.5.2
5.7.5.3
5.7.6
5.7.6.1
5.7.6.2
5.7.6.3
5.7.6.4
5.7.7
5.7.7.1
5.7.7.2
5.7.7.3
5.7.7.4
5.7.7.5
5.7.7.6
5.7.8
5.7.8.1
5.7.8.2
5.7.8.3
5.7.9
5.7.9.1
5.7.9.2
5.7.9.3
5.7.9.4
5.7.105.7.11
5.7.12
5.7.12.1
5.7.12.2
5.7.12.3
5.7.12.4
5.7.12.5

6.

Exercise .................................................................................................................................................... 99
Quick Test .............................................................................................................................................. 100
Advanced Test ....................................................................................................................................... 102
Pressure .................................................................................................................................................... 106
Purge ...................................................................................................................................................... 106
Leak Test ................................................................................................................................................ 107
Drivers ....................................................................................................................................................... 108
System ....................................................................................................................................................... 108
Run AutoZ .............................................................................................................................................. 108
Control Configuration ............................................................................................................................. 109
Reset ...................................................................................................................................................... 110
Pressure .................................................................................................................................................... 111
Pressure Unit .......................................................................................................................................... 111
Measurement Mode ............................................................................................................................... 113
Head ....................................................................................................................................................... 113
Resolution .............................................................................................................................................. 114
Preferences ............................................................................................................................................... 115
Screen Saver .......................................................................................................................................... 115
Sounds ................................................................................................................................................... 115
Time ....................................................................................................................................................... 116
Language ............................................................................................................................................... 116
Security................................................................................................................................................... 117
Edit Security Password........................................................................................................................... 117
Control ....................................................................................................................................................... 118
Pressure Limits ....................................................................................................................................... 118
Pressure Control .................................................................................................................................... 119
Jog Step ................................................................................................................................................. 120
Remote ...................................................................................................................................................... 120
COM1 and COM2 ................................................................................................................................... 121
Command Format................................................................................................................................... 121
IEEE-488 ................................................................................................................................................ 121
Ethernet .................................................................................................................................................. 121
Calibration ................................................................................................................................................. 122
Uncertainty ................................................................................................................................................ 122
Internal....................................................................................................................................................... 122
ID ............................................................................................................................................................ 122
Control Reference .................................................................................................................................. 123
Purge ...................................................................................................................................................... 123
Event log ................................................................................................................................................ 123
TEST (-) Vent ......................................................................................................................................... 124

Remote Operation ...........................................................125
6.1
6.2

Overview ............................................................................................................................................. 125
PPC4 Cockpit ...................................................................................................................................... 125
6.2.1
6.2.2
6.2.2.1
6.2.3
6.2.3.1
6.2.3.2
6.2.3.3

6.3

Remote Interfacing ............................................................................................................................. 131
6.3.1
6.3.1.1
6.3.1.2
6.3.1.3
6.3.2
6.3.2.1
6.3.3
6.3.4

6.4

RS232 Interface......................................................................................................................................... 131
COM1 ..................................................................................................................................................... 131
COM2 ..................................................................................................................................................... 131
RS232 Command Testing ...................................................................................................................... 132
IEEE-488 .................................................................................................................................................... 135
IEEE-488 Remote Command testing ..................................................................................................... 135
USB ............................................................................................................................................................ 136
Ethernet (Optional) ................................................................................................................................... 136

Programming Formats ....................................................................................................................... 137
6.4.1
6.4.2
6.4.2.1
6.4.2.2

6.5

Overview .................................................................................................................................................... 125
Installation................................................................................................................................................. 125
USB Driver Installation ........................................................................................................................... 125
Running the Cockpit ................................................................................................................................ 128
USB Interface ......................................................................................................................................... 129
RS232 Interface ..................................................................................................................................... 129
Keyboard Shortcuts ................................................................................................................................ 130

Classic Program Message Format .......................................................................................................... 137
Enhanced Program Message Format ..................................................................................................... 137
Using Command Type Commands ........................................................................................................ 138
Using Query Type Commands .......................................................................................................... 139

Commands .......................................................................................................................................... 139
6.5.1
6.5.2
6.5.3
6.5.4

Programming Messages .......................................................................................................................... 139
Error Messages......................................................................................................................................... 141
Program Message Description Overview ............................................................................................... 142
Program Message Descriptions .............................................................................................................. 143
Page VI

TABLE OF CONTENTS

6.6

Status Reporting System ................................................................................................................... 175
6.6.1
6.6.2
6.6.3
6.6.4

6.7

IEEE STD. 488.2 Common And Status Program Messages ............................................................ 178
6.7.1

7.

Error Queue............................................................................................................................................... 175
Status Byte Register ................................................................................................................................ 175
Standard Event Register .......................................................................................................................... 177
Ready Status Register ............................................................................................................................. 177
Program Message Descriptions .............................................................................................................. 178

Maintenance, Adjustments and Calibration .......................183
7.1
7.2

Overview ............................................................................................................................................. 183
Calibration of Quartz Reference Pressure Transducers (Q-RPTs)................................................. 183
7.2.1
7.2.1.1
7.2.1.2
7.2.2
7.2.3
7.2.4
7.2.4.1
7.2.4.2
7.2.5
7.2.5.1
7.2.5.2
7.2.6
7.2.7
7.2.7.1
7.2.7.2
7.2.7.3
7.2.8
7.2.8.1
7.2.8.2

7.3

Adjustment of an On-board Barometer ............................................................................................ 196
7.3.1
7.3.2

7.4
7.5

Principle .................................................................................................................................................... 183
PA and PM Coefficients ......................................................................................................................... 184
As Received and As Left Data ............................................................................................................... 185
Equipment Required ................................................................................................................................ 185
Set-up and Preparation ............................................................................................................................ 186
Recommended Calibration Point Sequence .......................................................................................... 186
Standard and Full Scale Standard Class Q-RPTs ................................................................................. 187
Premium Class Q-RPTs ......................................................................................................................... 188
Turning Off Absolute and Negative Gauge Measurement Modes for Axxx (Absolute) Q-RPTs ........ 190
Basic Interface ........................................................................................................................................ 190
Advanced Interface ................................................................................................................................ 190
Q-RPT Calibration Using CalTool for RPTs Software ........................................................................... 191
Editing and Viewing Q-RPT Calibration Information ............................................................................. 191
Basic Interface ........................................................................................................................................ 192
Advanced Interface ................................................................................................................................ 192
Q- RPT Uncertainty ................................................................................................................................ 193
Q-RPT Calibration/Adjustment without CalTool for RPTs Software .................................................... 194
Basic Interface Operation ....................................................................................................................... 194
Advanced Interface Operation ................................................................................................................ 195
Basic Interface .......................................................................................................................................... 196
Advanced Interface................................................................................................................................... 196

Adjustment of Utility Sensor ............................................................................................................. 197
Pneumatic Control Module Configuration ....................................................................................... 197
7.5.1
7.5.2

Basic Interface Operation ........................................................................................................................ 198
Advanced Interface Operation ................................................................................................................. 199

7.6

Reloading Embedded Software into Flash Memory ........................................................................ 199

7.7

Removing the PPC4 Cover ................................................................................................................ 200

7.8Overhaul .............................................................................................................................................. 200

7.9

Subassembly Description and Location .......................................................................................... 201
7.9.1
7.9.2
7.9.3
7.9.3.1
7.9.3.2
7.9.4
7.9.5
7.9.6
7.9.7
7.9.8

7.10

Power Supply Module .............................................................................................................................. 202
PowerPC Board ........................................................................................................................................ 202
Q-RPT MODULE ........................................................................................................................................ 202
Hi Q-RPT or Utility Sensor...................................................................................................................... 202
Lo Q-RPT ............................................................................................................................................... 202
On-board Barometer ................................................................................................................................ 202
Vacuum Sensor ........................................................................................................................................ 203
Pressure Control Module ......................................................................................................................... 203
Display ....................................................................................................................................................... 203
Driver Board .............................................................................................................................................. 203

Pneumatic Schematics ...................................................................................................................... 204
7.10.1
7.10.2Pressure Control Module ......................................................................................................................... 204
Q-RPT Module Configurations ................................................................................................................ 205

8.

Troubleshooting .............................................................207

9.

Appendix .......................................................................211
9.1
9.2

Drivers ................................................................................................................................................. 211
Unit Conversion .................................................................................................................................. 212
9.2.1

Pressure .................................................................................................................................................... 212

Page VIIPPC4™ OPERATION AND MAINTENANCE MANUAL

10. Warranty ........................................................................213
10.1

Overview ............................................................................................................................................. 213

11. Glossary ........................................................................215

Page VIIITABLES & FIGURES

TablesTable 1. Reference Pressure Transducer (Q-RPT) Designations and Ranges .......................................... 2
Table 2. PPC4 Packing List ......................................................................................................................... 5
Table 3. Position Designators of Q-RPTs in a PPC4 System ................................................................... 23
Table 4. Settings and What They Are Specific To (Range, Measurement Mode, Q-RPT, System) ......... 24
Table 5. Settings Made by AutoRange ....................................................................................................... 25
Table 6. Default Pressure Control Parameters .......................................................................................... 31
Table 7. AutoZ ON and OFF ...................................................................................................................... 40
Table 8. Reset Settings .............................................................................................................................. 43
Table 9. Reset Calibration ......................................................................................................................... 45
Table 10. Reset All ..................................................................................................................................... 45
Table 11. Security Levels, Advanced Interface ......................................................................................... 49
Table 12. Security Levels, Basic Interface ................................................................................................. 49
Table 13. Default Values for PPC4 Uncertainty Components ................................................................... 56
Table 14. Unit Function - Available Units of Measure................................................................................ 77
Table 15. Main Run Screen Fields and Buttons ........................................................................................ 88
Table 16. Lower Level Screen Displays and Selectable Fields ................................................................. 89
Table 17. Advanced Interface Menu Structure .......................................................................................... 96
Table 18. PPC4 Cockpit Keyboard Shortcuts .......................................................................................... 130
Table 19. COM1 Pin Designations and Connections .............................................................................. 131
Table 20. COM2 DB-9F Pin Designations ............................................................................................... 132
Table 21. Program Message List ............................................................................................................. 139
Table 22. Error #s and Descriptions ........................................................................................................ 141
Table 23. 8 Bit Status Byte Register ........................................................................................................ 175
Table 24. 8 Bit Standard Event Register.................................................................................................. 177
Table 25. 8 Bit Ready Status Register ..................................................................................................... 177
Table 26. Program Message List ............................................................................................................. 178
Table 27. Calibration Point Sequence, Standard Class, Axxx and Gxxx Q-RPTs .................................. 187
Table 28. Calibration Point Sequence, Standard Class, BGxxx Q-RPTs ................................................ 188
Table 29. Calibration Point Sequence, Standard Class, BA100K Q-RPT ............................................... 188
Table 30. Calibration Point Sequence, Premium Class, Axxx and Gxxx Q-RPTs .................................. 189
Table 31. Calibration Point Sequence, Premium Class, BGxxx Q-RPTs ................................................ 189
Table 32. Troubleshooting Guide............................................................................................................. 207
Table 33. External Drivers Current Output .............................................................................................. 211
Table 34. External Drivers Pin Outs......................................................................................................... 211
Table 35. Pressure Unit of Measure Conversion Coefficients ................................................................. 212
Table 36. DHI Authorized Service Providers ........................................................................................... 213

Page IXPPC4™ OPERATION AND MAINTENANCE MANUAL

FiguresFigure 1. PPC4 advanced interface front panel ........................................................................................... 7
Figure 2. PPC4 basic interface front panel .................................................................................................. 7
Figure 3. Rear panel with optional connectors ............................................................................................ 8
Figure 4. Dynamic Pressure Control Operation ......................................................................................... 18
Figure 5. Static Pressure Control Operation .............................................................................................. 19
Figure 6. Ready/Not Ready in Dynamic Pressure Control Mode .............................................................. 20
Figure 7. Ready/Not Ready in Static Control Mode ................................................................................... 21
Figure 8. Product Uncertainty Illustration .................................................................................................... 54
Figure 9. Main Run Screen Display Fields ................................................................................................ 60
Figure 10. Basic PPC4 Keypad Layout...................................................................................................... 61
Figure 11. Main Run Screen Display and Selectable Fields (see Table 15) ............................................. 87
Figure 12. Advanced Interface Lower Level Screen Example (see Table 16) .......................................... 89
Figure 13. Keypad layout ........................................................................................................................... 90
Figure 14. AutoRange Bar ......................................................................................................................... 98
Figure 15. Windows Hardware Wizard .................................................................................................... 126
Figure 16. Driver Location ........................................................................................................................ 126
Figure 17. Browse for Driver Location ..................................................................................................... 127
Figure 18. Driver Warning Message ........................................................................................................ 127
Figure 19. Driver Setup Complete ........................................................................................................... 128
Figure 20. PPC4 Cockpit Main Display ..................................................................................................... 128
Figure 21. PPC4 Cockpit Communication Selection ................................................................................ 129
Figure 22. PPC4 Cockpit Communication Selection ................................................................................ 129
Figure 23. PPC4 Cockpit RS232 Settings ................................................................................................ 129
Figure 24. PPC4 Cockpit Pressure Control Buttons ................................................................................. 130
Figure 25. Windows selection of Hyperterminal ...................................................................................... 132
Figure 26. Hyperterminal Initial Display ................................................................................................... 132
Figure 27. Hyperterminal ASCII Setup..................................................................................................... 134
Figure 28. Status Register Schematic ..................................................................................................... 176
Figure 29. Removing Back Cover ............................................................................................................ 200
Figure 30. Internal View ........................................................................................................................... 201
Figure 31. Pressure Control Module Schematic ...................................................................................... 204
Figure 32. Q-RPT Module Schematics for Various Configurations ......................................................... 206
Figure 33. Drivers Connector Schematic ................................................................................................. 211

Page XABOUT THIS MANUAL

About This ManualThis manual is intended to provide the user with the basic information necessary to operate a PPC4
pressure controller/calibrator. It also includes a great deal of additional information provided to allow you
to optimize PPC4 use and take full advantage of its many features and functions.
Before using the manual, take a moment to familiarize yourself with the Table of Contents structure:
Sections 1, 2 and 3 should be read by all first time PPC4 users. Section 4 is important for those needing
to communicate in local mode with the Basic user interface. Section 5 is important for those using theAdvanced user interface. Section 6 is for remote operation from an external computer. Section 7 provides
maintenance and calibration information. Section 8 is a quick troubleshooting guide. Use it totroubleshoot unexpected PPC4 behavior based on the symptom of that behavior. Certain words andexpressions have specific meaning as they pertain to PPC4. The Glossary, Section 11 is useful as aquick reference for exact definition of specific words and expressions as they are used in the manual.

Note
For those who “don’t read manuals”, go directly to Section 2.3 to set up your PPC4
and then go to Section 2.4 for power-up and verification. This will get you up andrunning quickly with a minimal risk of causing damage to yourself or your new
PPC4. THEN…when you have questions or start to wonder about all the greatfeatures you might be missing, get into the manual!

Manual Conventions
Note•

This manual is written for both the basic PPC4 and the PPC4-ui.
Throughout the manual the local interface for the PPC4-ui, which has alarge color graphics display and is typically used in bench top applications,is referred to as the Advanced user interface or Advanced Interface. In turnthe limited function local interface for the basic PPC4, which is typicallycontrolled by a remote computer, is referred to as the Basic user interface
or Basic Interface.

•

When the term “PPC4” is used alone, it typically refers to both basic PPC4and PPC4-ui collectively since the only difference between the two is the
local user interface.

•

Detailed description of menu structure, key press sequences andconventions for the Advanced user interface are found in Section 5.

•

Detailed description of menu structure, key press sequences andconventions for the basic user interface are found in Section 4.

•

For dedicated front panel keys, such as , , , and , any time akey is shown in the manual, it should be interpreted to mean “press thiskey”. For example:  to return to the Main Run Screen means “Press the button to return to the Main Run Screen”.

•

For users of the electronic (pdf) version of this manual, there is extensive
use of hot links for the table of contents, figure references, table references
and all section references found throughout. Simply click on a reference tofollow the live link.

Page XIPPC4™ OPERATION AND MAINTENANCE MANUAL Caution“Caution” is used in throughout the manual to identify conditions or actions that
could cause harm to the PPC4 or to the devices that are connected to the PPC4.

 Warning“Warning” is used in throughout the manual to identify actions that could pose ahazard to the user of the PPC4.

Note“Note” is used throughout the manual to identify operating and applications advice
and additional explanations.

Page XII1. INTRODUCTION

1.

Introduction

1.1

Product Overview

PPC4 is a stand-alone pressure controller intended for precision setting and control of gas pressure into
a closed volume as is commonly needed for the calibration and testing of pressure measuring
instruments. It has been designed to provide very high performance combined with maximum versatility andease of use.
PPC4 can be equipped with a low cost utility sensor for pressure monitoring or one or two Quartz Reference
Pressure Transducers (Q-RPTs) to allow it to set and measure pressure with very low measurement
uncertainty. Up to two external Q-RPTs in an external Reference Pressure Monitor (RPM4) can also be
integrated into a PPC4 system. In some cases, a barometer is included.
Pressure control is achieved by a patented pneumatic module based on digitally controlled solenoid
valves and differential pressure regulators.
PPC4 is controlled locally by the operator using a front panel display, keypad and function keys or
remotely by a computer using ASCII character command strings over RS232, IEEE-488.2 or Ethernet.
PPC4 models are available to measure and control pressure in ranges from as low as - 3 to 3 kPa (0.4 psi)
to as high as 0 to 14 MPa (0 to 2 000 psi) in absolute, gauge and compound gauge measurement modes.

1.2

Specifications
1.2.1

General Specifications

Power Requirements
Operating Temperature Range
Storage Temperature Range
Vibration
WeightDimensions
Ventilation
Ventilation
Microprocessors
Remote communication interfaces
Fuses

Pressure Ranges
Operating Medium

100 to 240 VAC (-15%, +10%), 50-60 Hz, 70 VA max consumption
10 to 40 °C-20 to 70 °C
Meets MIL-PRF-28800F Class 3
16.6 kg (36.5 lb)
PPC4: 19 cm H x 35 cm W x 41 cm D (7.5 in. x 13.8 in. x 16.1 in.)
PPC4-ui: 19 cm H x 35 cm W x 45 cm D (7.5 in. x 13.8 in. x 17.7 in.)To prevent product overheating, provide proper ventilation. Allow 10 cm (4 in.)clearance from rear panel cooling fan.
Motorola 68302, 16 MHz
RS232 (COM1, COM2), USB (front panel)
Optional: IEEE-488.2, Ethernet and rear panel USB
1 A, 250 VAC fuse, 5 x 20 mm, time lag type fuse. Internal power supply fuse
not replaceable by operator: 2A, 250 V (UV 440-2 power supply), 3.15A, 250 V(NFS40-7612 power supply)
Vacuum to 14 MPa (2 000 psi). Low uncertainty measurement provided by
selection of quartz reference pressure transducer(s) (Q-RPTs)
Any clean, dry, non-corrosive gas

 Warning
User is responsible for any and all safety precautions
associated with hazardous, flammable or toxic gas ventilationand containment.
Pressure Connections

TEST (+), TEST (-): 1/8 in. NPT FSUPPLY: 1/8 in. NPT F
EXHAUST: 3/8 in. NPT F
ATM: 10-32 UNF

Page 1

PPC4™ OPERATION AND MAINTENANCE MANUAL

Pressure Limits

1.2.2

Maximum working:pressure:
Maximum test pressure:w/out damage:
Recommended supply: pressure:

Hi Q-RPT maximum
115 % Hi Q-RPT maximum
Maximum control pressure + 10 %Pressure Measurement Specifications
1.2.2.1

Quartz Reference Pressure Transducer (Q-RPT)

Quartz reference pressure transducers (Q-RPTs) can be installed in PPC4 to obtainlow uncertainty pressure measurement. One or two Q-RPTs can be included in the
PPC4 and/or additional Q-RPTs can be used externally mounted in a DHI RPM4
Reference Pressure Monitor (see Section 3.2.5).
The type (Axxx, Gxxx, BGxxx, BAxxx) and range of the Q-RPT module(s)determines the PPC4 measurement specifications.
All Q-RPTs whose maximum pressure is over 200 kPa (30 psi) are of the absolutepressure type (Axxx) using an evacuated, permanently sealed reference. Axxx Q-RPTs
can measure absolute, gauge and negative gauge pressure. Gauge pressure with
an Axxx (absolute) Q-RPT is obtained by offsetting atmospheric pressure andapplying dynamic compensation for atmospheric changes using the on-board
barometer (see Section 3.2.4). Gxxx (gauge) Q-RPTs can measure positive gaugepressure only. BGxxx (bi-directional gauge) Q-RPTs can measure gauge andnegative gauge pressure. See Section 3.2.11 for additional information on absolute,gauge and negative gauge measurement modes.
PPC4s configured with two Q-RPT modules have only one TEST(+) and TEST(-) port.
PPC4 internal valves and logic handle switching between the two Q-RPTs as needed.

Note
Q-RPTs are available with three different performance levels,
PREMIUM class, STANDARD class, and FULL SCALESTANDARD class. See the product label on the PPC4 rear
panel, the label on the Q-RPT module on the rear panel and/or
the product calibration reports to determine the class of the
Q-RPTs installed in PPC4.
Table 1. Reference Pressure Transducer (Q-RPT) Designations and Ranges
SI VERSIONRPTDESIGNATIONMAXIMUM
PRESSURE
Absolute[kPa]

US VERSIONMAXIMUM
PRESSURE
Gauge
[kPa]

MAXIMUM
PRESSURE
Absolute[psi]

MAXIMUM
PRESSURE
Gauge
[psi]

A14M

1

14 000

14 000

2 000

2 000

A10M

1

10 000

10 000

1 500

1 500

7 000

7 000

1 000

1 000

3 500

3 500

500

500

2 000

2 000

300

300

1

1 400

1 400

200

200

A700K

1

700

700

100

100

A350K

1

350

250

50

35

A200K

1

200

100

30

15

A160K

1

160

60

23

8

A7M

1

A3.5M
A2M

1

1

A1.4M

Page 2

1. INTRODUCTIONSI VERSIONUS VERSIONMAXIMUM
PRESSURE
Absolute[kPa]

MAXIMUM
PRESSURE
Gauge
[kPa]

MAXIMUM
PRESSURE
Absolute[psi]

MAXIMUM
PRESSURE
Gauge
[psi]

1

110

10

16

1.5

G200K

2

--

200

--

30

G100K

2

--

100

--

15

--

15

--

2.2

3

--

-15 to 15---2.2 to 2.2

RPT
DESIGNATION

A100K

G15K

2

BG15K

BA100K
1.
2.
3.
4.

4

70 to 110-10.2 to 16--

All AXXXX RPTs support absolute, gauge and compound (negative) gauge modes.
All GXXXX RPTs are positive gauge mode only.
BG15K is bi-directional gauge from - 15 to + 15 kPa (- 2.2 to + 2.2 psi).
BA100K is a barometric range whose low point is 70 kPa absolute (10 psi).

Warm Up Time

None required, 30 minute temperature stabilization recommended for best performance fromcold power up

Resolution

To 1 ppm, user adjustable

Acceleration Effect± 0.008 % /g maximum, worst axis
Allows operation at ± 20° from reference plane without significant effect1

Predicted One Year Stability± 0.005% of reading (gauge mode, or absolute with regular use of AutoZero)
Full Scale Standard (f)Precision

2

3

Measurement Uncertainty

Standard (s)Premium (p)4± 0.011% of AutoRanged span

± 0.008% of reading or 0.0024%
of Q-RPT span, whicheveris greater 5± 0.005% of reading, 0.0015% of
AutoRanged span, or 0.0005% of
Q-RPT span, whicheveris greater6± 0.015% of AutoRanged span4± 0.01% of reading or 0.0030%
of Q-RPT span, whicheveris greater5± 0.008 % of reading, 0.0024% of
AutoRanged span, or 0.0007% of
Q-RPT span, whicheveris greater6

1. Predicted Q-RPT measurement stability limit (k=2) over one year assuming regular use of AutoZero function. AutoZero occurs automatically in gauge mode
whenever vented, by comparison with barometric reference in absolute mode. Absolute mode predicted one year stability without AutoZ is ± (0.005% Q-RPT
span + 0.005% of reading).
2. Combined linearity, hysteresis, repeatability. Add + 1 Pa (0.00015 psi) in gauge mode with an Axxx (absolute) Q-RPT for the resolution and short term stabilityof the on-board barometer.
3. Maximum deviation of the Q-RPT indication from the true value of applied pressure including precision, predicted one year stability limit, temperature effect andcalibration uncertainty, combined and expanded (k=2) following the ISO “Guide to the Expression of Uncertainty in Measurement.”
4. % of AutoRanged span, but with AutoRanged span no lower than 30% of Q-RPT span (10% with BG15K and G15K). For example, if the Q-RPT is a Full Scale
Standard A160K, the Measurement Uncertainty in pressure is 0.015% times the AutoRanged span for any AutoRanged span from 160 kPa to 48 kPa (160 kPa
span x 30%) and 7.2 Pa (160 kPa span x 30% x 0.015%) for any AutoRanged span less than 48 kPa.
5. % of reading value times measured pressure from 100 to 30 % of Q-RPT span. Under 30 % of Q-RPT span, % of reading value times 30 % of Q-RPT span.
For example, if the Q-RPT is a Standard A160K, the Measurement Uncertainty in pressure is 0.010% times the measured pressure to 48 kPa (160 kPa span x30%) and 0.0048 kPa (160 kPa span x 30% x 0.01%) under 48 kPa.
6. % of reading value times measured pressure from 100 to 30 % of AutoRanged span. Under 30% of AutoRanged span, % of reading value times 30% of
AutoRanged span. If AutoRanged span is less then 30% of maximum Q-RPT span, % of reading values times measured pressure, or % of reading times 9% of
Q-RPT span, whichever is greater. For example, if the Q-RPT is a Premium A160K and AutoRanged span is 160 kPa, the Measurement Uncertainty inpressure is measured pressure x 0.008% to 48 kPa (160 kPa AutoRanged span x 30%) and 0.0038 kPa (160 kPa span x 30% x 0.008%) under 48 kPa. If the
AutoRanged span is 100 kPa (greater than 30% of 160 kPa maximum Q-RPT span), the measurement uncertainty in pressure is measured pressure x 0.008%
to 30 kPa (100 kPa AutoRanged span x 30%) and 0.0024 kPa (100 kPa span x 30% x 0.008%) under 30 kPa. If the AutoRanged span is 30 kPa (less than 30%of the 160 kPa maximum Q-RPT span), the measurement uncertainty in pressure is measured pressure x 0.008% to 14.4 kPa (160 kPa maximum Q-RPT spanx 9%) and 0.0012 kPa (160 kPa maximum Q-RPT span x 9% x 0.008%) under 14.4 kPa.
Note: DHI technical note 8050TN11 provides a detailed description of PPC4 Q-RPT uncertainties.

Page 3

PPC4™ OPERATION AND MAINTENANCE MANUAL

1.2.2.2

Utility Sensor

The PPC4 may be configured with a Utility sensor instead of a Hi Q-RPT. Utility
sensors are used for pressure control, system monitoring and safety functions. They
are intended for indication only, not to provide reference pressure measurement.
Q-RPTs (see Section 1.2.2.1) are used for reference measurement.
Warm Up Time

None required

Ranges14 MPa (2 000 psi) absolute and gauge
7 MPa (1 000 psi) absolute and gauge
2 MPa (300 psi) absolute and gauge
700 kPa (100 psi) absolute and gauge
300 kPa (45 psi) absolute / 200 kPa (30 psi) gauge

Resolution

0.001 % of span

Precision

0.1 % of span

1.2.2.3

On-Board Barometer

The on-board barometer is used only to measure changes in atmosphericpressure to provide dynamic compensation of the Q-RPT’s atmospheric pressure
offset when using an Axxx (absolute) Q-RPT to make gauge pressure
measurements.
Warm Up Time
Range

None required
70 to 110 kPa (10 to 16 psi)

Resolution

0.001 % of span

Precision

0.1 % of span

Predicted Stability

0.05 kPa/yr (0.008 psi/yr)

Note
The on-board barometer is only present in PPC4s that have an
Axxx (absolute), BG15K (bi-directional gauge) or G15K (gauge)internal Q-RPT.

1.2.3

Pressure Control Specifications
Control Precision±0.0004% of Q-RPT span or ±0.00004% of Hi Q-RPT span,
whichever is greater or ±0.0008% of Q-RPT span if active QRPT is external.

Lowest controllable Pressure(gauge mode)

Zero set by automated venting. Lowest point above or below
zero limited only by Q-RPT resolution and control precision.

Lowest controllable Pressure(absolute, negative gauge modes)

0.05% of Q-RPT span or 1 kPa, whichever is greater

Ultimate Pressure(absolute, negative gauge)
Depending on vacuum pump and connections

50 Pa (0.5 mbar, 0.007 psia) typical with low ultimate pressure
option200 to 700 Pa (2 to 7 mbar, 0.03 to 0.1 psia) without low
ultimate pressure option

Typical Pressure Setting Ready Time
(0.005% hold limit, 50 cc test volume)
Slew Time(ATM to FS with 50 cc test volume)
Typical Test Volume

15 to 35 s
30 s
0 to 1000 cc for Q-RPT span 2 MPa [300 psi] or lessto 500 cc for Q-RPT span greater than 2 MPa [300 psi]

Default Dynamic Control Hold Limit

Page 4± 0.005 % of current range02. INSTALLATION

2.

Installation

2.1

Unpacking And Inspection
2.1.1

Removing From Packaging

PPC4 is delivered in a corrugated container with suspension packaging; or in an optional
molded shipping case with custom foam inserts.
Remove the PPC4 and its accessories from the shipping container and remove each elementfrom its protective plastic bag.

2.1.2

Inspecting Contents

Check that all items are present and have no visible damage.
A PPC4 includes all items indicated in Table 2.
Table 2. PPC4 Packing List
DESCRIPTIONPART #

1 ea.

PPC4 Pressure Controller/Calibrator

3336095

1 ea.

Calibration Report

3152121

1 ea.

Test Report

3126112ACCESSORIES:

3305585(3305597)

1 ea.

Operation and Maintenance Manual

3306047

1 ea.

Drivers Connector

3069838

1 ea.

USB Cable, 2 Meter, Shielded

1626219

1 ea.

Power Cord (7.5 ft.)

3133781(3153005)

1 ea.

General Accessories CD

3139043

2 ea.

Bulkhead Retainer, ½ in. hex

3138166

2 ea.

M4 Split Lock Washer

3153914

2 ea.

M4 x 8 Screw, BHSC

3361394

2 ea.

M3 x 20 Screw, SHC

3133921

Page 5

PPC4™ OPERATION AND MAINTENANCE MANUAL

2.2

Site Requirements

The PPC4 can be installed on any flat, stable surface at a convenient height. The front feet can beextended so that the unit can be inclined for easier viewing. The PPC4 can also be mounted in astandard 19 in. rack using the optional rack mount kit.
Minimizing the distance between the PPC4 and the device or system under test will enhance control
performance and reduce pressure setting times.
Ready access to the PPC4 rear panel should be considered to facilitate making and breaking
pressure connections.
Pneumatic and communications connections to a RPM4 pressure monitor should be considered if a RPM4
pressure monitor will be used as an external reference pressure measurement device (see Section 2.3.6).
The Self Purging Liquid Trap (SPLT), if used, should be mounted vertically at the low point of theconnection between the PPC4 TEST(+) port and the test (see Section 2.3.7.1).
If you are using a G15K or BG15K Q-RPT with a Dual Volume Unit (DVU), its location andconnections should be considered (see Section 2.3.7.2).
Support facilities required include:•An electrical power source of 100 to 240 VAC, 50 - 60 Hz.

•

A continuous, regulated pressure supply of clean, dry, non-corrosive gas at PPC4 maximum
control pressure + 10 % (70 kPa (10 psi) in the case of a BG15K Q-RPT) to be connected to the
PPC4 SUPPLY port. Lower gas pressure supply can be used but should exceed the maximum
desired test output pressure by 10 to 20 %.

•A vacuum source of less than 1 psia (7 kPa) and with displacement of at least 90 lpm (3 cfm)
if control of pressures under 3 psi (20 kPa) gauge is desired.

2.3

Setup
2.3.1

Preparing For Operation

To prepare PPC4 for check out and operation:
Remove the plastic caps from the PPC4 rear panel pressure connections.
Remove the protective plastic sheet from the front panel display.
Familiarize yourself with the front and rear panel (see Section 2.3.2).
Then proceed with Sections 2.3.3 to 2.3.10.

Page 6

2. INSTALLATION

2.3.2

Front And Rear Panels
2.3.2.1

Front Panel Ready/Not Ready indicator Controlled pressure measurement
 Display Multi-function keypad Vent Indicator Direct pressure control keys
 Cursor control keys
 Select and Enter knob
 Remote activity indicator USB connection

Figure 1. PPC4 advanced interface front panel

A

G

F

 Ready/Not Ready indicator Display Remote activity indicator Cursor control keys

B

E

C

D
 Direct pressure control keys
 Vent Indicator USB connection

Figure 2. PPC4 basic interface front panel
Page 7

PPC4™ OPERATION AND MAINTENANCE MANUAL

2.3.2.2

Rear Panel
C
D

A

B

O

N

M

 ATM port
 COM2 Connector
 Optional USB Connector
 Optional Ethernet Connector
 Optional IEEE-488 Connector
 COM1 Connector Power Switch
 Fuse

E

L K

J

F

I H G

 Electrical Power Connector (IEC-320-C13)
 Product Label Drivers (12 V) Connector
 Pressure Connection, TEST(+)
 Pressure Connection, TEST(-)
 Pressure Connection, SUPPLY Pressure Connection, EXHAUSTFigure 3. Rear panel with optional connectors

2.3.3

Power Connection

Check that the PPC4 power switch is OFF.
Connect the supplied power cable to the rear panel power module.
Connect the other end of the power cable to an electrical supply of 100 to 240 VAC,
50-60 Hz.

2.3.4

Connecting To A Pressure Supply (Supply Port)

Using a pressure connecting hose or tube of appropriate pressure rating, connect thepressure supply to the SUPPLY port on the rear panel of PPC4. The PPC4 SUPPLY port
connection is 1/8 in. NPT female.
The supply pressure should be equal to the maximum PPC4 control pressure + 10 % (or70 kPa (10 psi) for a BG15K Q-RPT). Lower gas pressure sources can be used but should
exceed the maximum desired test output pressure by 10 to 20 %.

Page 8

2. INSTALLATION Caution
Never connect a pressure supply greater than 20 % over the maximum
pressure of the PPC4 Hi Q-RPT you are using (except when the Hi Q-RPT
is a BG15K Q-RPT). Be sure to connect the pressure supply to the
SUPPLY port. Connecting to another port can damage the PPC4.

2.3.5

Connecting A Vacuum Pump (Exhaust Port)

For PPC4 to set pressures under atmosphere and/or to reliably set pressure under 20 kPa (3 psi)
gauge (other than zero gauge), a vacuum supply must be connected to the EXHAUST port.

 Caution•

Never connect a pressure supply to or plug the PPC4 EXHAUST port.

•

To avoid building up pressure on the EXHAUST port or on a vacuum
pump connected to the EXHAUST port, the vacuum source should
either be continuously ON or the EXHAUST port should be bypassed
to atmosphere when the vacuum source is OFF. This is because
when a supply pressure is applied to the PPC4 SUPPLY port and the
PPC4 is NOT in the vent ON condition, there is typically a constant gas
exhaust through the PPC4 EXHAUST port.

Note
To ensure optimum pressure control when changing the pressure applied
to the EXHAUST port from vacuum to atmosphere or vice-versa, be sure
to change the control reference setting if the setting is NOT in AUTO mode(see Section 3.2.27.1).

2.3.6

Connecting External Q-RPTS In RPM4 Reference
Pressure Monitor

PPC4 can be connected pneumatically and by RS232 to a RPM4 reference pressure monitor
to use up to two external Q-RPTs in RPM4 as external reference pressure measurement
devices (see Section 3.2.5).
The PPC4 then manages communications and other RPM4 functions to integrate the RPM4
measurement capabilities into the PPC4 system. The RPM4 Q-RPT module’s Self Defense
System (SDS) is used to shut-off RPM4 Q-RPTs from the pressurized system when they are
not in use (see the RPM4 Operation and Maintenance Manual).

Note
As a general rule, making the pneumatic connection between the PPC4TEST port and the remote Q-RPT as direct as possible favors goodpressure control. As distance, volumes and restrictions between the
PPC4 TEST port and the remote Q-RPT are added, the possibility ofdifficulty with pressure control when using the external Q-RPT increases.
To connect a PPC4 to an RPM4 to be used as part of the PPC4 system, proceed as follows:Note
Set up the RPM4 for use as an external device to PPC4 following the
instructions in the RPM4 Operation and Maintenance Manual, Using RPM4
with a PPCx Controller/Calibration Section.

Page 9

PPC4™ OPERATION AND MAINTENANCE MANUAL

Using tubing of appropriate pressure rating and a Tee, connect the RPM4 Q-RPTTEST(+) port to the PPC4 TEST(+) port. The third leg of the Tee is for the connection to
the device or system under test.

Note•

If a RPM4 Q-RPT will be used in a gauge pressure range of less than
100 kPa (15 psi), consider connecting the RPM4 Q-RPT module TEST() port to the PPC4 TEST(-) port and to the “low” connection of the UUT
if available. This will improve pressure control and stability when
ambient pressure is unstable. If the Q-RPT is an Axxx designation
Q-RPT, this connection should be made but also be left open toatmosphere.

•

When external Q-RPTs are used with PPC4, the maximum set
pressure is the maximum pressure of the PPC4 controller/calibrator.
The maximum pressure of the PPC4 is determined by the PPC4 Hi QRPT or utility sensor (see Section 1.2.1).

Using a standard pin-to-pin DB-9M to DB-9F RS232 cable, connect COM2 of the PPC4
to COM1 of the RPM4 (see Section 6.3.1.2).
Turn ON the PPC4 and RPM.
Select <RPT> in the Main Menu in the Basic interface (see Section 4.5.12) or[AutoRange], Range: from the Main Run Screen in the Advanced user interface. QRPTs with whom communication is established will be shown on the PPC4 display
identified by their position (see Table 3).

Note•

For PPC4 to identify external RPM4, the RPM4 COM1 port settingsmust be:Baud rate:
Parity:Date bits:
Stop bits:•

between 1200 and 19200
Even
7
1

If PPC4 is not able to establish communications with an RPM4 and its
Q-RPTs, check that the RPM4 COM1 port settings conform to therequirements above. If the COM1 port settings are correct, check thatthe correct communications cable is being used (standard pin-to-pin
DB-9M to DB-9F RS232) and is connected to the correctcommunications ports.
PPC4 COM2 > RPM4 COM1

•

2.3.7

See the RPM4 Operation and Maintenance Manual for additional
information on RPM4 RS232 communications and COM port settings.

Connecting To The Device Under Test (Test(+) And
Test(-) Ports)

If you are using a self purging liquid trap (SPLT), see Section 2.3.7.1 before proceeding toconnect the device under test.
If the PPC4 has a G15K or BG15K Q-RPT, a dual volume unit (DVU) should be installed for very
low pressure control. See Section 2.3.2.2 before proceeding to connect to the device under test.
Using a pressure connecting hose or tube of appropriate pressure rating, connect the device orsystem to be tested to the PPC4 TEST(+) port. The PPC4 TEST(+) connection is 1/8 in. NPT female.

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2. INSTALLATION

PPC4 TEST(+) AND TEST(-) PORTS
All PPC4s have a TEST(+) and a TEST(-) port. See Figure 32 for PPC4 internal Q-RPTTEST port configurations.
The TEST(+) port is connected to Axxx (absolute) Q-RPTs and to the high side of Gxxx or
BGxxx (gauge, bi-directional gauge) Q-RPTs.
The TEST(-) port is connected to PPC4s internal barometer, if present, and to the low side ofGxxx or BGxxx (gauge, bi-directional gauge) Q-RPTs.
•

When operating in absolute mode: The TEST(-) port is left open to atmosphere.

•

When operating in gauge or negative gauge mode with a range greater than 50 kPa(7.5 psi): The TEST(-) port is normally left open to atmosphere. A possible exception iswhen the device or system under test is in an ambient pressure that may differ significantly
from the ambient pressure around the PPC4. For example, if the PPC4 is controllingpressure into UUTs in an environmental chamber, the pressure in the environmental
chamber may be different from ambient pressure around the PPC4. In this case,connecting a tube from the TEST(-) port to the inside of the chamber may improvemeasurement results. If the Q-RPT in use is an Axxx Q-RPT, this tube must be left open to
the environment so that the pressure inside cannot deviate too far from ambient. When using
an Axxx Q-RPT, if this tube is connected to the low or reference side of UUTs, be sure toopen to the local environment as well.

•

When operating in gauge or negative gauge mode with a range less than 50 kPa (7.5 psi):
As a general rule, it is preferable to connect the PPC4 TEST(-) port(s) directly to the low orreference side of the device under test to ensure that these are at the same pressure.
When using an Axxx Q-RPT, this connection must also be open to atmosphere. When usinga Gxxx or BGxxx Q-RPT, it is preferable that this connection not be open to atmosphere.

 Caution•

Do not apply pressure to the TEST(+) port without having a pressure
supply equal to or greater than the applied pressure connected to the
SUPPLY port. When controlling pressure to the TEST(+) port
externally, do not cause the pressure to change at a rapid rate. For
example, do not vent suddenly by opening an external valve. Internal
damage to the PPC4 may result.

•

Do not connect a pressure supply to the TEST(-) port. The pressure
applied to this port should be maintained at atmospheric pressure,
between 70 and 110 kPa (10 and 16 psia). Exceeding these limits may
damage a Gxxx or BGxxx Q-RPT and/or the PPC4’s on-board
barometer.

•

Operating the PPC4 connected to a system with liquid contaminants
without taking proper precautions to purge the system and test line
may cause contamination of the PPC4 that will require non-warranty
service.

Note•

Minimizing the length of the test connection tubing will enhancecontrol performance and reduce pressure setting time. For normal
operation, the total volume of the device or system under test
including connecting tubing should be less than 1 000 cc (60 in3) up
to 2 000 kPa (300 psi) and less than 500 cc (30 in3) above 2 000 kPa(300 psi).

•

PPC4 pressure control will not operate properly if there are excessive
leaks in the test system. In general, the maximum acceptable leak rate
for optimal PPC4 automated pressure control operation and to ensure
in tolerance measurements with default pressure control parameters
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PPC4™ OPERATION AND MAINTENANCE MANUAL

is ± 0.5 % of set pressure/minute. In DYNAMIC CONTROL mode, tohandle higher test system leak rates, increase the hold limit using
CUSTOM CONTROL (see Section 3.2.13).
•

PPC4 pressure control may be adversely affected if the test
connection tubing is too restrictive. For optimum results, the innerdiameter of the connecting hose should be at least 1.75 mm (0.07 in.).

2.3.7.1

Installing a Self Purging Liquid Trap (SPLT)The SPLT (optional) is intended to collect and exhaust liquid or othercontaminants that may be present in the device or system under test so that they
do not return to contaminate the PPC4.
The SPLT is installed in the TEST(+) connection line at a low point between
PPC4 and the device or system under test. If the PPC4 system includes external
Q-RPTs in an RPM4, the RPM4 should be connected on the PPC4 side of the
SPLT.
See the SPLT Operation and Maintenance manual for more complete
instructions on SPLT installation.

2.3.7.2

Installing a Dual Volume Unit (DVU), G15K and
BG15K Q-RPTS

To achieve in tolerance pressure control with the very low range of the G15K and
BG15K Q-RPTs, a PK-PPC-BG-DVU dual volume unit should be installed in-lineon the TEST(+) and TEST(-) ports. The DVU includes two thermally isolated
volumes installed in the test line to improve control stability.
See the PK-PPC-BG-DVU instruction sheet for additional information on its
installation.

2.3.8

The ATM Port

The PPC4 ATM port is the system vent to atmosphere point used to set zero gauge pressure aswell as to obtain Q-RPT measurements of atmospheric pressure. Though a pressure hose
can be connected to the ATM port to direct the vented gas flow, a completely unobstructedconnection to atmosphere must be maintained for PPC4 reference pressure measurements
to operate normally.
The PPC4 ATM port fitting is 10-32 UNF.

 Caution
NEVER plug, obstruct or connect a supply pressure to the PPC4 ATM
port. This may adversely affect GAUGE mode operation and AutoZeroing
functions.

2.3.9

Check/Set Security Level

PPC4 has a security system based on user levels. By default, the security system is set to“low”, which includes certain access restrictions, and there is no password required tochange the security level. See Section 3.2.26.4 for information on the security level system.
As part of the PPC4 startup, determine the security level that is appropriate for the PPC4 andset a password if desired.

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2. INSTALLATION Caution
PPC4 is delivered with the security level set to “low” to avoid inadvertent
altering of critical internal settings but with access to changing security
levels unrestricted. It is recommended that the low security level bemaintained at all times and password protection be implemented if control
over setting of security levels is desired.

2.3.10Turn Off Absolute And Negative Gauge Mode
(AXXX RPT)

If your PPC4 has an Axxx (absolute) Q-RPT, it is able to operate in gauge, negative gauge
and absolute measurement modes (see Section 3.2.11). If the PPC4 will be used only ingauge mode, the other measurement modes can be turned off so they are no longer
accessible. This can avoid confusion and/or accidental use of the wrong measurement mode.
See Section 7.2.5 for complete information on turning off absolute and negative gaugemeasurement modes.

2.4

Power-Up And Verification
2.4.1

Switch Power On

Actuate the power switch on the PPC4 rear panel. Observe the front panel display as PPC4
initializes error checks and goes to the Main Run Screen (see Sections 4.1 and 5.1).
PPC4 power-up condition is Internal, Hi Q-RPT or utility sensor active, VENT ON unless thepressure measured by the Hi Q-RPT is more than 20 kPa (3 psi) away from standard
atmospheric pressure.
If the PPC4 fails to reach the Main Run Screen, service is required. Record the sequence of
operations and displays observed.

2.4.2

Check Pressure Measurement Operation
2.4.2.1

Checking Absolute Mode Pressure Measurement

If the PPC4 is not vented (VENT LED OFF),  to vent the PPC4 (VENT LED
ON) (see Section 3.2.14) and wait for a Ready indication (see Section 3.2.3).

2.4.2.1.1

Basic Interface

Select <Range> in the Main Menu to change ranges if necessary and select the
Axxx (absolute) Q-RPT DF range (see Section 4.4.1). Press <Mode> in the Main
Menu and select <Absolute> mode (see Section 3.2.11). Use <Unit> under theMain Menu to change the pressure unit if desired (see Section 3.2.10).
Observe the current value of atmospheric pressure. Check that the value agrees
with the local value of atmospheric pressure. Repeat this process for all the
Axxx (absolute) Q-RPTs and or the utility sensor in the PPC4 system. Check
that the values of atmospheric pressure measured by the different devices agreewith each other within PPC4 or RPM4 measurement tolerances as applicable(see Section 1.2.3). If they do not agree within tolerances, the PPC4 or RPM4
Q-RPT may need calibration or repair.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

2.4.2.1.2

Advanced Interface

Use [AutoRange], Range: to select the DF range of the Axxx (absolute) Q-RPT(see Section 5.7.1). Enter (click) the measurement mode shortcut (see Sections
5.1 and 5.7.6.2) to change to Absolute mode. Enter the unit shortcut (seeSections 5.6.1 and 5.7.6.1) to change the pressure unit if desired.
Observe the current value of atmospheric pressure. Check that the value agrees
with the local value of atmospheric pressure. Repeat this process for all the
Axxx (absolute) Q-RPTs and or the utility sensor in the PPC4 system. Check
that the values of atmospheric pressure measured by the different devices agreewith each other within PPC4 or RPM4 measurement tolerances as applicable(see Section 1.2.3). If they do not agree within tolerances, the PPC4 or RPM4
Q-RPT may need calibration or repair.

2.4.2.2

Checking Gauge Mode Pressure Measurement

If the PPC4 is not vented,  to vent it (see Section 3.2.14).

Note
It is normal for PPC4 to indicate a value other than zero whenvented when gauge mode is first entered or ranges arechanged. After about ten seconds, the vent LED should flash
and zero should be indicated. If this does not occur, check that
the AutoZero function is ON (see Section 3.2.22). If AutoZero is
ON and the displayed pressure will not zero when vented in gaugeor bi-directional gauge measurement mode, PPC4 may need repair.

2.4.2.2.1

Basic Interface

Select <Range> in the Main Menu to change ranges if necessary and select the
Axxx (absolute) Q-RPT DF range (see Section 4.4.1). Press <Mode> in the Main
Menu and select <Gauge> mode (see Section 3.2.11). Use <Unit> under theMain Menu to change the pressure unit if desired (see Section 3.2.10).
Observe that, within ten seconds, zero is indicated. It is normal for PPC4 to indicate
a value other than zero for up to ten seconds when first entering gauge mode.
Select <Range> under the Main Menu to change ranges, observe that zero isindicated for each Q-RPT within 10 seconds.

2.4.2.2.2

Advanced Interface

Use [AutoRange], Range: to select the DF range of the Axxx (absolute) Q-RPT(see Section 5.7.1). Enter (click) the measurement mode shortcut (see Sections
5.1 and 5.7.6.2) to change to Absolute mode. Enter the unit shortcut (seeSections 5.6.1 and 5.7.6.1) to change the pressure unit if desired.
Observe that, within ten seconds, zero pressure is indicated. It is normal for PPC4
to indicate a value other than zero for up to ten seconds when first enteringgauge mode.
Use [AutoRange], Range: to change ranges, observe that zero pressure isindicated for each Q-RPT within 10 seconds.

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2. INSTALLATION

2.4.3

Leak Test

If desired, perform a leak check of the test system (see Section 3.2.18).

2.4.4

Purge

If an SPLT is included and installed in the test line (see Section 2.3.7.1) and the Device Under Test
(UUT) may be contaminated with liquids, perform a purge of the UUT (see Section 3.2.27.4).
The Purge function must first be enabled (see Section 4.5.7.4 for Basic Interface and Section
5.7.12.3 for Advanced Interface). This will rid the UUT of contaminating liquids.

 Caution
Operating the PPC4 connected to a system with liquid contaminants
without taking proper precautions to purge the system and test line may
cause contamination of the PPC4 that will require non-warranty service.

2.4.5

Check Pressure Control Operation
2.4.5.1

Basic Interface

Select a pressure range using in the Main Menu <Range> selection (see Section
4.4.1).
In the Main Menu press <Setup>, <Control>, <Dynamic> (see Section 3.2.2.1).
 to return to the Main Run Screen.
, key in a target(see Section 4.2.1).

2.4.5.2

pressure

withintheactive

range

and

.

Advanced Interface

Select a pressure range using [AutoRange], Range: (see Section 5.7.1).
Select dynamic control mode with the control mode shortcut (see 5.6.1 andSection 5.7.8.2).  to return to the Main Run Screen.
, key in a target(see Section 5.5.1).

pressure

withintheactive

range

and

.

 Caution
Verify the maximum pressure rating of the system connected to the PPC4TEST(+) port before entering a target pressure. Do not enter a target
pressure greater than the pressure rating of the system connected to the
PPC4 TEST(+) port.
PPC4 should set the target pressure and indicate Ready (see Section 3.2.3) continuously in
15 to 60 seconds. If it does not, see Section 8 to troubleshoot.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

2.5

Short Term Storage

The following procedure is recommended for short term storage of PPC4:
Vent the PPC4 test pressure.
Turn the power OFF using the rear panel power switch.
Shut OFF or disconnect the pressure supply.
Shut OFF or disconnect the vacuum supply. Be sure the pressure supply is disconnected or thevacuum pump is bypassed from the PPC4 EXHAUST port before turning OFF the vacuum pump.

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3. OPERATING PRINCIPLES

3.

Operating Principles

3.1

User Interfaces

PPC4 is designed with two front panel local interface configurations. The Advanced Graphical User
Interface version, PPC4-ui, is typically used for bench top operation. The limited function Basic Interface
with the basic PPC4 is typically used for computer controlled applications such as automated calibration.
See Section 4 for operation information on the Basic Interface. See Section 5 for operation informationon the Advanced Interface.
Remote communication is by RS232 (COM1), IEEE-488, Ethernet or USB. See Section 6 for specificinformation on remote communication.
Every PPC4 ships with PPC4 Cockpit software as well. PPC4 Cockpit communicates with the PPC4 by
RS232, Ethernet, IEEE-488 or USB. PPC4 Cockpit duplicates the functionality, look and feel of theadvanced user interface and provides functionality and an easy to use interface for users of both basic
PPC4 and PPC4-ui (see Section 6.2).

3.2

General Operating Principles
3.2.1

Direct Pressure Control

 PURPOSE
The direct pressure control keys provide direct manual control to increase, decrease, and jog
the PPC4 pressure.
 OPERATION
 or  ( or  for the Basic Interface) cause pressure to increase or decrease at the fast
slew rate.
 or  when dynamic control is not active cause pressure to increase or decrease at theslow slew rate.
 or  during dynamic control causes the pressure to jog or step by a fixed amount.
During active pressure control, they cause the target pressure to be changed by the fixedamount. One press causes one step. The approximate value of the step is set automaticallydepending on the current active PPC4 range. The value can be adjusted with the Jog function(see Section 3.2.19).

 Caution
The fast direct pressure control keys,  and , interrupt andoverride automated pressure control.

3.2.2

Automated Pressure Control

PPC4 automated pressure control provides automated adjustment and control of pressure toa user designated target value.  from the Main Run Screen allows a pressure control
target value to be entered and executed.  or  cause active pressure control to beinterrupted. Sending a remote command when in local mode also interrupts pressure control.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

PPC4 supports two pressure control modes to meet different pressure setting and controlling
requirements: dynamic and static. Pressure control parameters for each control mode areautomatically set to optimal default values for the operating PPC4 range when the range isselected or AutoRange is used (see Section 3.2.8). Control parameters can be customized
using screen selections (see Section 4.4.5.1 for Basic Interface and Section Section 5.7.8.2.1
for Advanced Interface selections).
Control parameters:
Target Pressure

The pressure set point specified by the operator.

Hold Limit

A symmetrical positive and negative limit around the target value within
which the controlled pressure is maintained.

Stability Limit

A rate of change of pressure limit in units of pressure/second used as acriterion for the Ready/Not Ready condition in static control or when
PPC4 is idle (control not active).

Note
See Sections 3.2.2.1 and 3.2.2.2 (Dynamic Control and Static Control) for a
detailed explanation of each control mode and its advantages, the default
control parameters and the control customization options.

3.2.2.1

Dynamic Control

Dynamic control mode is designed to set the pressure to the target value andcontrol continuously to keep pressure within the hold limit and as close to thetarget value as possible (see Figure 4) The advantage of this control mode isthat the final pressure achieved is the same as the target value. The maximum
value of the control error is equal to the hold limit. The average value of thecontrol error is typically much smaller than the hold limit.
During dynamic pressure control, the hold limit is active. If the pressure goesoutside of the hold limit, a Not Ready condition occurs. See Table 5 and Table 6
for default hold limit values. To customize the hold limit see Section 4.4.5.1 for
Basic Interface and Section 5.7.8.2.1 for Advanced Interface.

Figure 4. Dynamic Pressure Control Operation

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3. OPERATING PRINCIPLES

3.2.2.2

Static Control

Static control mode is designed to set the pressure near the target value andthen interrupt active control to allow pressure to stabilize naturally within the holdlimit. The advantage of this control mode is that pressure can be set and/or
measured within a defined limit of a target without interference from the pressure
control system. In a system without excessive leaks, the pressure stability
achieved may be greater than the stability with which the pressure control
system can actively control pressure. Using static control to control pressurenear the desired set point and then measuring back the stabilized pressure
without interference of the control function can allow control errors to becompletely eliminated. However, the final pressure achieved is not equal to thetarget value.
During static pressure control, the hold limit is active. If the pressure goes outside of thehold limit, a Not Ready condition occurs (see Section 3.2.3) and pressure isreadjusted to the target value (see Figure 5). For default values for hold andstability limits, see Table 5 and Table 6. To customize the hold and stability limits
see Section 4.4.5.1 for Basic Interface and Section 5.7.8.2.1 for Advanced
Interface.

Figure 5. Static Pressure Control Operation

3.2.3

Pressure Ready/Not Ready

There is a Ready/Not Ready indicator on the PPC4 front panel. This indication is intended toprovide the user with a clear and objective criterion for determining when a valid pressure
measurement can be made.
The Ready/Not Ready LED indications are:<Green>Pressure Ready. PPC4 is either actively controlling the pressure andthe criteria for a Ready condition to occur have been met or PPC4 is NOT
actively controlling the pressure and the rate of change of pressure
is within the stability limit.

<Yellow>(Advanced Interface Only) Pressure Near Ready. PPC4 is actively
controlling the pressure using fine pressure control and is close tomeeting the criteria for a Ready condition.

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PPC4™ OPERATION AND MAINTENANCE MANUAL<Red >

Pressure Not Ready. Either PPC4 is idle and pressure does not meetthe stability test or PPC4 is actively controlling the pressure and Readyconditions have not yet been met.

When pressure control is NOT active: A Ready condition occurs any time NO control
valve is operating and the pressure rate of change is inside the stability limit. The stability
limit is defined in terms of rate of change of pressure in current pressure units per second.
When pressure control is active: The criteria for determining the Ready/Not Readycondition depend on whether the current control mode is static or dynamic. Pressure
Ready/Not Ready parameters are set by default when AutoRange is used, or a control modeis selected. The parameters can be customized if desired (see Section 4.4.5.1 for Basic
Interface and Section 5.7.8.2.1 for Advanced Interface).
Dynamic Control Ready/Not Ready
With dynamic pressure control active, a Ready condition occurs whenever:•The current measured pressure is inside the hold limit.

Note
In dynamic control mode, it is common to assume that when a Readycondition occurs (pressure inside the control hold limit), the measured
pressure equals the target pressure. For this reason, when the pressure
is Ready in dynamic control mode, the measured pressure display is equal
to the target pressure.

Figure 6. Ready/Not Ready in Dynamic Pressure Control Mode

Static Control Ready/Not Ready
With static pressure control active a Ready condition occurs whenever:•NO control valve is operating.

•

The current measured pressure is at the target value within the hold limit.

•

The rate of change of pressure is less than the current stability limit.

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3. OPERATING PRINCIPLES

Figure 7. Ready/Not Ready in Static Control Mode

Ready/Not Ready When Not Actively Controlling
When NO automated pressure control is active, Ready is indicated whenever the rate of changeof pressure is less than the current stability limit (see Section 4.4.5.1 for Basic Interface andSection 5.7.8.2.1 for Advanced Interface).

3.2.4

Gauge and Negative Gauge Modes with an Axxx
(Absolute) Q-RPT, Dynamic Compensation for
Atmospheric Pressure

Q-RPTs with the designation Axxx are intrinsically absolute but they are also used in gauge andnegative gauge measurement modes (difference from atmosphere) (see Section 3.2.11). Gauge
measurement mode is achieved by subtracting the value of atmospheric pressure, Poffset,G, fromthe Q-RPT’s absolute reading using AutoZero (AutoZ, see Section 3.2.22). In gauge ornegative gauge measurement mode, the AutoZ routine that measures Poffset,G, is run
automatically whenever the PPC4 is in the vented condition. This ensures the continuous
automated updating of the Poffset,G value corresponding to atmospheric pressure. Gaugepressure is the measured absolute pressure, Pu, minus the atmospheric offset.
Pgauge = Pu - Poffset,GHowever, atmospheric pressure can change between opportunities to run AutoZ and update
the value of Poffset,G, for example when running an extended test without venting. PPC4 uses
dynamic compensation of atmospheric pressure to correct for these changes inatmospheric pressure. When AutoZ executes, and Poffset,G is determined, the reading of
PPC4’s on board barometer, Patm,0, is also recorded. Later, when no longer vented, thechange in atmospheric pressure, ∆Patm since Poffset,G was updated is the difference between
the current barometer reading, Patm, and the barometer reading at the time of AutoZ
execution, Patm,0:∆Patm = Patm - Patm,0Dynamic compensation for atmospheric pressure uses ∆Patm to correct the value of Poffset,G,thus always compensating real time for changes in atmospheric pressure:Pgauge = Pu - Poffset,G - ∆Patm
Gauge pressure measurement on an Axxx (absolute) Q-RPT allows instantaneous switching
between gauge and absolute measurements modes. Any additional uncertainty in gaugepressure mode due to the dynamic compensation for atmospheric pressure technique is a
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PPC4™ OPERATION AND MAINTENANCE MANUAL

function of the resolution and short term stability of the on-board barometer rather than its
absolute measurement uncertainty. This additional uncertainty is ± 1 Pa (0.00015 psi).

3.2.5

Multiple Internal and External Q-RPTs

A base PPC4 pressure controller includes a high precision, utility pressure sensor whose
range is equal to the controller’s range. The utility sensor is not intended to serve as apressure reference for low uncertainty measurement. It is for indication, pressure control,
system safety and maintenance functions only.
To obtain low uncertainty, traceable pressure measurement, PPC4 uses Quartz Reference
Pressure Transducers (Q-RPT). Up to four Q-RPTs can be included in a PPC4 pressure
controller/calibrator system. One or two Q-RPTs can be built into the PPC4, up to two may belocated outside the PPC4 enclosure, in an RPM4 reference pressure monitor (one or two in theRPM4). Once the Q-RPTs available to a PPC4 system have been set up and identified, theiruse is managed by PPC4 transparently to the operator.
The use of multiple Q-RPTs, combined with PPC4’s infinite ranging capability and
AutoRange feature (see Section 2.3.7), make it possible for a single PPC4 pressure
controller/calibrator system to cover an extremely wide range of test ranges andmeasurement modes with low uncertainty in each range.
Communication between an external RPM4 and a PPC4 controller is by RS232 connection
from PPC4’s COM2 port. One common pressure connection can be made between the
PPC4 and RPM4 pressure ports (see Section 2.3.6 for information on setting up a PPC4 withexternal RPM4). RPM4 Q-RPT modules’ SDS function protects RPM4 Q-RPTs fromoverpressure when they are not in use.
The PPC4 RPT function (see Section 4.5.12 for Basic Interface and Section 5.7.1, RPT
Search, for Advanced Interface) is used to identify Q-RPTs available to the PPC4. The PPC4
then manages the internal and external Q-RPTs transparently to the operator, selecting theappropriate Q-RPT for the range of operation and operating valves to connect anddisconnect them as needed.
Each Q-RPT has a default range, which is its maximum range. It can also be downranged
using PPC4’s AutoRange function.
The PPC4 internal pneumatic layout for handling its utility sensor and one or two Q-RPTs
depends on the number of Q-RPTs and their type (Axxx absolute, Gxxx gauge, BGxxx bidirectional gauge). Figure 32 provides pneumatic schematics of the different PPC4 internal
utility sensor and Q-RPT configurations with a chart of valve status for various operating conditions.

 Caution•

Before operating PPC4 with external Q-RPTs, check carefully that the
RPM4’s Q-RPT TEST(+) port(s) is/are connected to the PPC4 TEST(+)
port. If an external Q-RPT is NOT connected to the PPC4 TEST(+)
port, it will NOT measure the pressure generated by PPC4 and PPC4
may reach a pressure higher than the target pressure before its
watchdog function recognizes that the external Q-RPT is notconnected (see Section 3.2.21.1). The PPC4 watchdog function
monitors differences in the change in pressure indicated by an active,
external Q-RPT and the PPC4 Hi utility sensor or Q-RPT (watchdog). If
the difference becomes excessive, control is aborted, an audible
warning sounds and a warning is displayed. If this occurs, make surethe PPC4 and RPM4 Q-RPT TEST(+) ports are connected together andtry again.

•

RPM4 with Q-RPT full scale spans below 14 MPa have SDS self
defense system to isolate and protect the Q-RPTs. If an external
RPM4 SDS pressure rating is less than the PPC4 maximum pressurethen a warning will be displayed on the PPC4 front panel when the
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3. OPERATING PRINCIPLES

RPM4 is detected. In addition, AutoRanged ranges greater than the
SDS rating are not allowed (see Sections 6.5.4, 3.2.8). In order tocreate AutoRanged ranges or generate pressures above the SDS
pressure rating the RPM4 must be disconnected or the RPM4 SDS
must be upgraded to a higher pressure rating. Upgrades may be doneat the DH Instruments service center (see Table 36).
Position Identification of Q-RPTs In a PPC4 System
Position identification of the currently active Q-RPT or utility sensor in the PPC4 system iscontinuously displayed in the upper right hand corner of the Basic Interface Main Run Screen
and most other screens. Position identification of the currently active Q-RPT or utility sensor isdisplayed by selecting [AutoRange] and viewing the RPT: field in the Advanced Interface. See
Table 3 for position designation protocol for the Q-RPTs available in a PPC4 system.
See Table 1 for a complete listing of Q-RPTs available and their default ranges.
Table 3. Position Designators of Q-RPTs in a PPC4 System
Q-RPT POSITIONIDENTIFICATIONDISPLAY SYMBOL*

Internal to PPC4, utility sensor, if present

Internal Utility, Hi

IuH

Internal to PPC4, Q-RPT of maximum
rangeInternal Hi

IH

Internal to PPC4, Q-RPT with lower
maximum range in PPC4 with two
Q-RPTs or a utility sensor and Q-RPT.

Internal LoIL

External to PPC4, Q-RPT of higher
maximum range in RPM4, if present

External Hi

X1HExternal to PPC4, Q-RPT with lower
maximum range in dual Q-RPT RPM4, if
present

External Lo

X1L* The display symbol is included in the upper, right hand corner of most Basic Interface displays/menus and infields in AutoRange screens in the Advanced Interface.

3.2.6

Multiple Ranges (Q-RPTs, AutoRange and Infinite
Ranging)

A PPC4 range is defined as a pressure span and associated settings.
A PPC4 may have multiple ranges. Each Q-RPT (and the utility sensor, if present) available to the
PPC4 system has a default range which is its maximum span. Additional ranges, lower than the
Q-RPT’s maximum span, may be created using AutoRange (see Section 3.2.8). Ranges
created using AutoRange may be saved with all their settings for reactivation later (see Section
5.7.1 for the Advanced Interface and Section 4.4.1.1 for the Basic Interface).
Most settings made in a PPC4 range, such as unit of measure, measurement mode, display
resolution, control mode and control parameters are specific to the range. Many settings
made while a range is active apply to that range and not other ranges. The range specificsettings are stored with the range and recalled whenever the range is made active. This makes
setting up and saving ranges a convenient way to store and recall frequently used operating
configurations. See Table 4 for a listing of PPC4 adjustments and settings and whether they
are range, Q-RPT or system specific.
The ranges available on a PPC4 system may be queried (Range) and/or created(AutoRange) with functions available locally. External Q-RPTs connected to the PPC4 may
be initialized with RPT Search. For the Advanced interface see Sections 5.7.1. For the
Basic Interface see Sections 4.5.14, 4.5.10 and 4.5.12.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Table 4. Settings and What They Are Specific To (Range, Measurement Mode, Q-RPT, System)
SETTINGPURPOSESPECIFIC TOSECTION

Unit

Set pressure unit of measureRange

3.2.10Mode

Set pressure measurement mode
(absolute, gauge, negative gauge)

Range

3.2.11

Resolution

Set pressure display resolution

Range

3.2.19Jog

Set jog step size

Range

3.2.20Control

Set pressure control mode andparametersRange

3.2.13Upper Limit

Set upper and lower pressure limit alarm

Range and measurement mode

3.2.21AutoZ

Run AutoZ, ON/OFF, set and view value

Range and measurement mode

3.2.22

Screen Saver,Sound, Time,
ID, Level

Set system user preferences

System

3.2.26

Head

Set fluid head correction height, fluid,
unit of measure

System

3.2.16

Control
reference

Set EXHAUST port pressure condition

System

3.2.27.1

Purge

Enable/disable purge function

System

3.2.17

Valve Drivers

Set status of external valve drivers

System

3.2.23TEST (-) Vent

Set status of TEST(-) vent valve,
if present

System

3.2.27.5

Calibration

Various Q-RPT and utility sensor
calibration functions

Q-RPT, utility sensor or barometer

7.2,
7.4

3.2.7

7.3,

Operation with a PG7000 Piston Gauge

PPC4 can act as a pressure control source to automated setting pressure and floating thepiston of a PG7000 gas operated piston gauge.
For automated operation, the PPC4 communicates with the PG7000 through an RS232
connection from the PG7000 COM3 port to the PPC4 COM1 port. Pressure control
commands are sent from the PG7000 when it is in “AutoGen” mode (see the PG7000
Operation and Maintenance Manual).
The PPC4 may also be operated manually using its direct pressure control keys (see Section 3.2.1).

3.2.8

AutoRange PURPOSE
To automatically set up PPC4 to optimize its measurement and control characteristics andfeatures to cover a specific pressure range. AutoRange functions create new ranges or selectfrom existing saved ranges.
 PRINCIPLE
PPC4 is designed to support the calibration and test of a very wide variety of test ranges invarious measurement modes with a single pressure controller system.
The AutoRange function simplifies the task of selecting the Q-RPT best suited to cover a
specific test range and setting controller parameters appropriately for the range. These are
set automatically based on operator entry of desired measurement mode, pressure unit ofmeasure and range full scale. The selections and default settings made by AutoRange aresummarized in Table 5.

Page 24

3. OPERATING PRINCIPLESTable 5. Settings Made by AutoRange
SETTING/SELECTIONPURPOSESET TOSECTION

Unit

Set pressure unit of measure

Operator specified during
AutoRange

3.2.10Mode

Set pressure measurement mode
(absolute, gauge, negative gauge)

Operator specified during
AutoRange

3.2.11

Full scale

Establish span maximum

Operator specified during
AutoRange

None

AutoRanged span

Basis of span based setting
calculations

Absolute mode: Zero absolute tofull scale

None

Gauge mode: Zero gauge to full
scale
Negative gauge mode: Minus
atmosphere to full scale(negative equivalent of full scale
on BGxxx Q-RPT).
Q-RPT

Upper Limit
Lower Limit

Select most appropriate Q-RPT
to cover range and mode andoperate PPC4 and RPM4
internal valving to connect the
selected Q-RPT to the TEST
port(s) and shut off other QRPTs in the system

Absolute and negative gauge
mode: Axxx Q-PRT with lowest
default full scale that is greaterthan the AutoRange full scale

Set maximum and minimumpressure control target limits

Upper limit: 105 % of operator
entered full scale pressure

None

Gauge mode: Q-RPT with lowest
span whose full scale is greaterthan AutoRange full scale, Gxxx
over Axxx if spans are equal.
3.2.21

Lower limit: None in absolutemode, zero in gauge mode,
minus atmosphere in negative
gauge mode, minus equivalent ofupper limit in negative gauge
mode on a BGxxx Q-RPT.
Resolution

Set pressure display resolution

10 ppm of AutoRanged span or 1
ppm of default Q-RPT range,
whichever is larger.

3.2.19Control Mode

Select dynamic or static pressure
control

Dynamic control

3.2.2

Control Parameters

Set dynamic and static control
Ready/Not Ready control limits

Dynamic control hold limit:± 50 ppm of AutoRanged span,
5 ppm of Q-RPT span or
0.4 ppm of controller full scale,
whichever is greater

3.2.2
3.2.3

Dynamic and static control
stability limit: 50 ppm of
AutoRanged span or 2 ppm of
Q-RPT span per second,whichever is greater
Static control hold limit: 1 % of
AutoRanged span
Jog Step

Set jog step size

100 ppm of AutoRanged span

3.2.20

Q-RPT turn down

Turn down Q-RPT
characterization to improvemeasurement uncertainty whenspan is reduced

See Premium Q-RPT pressure
measurement specifications

1.2.2.1(Premium class Q-RPTs only)

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Note•

AutoRanged ranges cannot have altitude units (ft, m)•

If an external Q-RPT that should be available is not being selected by
AutoRange, search for Q-RPTs using use [AutoRange], [RPT Search]in the Advanced Interface or <RPT> in Basic Interface. Determine
whether external Q-RPTs have been properly connected and initialized(see Section 3.2.5).

•

See Table 1 for a listing of Q-RPT designators and their corresponding
default ranges and Table 3 for information on Q-RPT system position
identification designators.

•

For PPC4 to successfully identify and initialize external RPM4s, theRPM4 COM1 port settings must be:
Baud rate:
Parity:Date bits:
Stop bits:•

between 1,200 and 19,200
Even
7
1

If PPC4 is not able to establish communications with RPM4s and their
Q-RPTs, check that the RPM4 COM1 port setting conform to therequirements above. If the COM1 port settings are correct, check thatthe correct communications cable is being used (standard pin-to-pin
DB-9M to DB-9F RS232) and is connected to the correctcommunications ports.
PPC4 COM2 > RPM4 COM1•

See the RPM4 Operation and Maintenance Manual for additional
information on RPM4 RS232 communications and COM port settings.

•

When an RPM4 is initialized as an external device to a PPC4 pressure
controller, the RPM4 front panel keypad is locked out and the secondline of the display becomes:<PPC EXT DEV: IDLE> (if RPM4 is initialized by PPC4 but not
currently in use)
<PPC EXT DEV: ACTIVE> (if RPM4 is initialized by PPC4 and iscurrently in use)•

After using an RPM4 as an external device for a PPC4, cycle power toreturn to the previous RPM4 settings, restore front keypad capability
and return to the normal Main Run Screen.

•

The PPC4 utility sensor (IuH) cannot be AutoRanged.

•

The BA100K Q-RPT cannot be AutoRanged.

 Caution•

Before operating PPC4 with external Q-RPTs, check carefully that the
Q-RPT TEST(+) ports are connected to the PPC4 TEST(+) port. If theexternal Q-RPTs are NOT connected to the PPC4 TEST(+) port, they
will not measure the pressure generated by PPC4 and PPC4 mayreach a pressure higher than the target pressure before its watchdog
function recognizes that the external RPT is not connected.

•

RPM4 with Q-RPT full scale spans below 14 MPa have SDS self
defense system to isolate and protect the Q-RPTs. If an external
RPM4 SDS pressure rating is less than the PPC4 maximum pressurethen a warning will be displayed on the PPC4 front panel when the
RPM4 is detected. In addition, AutoRanged ranges greater than the
SDS rating are not allowed (see Sections 3.2.5, 6.5.43.2.8). In order toPage 26

3. OPERATING PRINCIPLES

create AutoRanged ranges or generate pressures above the SDS
pressure rating the RPM4 must be disconnected or the RPM4 SDS
must be upgraded to a higher pressure rating. Upgrades may be doneat the DH Instruments service center (see Table 36).
 OPERATIONFor Basic Interface see Section 4.5.10.
For Advanced Interface see Section 5.7.1.

3.2.9

Range

 PURPOSE
To view and/or change the active pressure measurement range and associated settings.

Note
Range selects from existing ranges in the Basic Interface and saves
current AutoRanged Ranges. See AutoRange to create ranges (seeSection 3.2.8) or to select Ranges in the Advanced Interface (see Section
5.7.1).
 PRINCIPLEA PPC4 range is defined as a pressure span and associated settings (see Section 3.2.8).
A PPC4 may have multiple ranges. Each Q-RPT (and the utility sensor if present) available
to the PPC4 system has a default range which is its maximum full scale. Additional ranges,
lower than the Q-RPT’s full scale, may also be created using AutoRange (see Section 3.2.8).
Ranges created using AutoRange may be saved with all their settings for reactivation (seeSection 5.7.1 for the Advanced Interface and Section 4.4.1.1 for the Basic Interface).
Range allows the available PPC4 pressure ranges to be viewed and selected, including
automated switching of both internal and external Q-RPTs when necessary.

Note•

Range full scale limits are given in the pressure unit that is currently
active for that range. Change the active unit to display the range limits
in a different unit.

•

Many PPC4 settings and functions are range specific. See Table 4 for
identification of range specific settings.

•

To protect against overpressure situations and for maximum
measurement performance, the active range can only be changed
when the system is vented. When prompted by the PPC4,  causes
PPC4 to vent and then complete the range change.

•

Before operating PPC4 with external Q-RPTs, check carefully that theexternal Q-RPT TEST(+) port is connected to the PPC4 TEST(+) port.
If the external Q-RPT is NOT connected to the PPC4 TEST(+) port, it
will not measure the pressure generated by PPC4 and PPC4 mayreach a pressure higher than the target pressure before its watchdog
function recognizes that the external Q-RPT is not connected.

3.2.10Unit

 PURPOSE
To select the unit of pressure in which PPC4 displays pressure values.

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PPC4™ OPERATION AND MAINTENANCE MANUALNote
For information on selecting the measurement mode (absolute, gauge,
negative gauge), see Section 3.2.11.
 PRINCIPLE
PPC4 allows the unit of measure in which pressure values are displayed to be changed. PPC4
supports 18 predefined pressure units of measure as well as up to five user defined units. See
Table 35, Section 9.2.1, for a listing of the available units of measure and the conversion
factors used by PPC4.
User defined unit definitions specify the number of user units per Pascal (Pa). 1 kiloPascal (kPa),for example, is specified by 0.001 units/Pa.

Note•

The pressure measurement unit selected is range specific. When in agiven range, all functions and settings are represented in the current
measurement unit for that range. However, certain internal and/or
metrological functions (e.g., Q-RPT calibration coefficients) are always
represented in Pa regardless of the active range unit of measure.

•

When the active unit is an altitude unit, the range and upper limit
indications are in kPa if the unit is meters (m) and psi if the unit is feet
(ft).

•

If the pressure unit selected is a water column (inches, millimeters,
meters) the reference temperature for water density must be specified.
In the Advanced User Interface, the temperature is included as part of
the unit name, such as mmH20@4C. In the Basic Interface, thetemperature is specified in a secondary screen. For remote selections
in both Basic and Advanced Interfaces the temperature is assumed to
be 20 ºC unless specified in the Unit remote command (see Section
6.5.4).

•In the Basic Interface, the default pressure units of measure available
under the <Unit> function depend on whether the PPC4 has been set
up as an SI or US version (indicated by SI or US at bottom right ofintroduction screen). The choice of six units available under the<Unit> function can be customized from a wider selection by the user
(see Section 4.5.6). The units available can be reset to default by reset(see Section 3.2.25.2).

 OPERATIONFor Basic Interface see Sections 4.5.13.and 4.5.6.
For Advanced Interface see Section 5.7.6.1.

3.2.11

Measurement Mode

 PURPOSE
To set the measurement mode (absolute, gauge or negative gauge) for the active range.
 PRINCIPLE
PPC4 supports simple, one-step switching between up to three different measurement modes:
Absolute

Measures pressure relative to vacuum (zero is hard vacuum). Range isfrom zero absolute to full scale.

Page 28

3. OPERATING PRINCIPLES

Gauge

Measures pressure relative to atmosphere (zero is ambient pressure).
Range is from zero gauge to full scale, full scale must be greater than zero.

Negative gauge

Measures pressure relative to atmosphere (zero is ambient pressure).
Values are positive and negative, with ranges from negative one
atmosphere to positive full scale. With a BGxxx Q-RPT, negative full scaleis the negative equivalent of positive full scale.

Which measurement modes are available depends on the type(s) of Q-RPT available. There arethree Q-RPT types:
Axxx

Q-RPTs with designators starting with “A” measure pressure relative to a sealed
vacuum reference and are intrinsically absolute. Axxx Q-RPTs support
measurement in absolute, gauge and negative gauge modes. Gauge and negative
gauge modes are accomplished by PPC4’s automated offsetting of atmosphericpressure and dynamic compensation for atmospheric pressure changes between
offsets using an on-board barometer (see Section 3.2.4). Access to absolute andnegative gauge operation can be turned OFF if these modes are not used (seeSection 7.2.5).

Gxxx

Q-RPTs with designators starting with “G” measure positive pressure relative to the
TEST(-) port that is connected to atmosphere.
Gxxx Q-RPTs support
measurement in gauge mode only.

BGxxx

Q-RPTs with designators starting with “BG” measure positive and negative
pressure relative to the TEST(-) port that is connected to atmosphere. BGxxx
Q-RPTs support measurement in gauge and negative gauge modes.

When changing measurement modes for a range, if the full scale of the range is 700 kPa(100 psi) or greater, the full scale is the same in both absolute and gauge modes. If the fullscale is less than 700 kPa (100 psi), the gauge mode full scale is 100 kPa (14.5 psi) lower
than the absolute mode full scale. Gauge and negative gauge mode, when available, have thesame full scale.

Note•

Certain PPC4 settings, including AutoZ ON/OFF (see Section 3.2.22)
are range AND measurement mode specific. See Table 4 for a listingof settings and what they are specific to.

•

Absolute and negative gauge modes on an Axxx Q-RPT can be turned
OFF in the calibration function (see Section 7.2.5). When absolute andnegative gauge mode are turned OFF for an Axxx Q-RPT, only gauge
mode can be activated.

 OPERATIONFor Basic Interface see Section 4.5.15.
For Advanced Interface see Section 5.7.6.2.

3.2.12Set Pressure Automatically PURPOSE
To use the automated pressure control functions of PPC4 to set and maintain target pressure
values.  opens the target screen to initiate the sequence.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Note•

A target pressure entry that exceeds the current upper limit (seeSection 3.2.21) or that is out of range will not be accepted as the target
value.

•

If PPC4 is unable to control pressure or appears to control pressure
poorly, see Section 8 to troubleshoot.

•For PPC4 to set pressures under atmosphere and/or to reliably setpressures under 20 kPa (3 psi) gauge other than zero gauge, avacuum pump must be connected to the EXHAUST port (see Section
2.3.5) and PPC4 must be set up for control using a vacuum reference(see Section 3.2.27.1). Setting zero gauge pressure does not require a
vacuum.

•The  and  direct pressure control keys can be used while
controlling to jog the pressure control target value up or down by thejog step value (see Section 3.2.20). These keys also jog the target
value when in the ENTER target value screen.

•

Due to the manner in which PPC4 handles an automated pressurecommand for zero in absolute pressure measurement mode, a Readycondition can occur at a pressure well outside of the hold limit. Whensetting zero in absolute measurement mode, the Ready condition should
NOT be interpreted as meaning that the pressure is zero within the holdlimit. Ready is an indication that the rate of change of pressure inside
PPC4 has reached the current stability limit. The current pressure
measured by PPC4, not zero, should be used as the value of pressure
applied to the device or system under test.

•

When PPC4 is given a command to set zero in absolute measurementmode, the rate of change of pressure will decrease as the pressure
decreases and the rate will eventually be near zero when the vacuum
pump has pulled down the pressure in the PPC4 and the test volume
as far as possible. To make best use of the Ready/Not Ready
indication when setting zero in absolute measurement mode, set thestability limit (see Section 3.2.3) to a value that represents the rate ofchange of pressure expected when the vacuum pump connected to
the EXHAUST port has reduced pressure as far as possible.

 OPERATIONFor Basic Interface, see Section 4.2.1.
For Advanced Interface, see Section 5.5.1.

3.2.13Control PURPOSE
To set the automated pressure control mode for the active range, customize control
parameters, activate default control parameters.
 PRINCIPLEThe Control function allows the active control mode for the current range to be set to either
dynamic or static. The control mode set is specific to the active range and is saved with that
range when ranges are changed. For a complete description of the operation and purpose ofstatic and dynamic control modes see Section 3.2.2.
When a control mode is selected using the Control function, Control parameters areautomatically set to default values for the active range (see Table 6 for definition of PPC4
default control parameters). The default control parameters have been determined to be
Page 30

3. OPERATING PRINCIPLES

most suitable for the typical user to operate within PPC4 pressure control and measurement
specifications. Each PPC4 default range has default control parameters and AutoRange
automatically sets control parameters appropriate for the AutoRange range.
Control mode parameters can be viewed and customized in the Control function(see Section 5.7.8 in the Advanced Interface and Section 4.4.5 in the Basic Interface).
Customizing the hold and/or stability control parameters changes the conditions required fora Ready condition to occur (see Section 3.2.3). This can be used to increase control speed(reduce time to Ready), usually by decreasing control precision, or to increase precision whichusually decreases control speed. For example, changing the dynamic pressure control hold limit
from its default value of ± 50 ppm of the active range to ± 100 ppm of the active range will
decrease the time required to set a pressure since the limit within which the pressure must be
set has increased. However, it will also increase the maximum possible control error when
Ready is indicated.
Table 6. Default Pressure Control Parameters
STATIC MODE
HOLD
LIMIT
STABILITY
LIMIT

DYNAMIC MODE

± 1 % of range span

± 50 ppm of range span, 5 ppm of
Q-RPT span or 0.4 ppm of controller
span, whichever is greater

50 ppm of range span or 2 ppm of
Q-RPT span, per second, whicheveris greater

50 ppm of range span or 2 ppm of Q-RPT
span, per second, whichever is greater

 OPERATIONFor Basic Interface, see Section 4.4.5.
For Advanced Interface, see Section 5.7.8.

3.2.14Vent

 PURPOSE
The  control key activates a sequence to bring the test pressure to atmosphere.
 PRINCIPLE
The Vent sequence controls the pressure to near atmospheric pressure then opens thesystem vent valve (see Figure 32). In addition to bringing the PPC4 test pressure toatmospheric pressure, the Vent sequence also opens the Q-RPT bypass valve for Gxxx and
BGxxx Q-RPTs and, after a delay, closes the control bypass valve to minimize consumptionof supply gas through the control circuit (See. Figure 31) During the Vent sequence the RED
Vent LED is blinking. Once the RED Vent LED is lighted and steady and the Ready/Not
Ready indicator becomes GREEN then the system is fully vented.
 OPERATIONFor Basic Interface, see Section 4.2.2.
For Advanced Interface, see Section 5.5.3.

3.2.15

AutoTest PURPOSE
To execute a programmed sequence of automated pressure control target values.

Note
AutoTest is available with the Advanced User Interface only.

Page 31PPC4™ OPERATION AND MAINTENANCE MANUAL PRINCIPLE
The AutoTest function is intended to facilitate the execution of a series of pressure control
target values such as when PPC4 is used to run a calibration sequence on a device orsystem being tested.
There are three sequence choices for AutoTest:
Exercise

Cycle the Test Pressure between atmosphere or vacuum and amaximum target pressure such as when exercising a UUT prior tocalibration.
The information to the right of Exercise: in the AutoTest menu is the last
executed exercise sequence, pressure range and number of cycles.

Quick Test

Allows quick definition and execution of a sequence in the current range
and using all of the current settings (pressure unit of measure,measurement mode, control mode, control settings, display resolution).
The information to the right of Quick Test: in the AutoTest menu is thestep size and direction for the last executed Quick Test.

Advanced Test

AutoRanges PPC4 based on the full scale and tolerance of a device
under test, prompts the user through the increments of a calibration
sequence and logs calibration data. The Advanced Test function allows forthe pressure at each target point to be adjusted so that the device under
test reads a cardinal target pressure point. This is particularly useful whencalibrating analog gauges.
The information to the right of Advanced Test: in the AutoTest menu is
the number of saved tests available for selection.

In both the Quick Test and the Advanced Test, the PPC4 records the value of the PPC4
pressure at the time  is used to advance to the next test point. Following the completionof the test the PPC4 values for all of the test points are displayed in a list. If the user iscalibrating an analogue device, such as a gauge, the user can adjust the PPC4 pressure toset cardinal points on the analogue device before advancing to the next pressure. If this isdone, the list of pressures at the conclusion of the test is the list of PPC4 pressurescorresponding to the analogue cardinal points.
 OPERATION
AutoTest is not available with the Basic Interface.
For Advanced Interface see Section 5.7.2.

3.2.16Head PURPOSE
To cause a pressure fluid head correction to be added or subtracted to the pressure
measured by the PPC4 reference pressure transducer in order to predict the pressure at aheight other than the PPC4’s reference level.

Page 32

3. OPERATING PRINCIPLES PRINCIPLE
PPC4 measures gauge or absolute pressure at the height of the rear panel TEST(+) port.
Frequently, when performing a calibration or test, the device or system under test is at adifferent height than the PPC4’s TEST(+) port. This difference in height, frequently called
head, can cause a significant difference between the pressure measured by the PPC4 at its
TEST port height and the pressure actually applied to the device under test which is at adifferent height. In this case, it is useful to make a head correction to the pressure measured
by the PPC4 in order to predict the pressure actually applied at a different height.
PPC4 can calculate head pressures for nitrogen, helium and air as the test gas over its working
pressure range. The HEAD function allows the height difference to be specified and causes
the resulting head pressure to be added to the pressure measured at the TEST port.
The reference height of the PPC4 pressure
measurement is the middle of the PPC4TEST port. The head height should beentered as a positive value if the device orsystem under test is higher than the PPC4and negative if it is lower.

PPC4 PRESSURE CONTROLLER/CALIBRATOR

Note•

Use of the Head function to ensure in tolerance measurements is mostimportant in low absolute pressure ranges. Specifying the headheight within ± 3 in. (7.5 cm) is adequate to ensure that, even in theworst case, the uncertainty on the head correction will be insignificant
relative to the tolerance on the measurement.

•

The Head function is NOT range specific. The Head On or Off status
remains the same as ranges are changed. Edits made to the headsettings are independent of active range or Q-RPT.

•In the PPC4 Basic Interface, when a head correction is being applied,
it is indicated by <h> in the top line of the Main Run Screen (seeSection 4.1). The <h> is not shown when the head correction is zero.

•In the PPC4 Advanced User Interface, the head height and fluid areshown beside Head: on the Main Run Screen (see Section 5.1).

•

When using external Q-RPTs in RPM4, it is recommended that the
RPM4 head height be adjusted to the reference level of the PPC4
before connecting the RPM4. Then, the normal PPC4 reference level
to UUT head corrections can be made for all the Q-RPTs, whether
internal or external to PPC4.

 OPERATIONFor Basic Interface see Section 4.5.16.
For Advanced Interface see Section 5.7.6.3.

3.2.17Purge

 PURPOSE
To execute the PPC4 test system Purge function using the optional Self Purging Liquid Trap
(SPLT). Purge is used to collect and exhaust liquid contaminants from the device or system
under test before they reach the PPC4.

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PPC4™ OPERATION AND MAINTENANCE MANUAL PRINCIPLE
PPC4 is designed to precisely set, control and measure gas pressure. Liquid contaminationof the PPC4 internal pressure control module and/or the Q-RPT module can cause poorpressure control and interfere with pressure measurement. Liquid contaminants that may bepresent in test devices or systems that are connected to the PPC4 TEST(+) port are likely tomake their way back to PPC4’s internal pneumatic system as the test device or system ispressurized and depressurized by PPC4. To every extent possible, only clean hoses andtubing should be used to connect PPC4 to test devices or systems and those devices andsystems should be free of liquid contaminants. However, in the event that PPC4 must used
to test devices or systems that may contain small amounts of liquid contaminants, a Self
Purging Liquid Trap (SPLT) accessory supported by the Purge function is available.
Execution of the PURGE function is automated and proceeds as follows:
If current pressure is greater than 700 kPa (100 psi) gauge, pressure is controlled down
to less than 700 kPa (100 psi) gauge.
Pressure control stops and a 5 second wait occurs.
SPLT exhaust valve is opened.
PPC4 waits until pressure is less than 20 kPa (3 psi) gauge or 110 kPa (16 psi) absolute.
PPC4 internal vent valve is opened with the SPLT exhaust valve left open.

Note•

The Purge function makes use of the PPC4 valve driver option. Valve
driver number 8 is used to actuate the SPLT exhaust valve. Whenmaking use of valve drivers, note that if the Purge function is enabled,
valve driver number 8 will be actuated independently of valve drivercommands. See Section 3.2.23.

•

For the Purge function to execute an optional Self Purging Liquid Trap
(SPLT) must be installed in the test line (see Section 2.3.7.1) and thefunction must have been enabled. To enable with the Basic Interface:<Spec>, <Internal>, <Purge> from the Main Menu (see Section 4.5.7.4).
To enable with the Advanced Interface: [Settings], <Internal>, Purge(see Section 5.7.12.3).

•

 at any time during execution of the purge routine causes the purge
function to abort and returns to the Main Run Screen.

•

The internal volume of the SPLT is about 20 cc. The SPLT will not
operate effectively if the volume of liquid contaminants collected isgreater than about 10 cc. The SPLT is designed to protect the PPC4
only against residual liquid contamination. Even if an SPLT is being
used, precautions should be taken to reduce potential liquidcontamination from the device or system under test as much as
possible before making the connection to the PPC4 TEST(+) port.

•

Do not plug the SPLT exhaust valve. The purge routine can not becompleted with the SPLT exhaust valve plugged and the SPLT’s
protective function will not be effective.

•

If the SPLT is electrically connected to the PPC4, its exhaust valve will
always be open when the PPC4 vent valve is open. If desired, it may
be closed manually using the Driver function (see Section 5.7.4 in the
Advanced Interface or Section 4.4.6 in the Basic Interface).

 OPERATIONFor Basic Interface operation, see Section 4.5.17.
For Advanced Interface operation, see Section 5.7.3.1.

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3. OPERATING PRINCIPLES

3.2.18

Leak Test

 PURPOSE
To run an automated leak check routine that determines the leak rate of the system
connected to the PPC4 TEST(+) port.
 PRINCIPLE
Leaks in the system connected to PPC4’s TEST(+) port can cause differences between thepressure measured by the PPC4 Q-RPTs and pressure in other parts of the test system.
A large leak can cause the PPC4 to be unable to set and control pressures reliably.
The LEAK CHECK function is provided as a means of checking and quantifying the leaks that
may be present in the system.
The principle of the LEAK CHECK function is the measurement of the natural decrease or
increase of pressure in a fixed volume over time. The LEAK CHECK function allows a leakcheck time to be set. The total pressure change and the average rate of change over theleak check time are calculated and displayed.

Note•

Changing the pressure in a test system causes adiabatic temperaturechanges in the gas that need to disipate before a valid leakmeasurement can be made. In general, a 30 second to 1 minute wait
before running a leak check is adequate to allow the adiabatic
temperature change to dissipate and valid leak measurements to be
made. However, stabilization time may be much longer with larger
volumes, higher pressures or with liquid test media.

•

As a general rule, the maximum acceptable leak rate for optimal PPC4
automated pressure control operation and to ensure in tolerance
measurements with default pressure control parameters is 0.5 % of
current range span/minute.

•Leak check is range specific in the sense that leak check is run using
the active range. However, only one set of leak check results ismaintained in memory and each leak test completed overwrites thememory. View leak check always shows the results of the last leakcheck run regardless of the range that is now active. The results
screen includes the range indicator to indicate the range in which theleak check was run.

 OPERATIONFor Basic Interface see Section 4.5.11.
For Advanced Interface see Section 5.7.3.2.

3.2.19Resolution

 PURPOSE
To set the resolution with which measured pressures and other pressure indications andsettings are displayed.
 PRINCIPLE
The resolution with which PPC4 displays pressure values can be adjusted. This feature canbe used to reduce the resolution when lower precision measurements are being made andexcess resolution might confuse or distract the operator.
The resolution setting determines the number of digits with which pressure is displayed.
The resolution is calculated based on the full scale of the range and then rounded to the
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PPC4™ OPERATION AND MAINTENANCE MANUAL

furthest digit to the right. For example, resolution of 0.001 % on a range of 150 kPa is
150 X 0.001 % = 0.0015 which is rounded down to 0.001 kPa.

Note•

Default resolution is 10 ppm of active range span. Resolution is set
automatically by AutoRange (see Section 3.2.8).

•

The resolution setting is range specific. A resolution setting made in
one range does NOT affect other ranges.

•

The measured pressure resolution is fixed for altitude units at 1 m inmeters and 1 ft in feet.

•

The maximum resolution setting is limited in AutoRange ranges thatare less than 10% of the Q-RPT default full scale.

•

The maximum resolution setting when using a utility sensor is 0.001%
of utility sensor span.

 OPERATIONFor Basic Interface, see Section 4.4.2.
For Advanced Interface, see Section 5.7.6.4.

3.2.20Jog

 PURPOSE
Adjust the nominal change in pressure caused by using the jog direct pressure control keys
( and  for Advanced Interface,  and  for Basic Interface).
 PRINCIPLE
The jog direct pressure control keys,  and , increase or decrease pressure by anominal amount each time they are pressed. If pressure control is NOT active, pressing thejog key causes an up or down slow pressure ramp. If pressure control is active, the jog key
causes the pressure control target value to be changed by the amount of the jog step.

Note•

The default jog step is 100 ppm of active range span. The maximum
jog step is 5 % of active range span. Jog step value is set
automatically by AutoRange (See Section 3.2.8).

•

The jog step setting is range specific. A jog step setting made in one
range does NOT affect other ranges.

 OPERATIONFor Basic Interface, see Section 4.4.3.
For Advanced Interface, see Section 5.7.8.2.1.

3.2.21Pressure Limits PURPOSE
To set the upper and lower limit pressure value for a pressure range and measurement mode.
 PRINCIPLEThe Upper Limit function allows the setting of a maximum pressure not to be exceeded whenusing a specific range and measurement mode. Absolute and gauge measurement modes

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3. OPERATING PRINCIPLES(see Section 3.2.11) have their own, specific limits. Negative gauge mode and the BA100K
Q-RPT also have a lower limit.
Automated pressure control targets greater than the upper limit or lower than the lower limit
are not accepted. When the pressure measured by PPC4 exceeds the upper limit or lower limit,
automated or direct manual pressure control is aborted and an intermittent warning beep sounds.
The Upper Limit most often protects the device or system connected to the PPC4 TEST(+)
port from accidental overpressure.

Note
The default upper limit is 105 % of AutoRanged span or 102 % of Q-RPT
default (maximum) range, whichever is lower. The default lower limit is- ATM, except with a BGxxx Q-RPT in which the default lower limit is thenegative equivalent of the upper limit. The default lower limit of a BA100K
is 66 kPa (9.6 psi).

 Caution
Upper limit values are specific to each range and measurement mode. Be
careful not to assume that the upper limit set in one measurement mode
will apply to the other.
For example, if 150 kPa is selected as the upper limit in gauge mode, theupper limit will not be 150 kPa in negative gauge mode of the same range.
 OPERATIONFor Basic Interface, see Section 4.4.4.
For Advanced Interface, see Section 5.7.8.1.

3.2.21.1 Over Pressure Function
In addition to the UL function, PPC4 has an over pressure function.
The over pressure function executes when a Q-RPT measures a pressure that is
104 % of its default span or a utility sensor measures a pressure that is 110 % of
its default span. BG15K Q-RPTs also have a negative over pressure limit.
The BG15K Q-RPT negative over pressure limit is - 17.5 kPa (- 2.3 psi).
When PPC4 is using an external Q-RPT in an RPM4, the PPC4 utility sensor or
Hi Q-RPT acts as a watchdog. If the watchdog measures a pressure greaterthan the maximum pressure of the active external Q-RPT, PPC4 executes theoverpressure function.
The over pressure function causes all pressure control to be interrupted anddisabled, changes the active range to the default range of the Internal, Hi (IH) QRPT or utility sensor and causes the measured pressure display to flash. If the
Q-RPT is a Gxxx or BGxxx, the TEST(+)/TEST(-) bypass valve is opened. The
overpressure function also logs the time and date of the overpressure condition inboth user and factory logs to assist in incident diagnosis (see Section 3.2.27.5).
To recover from an overpressure condition, correct the overpressure conditionand cycle PPC4 power. Be sure to correct the condition that caused theoverpressure before cycling power.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Note
RPM4 has its own, independent overpressure function. Whena Q-RPT on an RPM4 is active, both the PPC4 and the RPM4
may execute overpressure routines in response to an
overpressure condition of the RPM4. See the RPM4 Operationand Maintenance Manual for information on the RPM4
overpressure function.

3.2.22

AutoZero (AutoZ)

 PURPOSE
To offset the PPC4 system Q-RPTs relative to a reference value in order to compensate forpossible changes in Q-RPT zero between full recalibrations.
 PRINCIPLE
AutoZero Purpose and Principle
The main component of the change over time of PPC4 Q-RPTs is change in zero or offset,
independent of span. Offsetting or “rezeroing” PPC4 Q-RPTs relative to a reference between
recalibrations allows measurement uncertainty specifications to be maintained with lessfrequent full calibrations. The PPC4 AutoZero function (AutoZ) provides full on-board support
for the rezeroing process to simplify its application by the user.
The AutoZero function uses three values:
1. Pstd,0: The pressure value indicated by the AutoZ reference, the device that is acting as
the reference relative to which to offset the Q-RPT.
For Axxx (absolute) Q-RPTs in absolute measurement mode, the pressure at which
AutoZ is performed is normally atmospheric pressure and Pstd,0 value can be supplied bymanual entry.
For Gxxx and BGxxx (gauge) Q-RPTs or Axxx (absolute) Q-RPTs in gaugemeasurement mode, Pstd,0 is always zero (atmospheric pressure) which is supplied bydefinition when the Q-RPT is vented to atmosphere.
2. Pu,0: The pressure reading of the Q-RPT, with no AutoZ offset, at the time AutoZ is
performed.
3. Poffset,G and Poffset,A: The difference between the reading of the Q-RPT with no AutoZ
offset (Pu,0) and the indication of the AutoZ reference (Pstd,0) for gauge (G) or absolutemeasurement mode (A):
Poffset = Pu,0 - Pstd,0Poffset represents the change in zero of the Q-RPT relative to the AutoZ standard (Pstd,0).
The AutoZ function manages the determination, storage and application of Poffset for PPC4
system Q-RPTs in absolute and gauge measurement modes.
When the Q-RPT is calibrated, Poffset is set to zero. Poffset is then redetermined at regularintervals using the AutoZ function. The most recent value of Poffset is applied to the Q-RPT
reading to correct for change in zero over time.
The AutoZ function can be turned ON and OFF. Table 8 summarizes the effect of AutoZ ON
and OFF for the three Q-RPT types in different measurement modes.
AutoZ in absolute measurement mode with an Axxx Q-RPT
Q-RPTs with the designation Axxx are intrinsically absolute. They have an evacuated andsealed reference. Axxx Q-RPTs can measure absolute pressure (difference from vacuum).
In absolute measurement mode, the source of Pstd,0 must be an absolute pressure, nominally
atmospheric pressure, with uncertainty significantly better than that of the Q-RPT that isPage 38

3. OPERATING PRINCIPLES

being AutoZeroed. For higher range Q-RPTs, this is easily accomplished with a variety ofdigital barometers or with a lower range Q-RPT in the PPC4 system. For lower range Q-RPTs, apiston gauge or other standard may be required to provide Pstd,0 with low enough uncertainty.
When using an Axxx (absolute) Q-RPT in absolute measurement mode, with AutoZ ON,
absolute pressure is calculated as:
Pabs = Pu - Poffset,A
In absolute measurement mode, execution of the AutoZ function to update the AutoZ value(Poffset,A), is initiated by the operator.
AutoZ in gauge and negative gauge measurement modes with an Axxx Q-RPT,
dynamic compensation for atmospheric pressure
Q-RPTs with the designation Axxx are intrinsically absolute but they can also be used in gauge
and negative gauge measurement modes (difference from atmosphere) (see Section 3.2.11).
Gauge measurement mode is achieved by subtracting the value of atmospheric pressure fromthe Q-RPT’s absolute reading using AutoZ and by dynamically compensating for changes inatmospheric pressure between opportunities for AutoZ to execute (see Section 3.2.4).
In gauge measurement modes on an Axxx Q-RPT, the value of Pstd,0 is always zero gaugepressure. Zero gauge pressure, by definition, is applied to the Q-RPT when it is vented toatmosphere. In gauge measurement modes, the AutoZ routine is run automaticallywhenever the PPC4 is in the vented condition. This ensures regular automated updating of
the Poffset,G value corresponding to atmospheric pressure. Gauge pressure is the measured
absolute pressure, Pu, minus Poffset,G.
Pgauge = Pu - Poffset,GWhen AutoZ is ON, dynamic compensation for atmospheric pressure is also applied tocompensate for changes in atmospheric pressure between AutoZ updates (see Section 3.2.3).
The measured gauge pressure is calculated using ∆Patm to correct the value of Poffset.G.
Pgauge = Pu - Poffset.G - ∆Patm
In gauge measurement mode with an Axxx RPT, execution of the AutoZ function to update
the value of Patm,0, occurs automatically whenever PPC4 is vented. Updating ∆Patm occurs
automatically continuously during unvented operation.
AutoZ in gauge measurement mode with a Gxxx or BGxxx Q-RPT
Q-RPTs with the designation Gxxx or BGxxx are intrinsically gauge. They have an
atmospheric reference port and measure gauge pressure (difference from atmosphere).
In gauge measurement mode the value of Pstd,0 is always zero gauge pressure. Zero gaugepressure, by definition, is applied to the Q-RPT when it is vented to atmosphere. In gaugemeasurement mode, the AutoZ routine is run automatically whenever the PPC4 is in thevented condition. This ensures the regular automated updating of the Poffset,G value.
When using a Gxxx Q-RPT in gauge measurement mode, with AutoZ ON, gauge pressure is
calculated as:
Pgauge = Pu - Poffset,G
AutoZ ON/OFF
The AutoZ function can be turned ON and OFF, separately for gauge and absolutemeasurement modes, see Table 7. AutoZ ON and OFF summarizes the effect of AutoZ ON
and OFF for different Q-RPT types in absolute and gauge measurement modes.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Table 7. AutoZ ON and OFF
Q-RPT
TYPE

Axxx
(or utility
sensor)

Gxxx
or
BGxxx

MEASUREMENT
MODE

Absolute

Gauge ornegative gauge

Gauge ornegative gauge

AutoZ
STATUS

PoffsetAPPLIED

ON

YES

OFF

NO

ON

∆Patm
APPLIED

Not Applicable

OFF
ON

YES

OFF

NO

When initiatedby operator
Not available

NO

Automaticallywhen PPC4 in
VENT condition

Not Applicable

Automaticallywhen PPC4 in
VENT condition

YES
YES

AutoZ
ROUTINE
RUNS

No

Recommendations for the Use of the AutoZ Function
The AutoZ function provides a powerful and easy to use tool for improving the stability overtime of PPC4 internal and external Q-RPTs and maximizing the recalibration interval bycompensating for change in zero between full recalibrations. The following simple
recommendations will help ensure that you use this feature to best advantage.
•

In gauge measurement mode: Always leave AutoZ ON when operating.

•

In absolute measurement mode: Always leave AutoZ ON when operating if the AutoZ
routine has been run regularly using a valid Poffset reference.

•

In absolute measurement mode: Run AutoZ at least every 30 days or when PPC4 has
been exposed to temperature changes exceeding 15 ºC (36 ºF).

•

In absolute measurement mode: Run AutoZ only when a reference whose
measurement uncertainty is known to be significantly better than that of the Q-RPT to be
AutoZeroed is available. Keep range ratios in mind when comparing uncertainty.
A ± 0.01 % FS barometer is roughly 10 times better than an ± 0.01 % 1 MPa (150 psi)
Q-RPT because the Q-RPT/barometer pressure ratio is 10:1. The measurement
uncertainty comparison should be made at 30 % of span for both standard class andpremium class Q-RPTs. Though it may not be practical, the best possible reference withwhich to run AutoZ in absolute measurement mode on Q-RPTs of A350K or lower, is agas operated piston gauge (such as a DHI PG7601) applying a pressure near 100 kPa to
the PPC4 test port. The best day to day reference is a properly calibrated DHI RPM4
with a BA100K or A100K Q-RPT.

•In absolute measurement mode: Allow the PPC4 to stabilize at atmospheric pressure
and ambient temperature for 10 to 15 minutes before running AutoZ.

Note•

The AutoZ function and values are Q-RPT AND measurement mode
(gauge/negative gauge or absolute) specific.

•

When AutoZ is run for an external Q-RPT in an RPM4, the PPC4
causes the RPM4 to run its own AutoZero routine. The RPM4 Q-RPT
is then AutoZeroed as if it had been AutoZeroed independently of the
PPC4.

•

Poffset should be zero for Axxx Q-RPTs when the PPC4 is new or has
just been calibrated. Poffset should be roughly equal to atmosphericpressure for an Axxx (absolute) Q-RPT operating in gauge mode.

•

The value of Poffset is always displayed and entered in Pascal (Pa).
Normally, in day to day operation, the value of Poffset is changed byrunning AutoZ (see Section 5.7.5.1 for Advanced Interface or Section
4.5.1.2 for Basic Interface), not by direct editing.
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3. OPERATING PRINCIPLES

3.2.22.1 Edit AutoZ Caution
The edit AutoZ function should be used with great caution asentering inappropriate values and turning ON AutoZ may resultin out of tolerance measurements. In normal day to day
operation, the value of the AutoZ offset, Poffset, should bechanged using the run AutoZ function (see Section 5.7.5.1 for
Advanced Interface or Section 4.5.1.2 for Basic Interface) inabsolute measurement mode or automatically in gauge modes.
Before editing Poffset, see Section 3.2.22.

Note•

The value of Poffset is always displayed and entered in
Pascal (Pa).

•

Edit and view AutoZ are not available for external Q-RPTs
in gauge mode.

 OPERATIONFor Basic Interface, see Section Section 4.5.1.1.
For Advanced Interface, see Section 7.2.7.2.

3.2.22.2 Run AutoZ
Note•

Run AutoZ applies only to Axxx Q-RPTs in absolutemeasurement mode.
In gauge and negative gaugemeasurement modes, AutoZ is run automaticallywhenever the PPC4 is in the VENT condition.

•

Allow the PPC4 to stabilize at atmospheric pressure andambient temperature for 10 to 15 minutes before running
AutoZ.

•

While the value of Pstd,0 is entered in the current pressure
unit of measure, the value of Poffset is always in Pascal
(Pa).

•

If running AutoZ results in a value of Poffset that is greaterthan ± 0.005 % FS of the span of the Q-RPT that is being
AutoZeroed, the Q-RPT and/or the reference used as thesource of Pstd,0 may be out of tolerance or the AutoZ
process may have been faulty. Before activating a new
Poffset greater than ± 0.005 % FS of the active Q-RPT, checkto be sure that both the Q-RPT and the reference were ingood working order, properly vented to stable
atmospheric pressure, at the same height, and reading inthe same pressure units when AutoZ was run.

•

When running AutoZ, if a HEAD correction is currently
active (see Section 3.2.16), it is momentarily disabled to
avoid “zeroing out” the head value.

 OPERATIONFor Basic Interface, see Section Section 4.5.1.2.
For Advanced Interface, see Section 5.7.5.1.

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3.2.23

Drivers PURPOSE
To control the output signals of PPC4’s 8 channel, 12 V external drivers.
 PRINCIPLE
PPC4 external drivers are available to drive peripheral equipment in a PPC4 system, forexample, solenoid valves or the optional Self Purging Liquid Trap (SPLT). The driverelectrical connections are available from a rear panel connector

 Caution
The PPC4 PURGE function makes use of the valve driver option. Valve
driver number 8 is used to actuate the SPLT exhaust valve. The SPLT
exhaust valve Is actuated when performing the Purge function and in the
background every time the PPC4 VENT function is used. When making useof valve drivers, note that when the Purge function is enabled, valve driver
number 8 will be actuated independently of user initiated valve drivercommands (see Section 3.2.17).
 OPERATIONFor Basic Interface, see Section 4.4.6.
For Advanced Interface, see Section 5.7.4.

3.2.24

Remote PURPOSE
To configure the PPC4 COM1, COM2, IEEE-488 (GPIB), or Ethernet communication ports.
To test COM1 and COM2 communications. To select remote programming communications
format. (COM1 and COM2 ports are standard on all PPC4 controllers. IEEE-488 (GPIB) andLAN ports are installed only if the appropriate communication option is purchased.) PRINCIPLE
The PPC4 has two RS232 communications ports referred to as COM1 and COM2 as well asa front panel USB port. Optionally, the PPC4 may be configured with either an IEEE-488(GPIB) port or Ethernet port. COM1, IEEE-488, and Ethernet are for communicating with ahost computer (see Section 6.2). COM2 is reserved for communicating with an external
device (i.e. RPM4, multimeter, etc.). Port settings can be viewed and changed using front
panel commands. The USB port(s) allow connection with a PC using PPC4 Cockpit software(see Section 6.2).
The PPC4 has 3 different syntax formats available for remote program commands. Classic
format is compatible with previous PPC products and is the default format. Enhanced format
follows the syntax, format, and status reporting features of IEEE Std 488.2. Alternatively, acustom command format defined by the Command Interpreter Editor is selectable. The
details of each are covered in Section 6.4 and the command interpreter documentation,
included with the PPC4 API documentation when PPC4 Cockpit is installed (see Section
6.2.2). Select and view the active command format.
 OPERATIONFor Basic Interface see Section 4.5.2.
For Advanced Interface see Section 5.7.9.

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3. OPERATING PRINCIPLES

3.2.25Reset PURPOSE
To reset various PPC4 settings to default or factory values.
 PRINCIPLE
PPC4 stores its user definable settings in non-volatile memory. The reset menu allows theuser to selectively or completely reset these settings to factory defaults. This clears out any
settings that the user has made, and should be used only to restore the PPC4 to a known
state. PPC4 goes through its power up sequence after any type of reset is executed.

 Caution
PPC4 reset functions will change current settings to factory defaults.
These may include settings vital to PPC4 operation and affecting thecalibration of the quartz reference pressure transducers (Q-RPTs). Resetfunctions should only be used by qualified personnel with knowledge ofreset consequences. Reset functions should not be used experimentally.
Reset menu choices include:
Settings

to reset general system operating parameters (see Section 3.2.25.1).

Units

to reset unit of measure functions (see Section 3.2.25.2).

AutoTest

to reset AutoTest parameters and clear the AutoTest data log (see Section
3.2.25.3).

Calibration

to reset internal calibration coefficients and modes (see Section 3.2.25.4).

All

to reset all settings except ID and security password to factory default values(see Section 3.2.25.5).

3.2.25.1 Settings
 PURPOSE
Sets most general operating parameters back to default values. Does not affectcalibration coefficients, remote interfaces or AutoRange ranges. Reset Settings
resets are itemized in Table 8.
Table 8. Reset Settings
RESULTSEE
SECTION

Unit

Returns pressure unit of measure to first of six available.

3.2.10Mode

Returns measurement mode to the natural Q-RPT mode.

3.2.11

AutoRange

Hi Q-RPT or utility sensor default range.

3.2.8

Head

0 cm height and Nitrogen medium.

3.2.16RESET

Control Mode

Dynamic

3.2.2

Control Limits

Default values of Hi RPT default range.

3.2.13Upper Limit

Value of Hi RPT default range.

3.2.21

Note: May be limited based on external Q-RPT SDS
pressure rating (see Section 3.2.5).
Resolution

0.001% FS of Hi RPT default range.

3.2.19Purge

Disable purge function.

3.2.17

AutoZ

AutoZ On. Poffset value not affected.

3.2.22

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Control ReferenceAuto.

3.2.27.1

Leak Check

15 second run time

3.2.18Screen Saver

10 minutes to activation (Basic Interface)

3.2.26.1

1 hour to activation (Advanced Interface)
Key Sounds

Medium

3.2.26.2

TEST (-) Vent

Automatic.

3.2.27.5

Control Configuration

Return to default control coefficients.

7.5

 OPERATIONFor Basic Interface see Section 4.5.4.1.
For Advanced Interface see Section 5.7.5.3.1.

3.2.25.2 Units PURPOSE
Resets Unit selections to factory defaults. For the Basic Interface, resets to the
SI or US default selections depending on whether the PPC4 has been factory set for
SI or US (see Section 3.2.10). For the Advanced Interface, clears the Favorites list.
Sets the user defined unit(s) to default names and 1.000/Pa (see Section
5.7.6.1.3 for the Advanced Interface or Section 4.5.6 for the Basic Interface).
 OPERATIONFor Basic Interface see Section 3.2.25.2
For Advanced Interface see Section 5.7.5.3.2.

3.2.25.3 AutoTest PURPOSE
Resets Exercise, Quick Test and Advanced Test to default characteristics (seeSection 3.2.15).
 OPERATION
Reset AutoTest not available in Basic Interface.
For Advanced Interface see Section 5.7.5.3.3.

3.2.25.4 Calibration
 PURPOSE Caution
The Reset Calibration function will reset Q-RPT, utility sensor
and barometer calibration coefficients and settings and reset
AutoZ values to zero.
This will change the PPC4 calibrationand could cause it to make out of tolerance measurements.
Clears all user values affecting the calibration of Q-RPTs, utility sensor and theon-board barometer. Does not clear factory coefficients. Reset Calibration
resets are itemized in Table 9.

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3. OPERATING PRINCIPLESTable 9. Reset CalibrationRESET

RESULT

SEE SECTION

All Q-RPT user calibration
coefficients

PA to zero, PM to 1.

7.2.1.1, 7.2.7

Axxx Q-RPT absolute andnegative gauge mode

ON.

7.2.5

Utility Sensor calibration
coefficients

PA to zero, PM to 1.

7.4

On-board barometer
calibration coefficients

PA to zero, PM to 1.

7.3

Calibration date

Set all dates to 19800101.

AutoZ values

All Poffset values to zero for absolute mode and101325 Pa for gauge and negative gauge modes.

3.2.22

AutoZ function

ON, all Q-RPTs, all measurement modes.

3.2.227.2.7, 7.4, 7.3

 OPERATIONFor Basic Interface see Section 4.5.4.3.
For Advanced Interface see Section 5.7.5.3.4.

3.2.25.5 All
 PURPOSE Caution
The Reset - All function clears and deletes large amounts ofuser defined information including critical calibration data.
Combines all resets in one global reset command that clears the entire user
section of non-volatile memory returning PPC4 to the “as delivered” condition
except the ID function (see Section 3.2.27.1) and the security level password(see Section 3.2.26.4). Reset All resets are itemized in Table 10.
Table 10. Reset AllRESETRESULT

SEE SECTION

Reset – Sets

All the resets of Reset – Sets

3.2.25.1

Reset – Units

All the resets of Reset - Units

3.2.25.2

Reset – AutoTest

All the resets of Reset - AutoTest

3.2.25.3

Reset – Calibration

All the resets of Reset - Calibration

3.2.25.4

Remote Interfaces

COM1, COM2, Ethernet andinterfaces to default settings.

Remote Communications

Remote command format to Classic.

3.2.24

Security (Level)Low

3.2.26.4

 OPERATIONFor Basic Interface see 4.5.4.4
For Advanced Interface see Section 5.7.5.3.5.

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IEEE-488.2

3.2.24

PPC4™ OPERATION AND MAINTENANCE MANUAL

3.2.26Preferences PURPOSE
To access a menu of PPC4 operational preferences and functions.

3.2.26.1 Screen Saver
 PURPOSE
To adjust the PPC4’s Screen Saver settings.
 PRINCIPLE
PPC4 has a Screen Saver function which causes the display to go into a screen
saving mode after receiving no front panel input for a certain amount of time. The
screen saving mode and default time depends on the PPC4 local interface
configuration: Basic or Advanced. The default screen saver time activates thescreen saver after 10 minutes for Basic Interface and 1 hour for Advanced
Interface. The screen saver activation time can be adjusted by the user orscreen saving can be completely eliminated.

Note
Setting screen saver time to zero (Basic Interface) or off(Advanced Interface) eliminates the Screen Saver function sothat the display permanently remains on and at full brightness.
 OPERATIONFor Basic Interface see Section 4.5.5.1.
For Advanced Interface see Section 5.7.7.1.

3.2.26.2 Sounds
 PURPOSE
To adjust or suppress the PPC4 key press sounds.
 PRINCIPLE
PPC4 is equipped to provide audible feedback and alarms. The sounds areused for the following indications:
Valid key press

Invalid key press
Leak check completed

Brief beep. Choice between three frequencies or
NO sound is available (see Sections 4.5.5.2,
5.7.7.2).
Descending two tone “blurp”.
Three two second beeps (see Section 3.2.18).

Upper or lower limit exceededIntermittent one second beeps (see Section 3.2.21)

External device not connected

Eight second high frequency beep(see Section 2.3.6)

Pmax! (overpressure limit) exceeded

Eight second high frequency beep(see Section 3.2.21.1).

 OPERATIONFor Basic Interface see Section 4.5.5.2.
For Advanced Interface see Section 5.7.7.2.
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3. OPERATING PRINCIPLES

3.2.26.3 Time PURPOSE
To view and edit the PPC4 internal time and date settings.

Note•

The PPC4 date and time are set to United States MountainStandard Time in the final test and inspection process at
the factory. If desired, use the TIME and DATE functions
to set your local time and date.

•

The PPC4 has an internal real time clock that is used fordate and time stamping calibrations and internal logs.

 OPERATIONFor Basic Interface see Section 4.5.5.3.
For Advanced Interface see Section 5.7.7.3.

3.2.26.4 Language PURPOSE
To specify the language for PPC4 Advanced Interface display, headings, menus
and screens.

Note•

The language selection affects to headings, field names
and on-screen messages. Numeric displays, includingpressure units, buttons and DHI trademarked terms, suchas AutoRange, are always in English.

•

Remote commands and their responses are always in
English, regardless of language setting.

 OPERATION
Languages other than English are not available.

3.2.26.5 Security
 PURPOSE
To set user protection levels to restrict access to certain functions and to edit the
password required for changing user levels.
 PRINCIPLE
PPC4’s front panel user interface provides the means to access all PPC4 user
defined data, settings and functions including calibration data. Inadvertent,
uninformed or unauthorized altering or deleting of data, settings and functions
could require extensive reconfiguration by the user and might cause invalid
readings and behavior. For these reasons, depending upon the application inwhich PPC4 is being used, it may be desirable to restrict access to certain
functions for certain users. The user level function provides a means of restricting
access to certain functions. Four different levels of security are available.
Access to changing security levels can be left open, or be protected by a password.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Security Levels
The security levels are structured to support typical operating environments asfollows:
Off

This level is intended for use only by the system manager and/or
calibration facility. It allows access and editing in all areas including
critical metrological information.

Low

Low security is designed to protect the specific metrologicalinformation and SYSTEM DIAGNOSTIC AND MAINTENANCE
functions of the system against accidental alteration. It is intended foran advanced operator performing many different tasks. Low security
is the default user level setting.

High

High security is designed to protect all operating parameters. It is
intended to minimize operator choices, for example to perform
repeated identical calibrations under consistent conditions.

 Caution
PPC4 is delivered with the security level set at low to avoid
inadvertent altering of critical internal settings but with accessto changing security levels unrestricted. It is recommended
that the low security level be maintained at all times during
normal operation. If there is a risk of unauthorized changing of
the security level, changing authority should be password
protected.
The security levels are structured to support typical levels of operation as shownin Table 11 and Table 12. Security levels prevent execution of the functions
accessed by the key strokes marked by “•” or, in some cases with the Advanced
Interface, prevent changes from being saved – thus allowing viewing of settings
without allowing changes to be made:Page 48

3. OPERATING PRINCIPLESTable 11. Security Levels, Advanced Interface
FUNCTION

LOW[AutoRange], [Delete Range][AutoRange], [Save Range]•[Settings], <Internal>, Event Log, [Clear Log]
[Settings], <Preferences>, Screen Saver[Settings], <Preferences>, Sounds[Settings], <Preferences>, Time
[Settings], <Pressure>, Pressure Unit, [Reset[Settings], <Pressure>, Pressure Unit, <User Units>[Settings], <Remote>•••[Settings], Calibration, [Barometer][Settings], Calibration, [Hi RPT]
[Settings], Calibration, [Lo RPT]
[Tools], <AutotTest>, Advanced Test, [Delete][Tools], <AutotTest>, Advanced Test, [Edit][Tools], <AutotTest>, Advanced Test, [New][Tools], <System>, Control Configuration[Tools], <System>, Resets[Tools], <System>, Run AutoZ

HIGH

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

“•” indicates changes in the function/menu are NOT allowable.

Table 12. Security Levels, Basic Interface
FUNCTION

LOW<Setup>, <Range><Spec>, <Log>, clear log•<Spec>, <Pref>, <ScrSvr><Spec>, <Pref>, <Sound><Spec>, <Pref>, <Time><Spec>, <Punit><Spec>, <Remote>•<Spec>, <Cal><Spec>, <Internal>, <Config><Spec>, <Reset><Spec>, <AutoZ>“•” indicates the function/menu is NOT accessible.

Page 49

HIGH

•
•
•
•
•
•
•
•
•
•
•

PPC4™ OPERATION AND MAINTENANCE MANUAL OPERATIONFor Basic Interface, see Section 4.5.5.5.
For Advanced Interface, see Section 5.7.7.5.

3.2.27

Internal Functions

 PURPOSE
To view, set, adjust, and maintain various aspects of PPC4’s internal operation.

3.2.27.1 Identification
 PURPOSE
To view or edit the PPC4 user ID and to view the PPC4 serial number.

Note
The ID can be set remotely from a computer which is moreconvenient than entering characters from the keyboard (seeSection 6.5.4, ID command). The ID is not cleared or reset by
any RESET function (see Section 3.2.25).
 OPERATIONFor Basic Interface see Section 4.5.5.4.
For Advanced Interface see Section 5.7.12.1.

3.2.27.2 Control Reference PURPOSE
To specify whether PPC4 should automatically determine whether a vacuum
source or atmospheric pressure is connected to its EXHAUST port or to
manually set the EXHAUST port condition.
 PRINCIPLE
The PPC4 exhaust (down) control valves and the output of the exhaust pressure
regulator are connected to the PPC4 EXHAUST port (see Figure 31).
The response of the pressure control module, particularly when controllingpressure near and under atmospheric pressure, changes depending on whether
the EXHAUST port is connected to a vacuum source or left open to atmosphere.
To use the proper pressure control algorithms, PPC4 must know the condition of
the EXHAUST port.
The Control Reference function allows the PPC4 to know whether its EXHAUST
port is at vacuum or atmospheric pressure. An independent exhaust pressure
sensor measures the pressure present at the port. Normally, the exhaust sensor
output is used automatically by PPC4 to determine the EXHAUST port condition.
If desired, this automatic determination can be overridden and the EXHAUST
port condition set manually.
The Control Reference function allows setting of whether the EXHAUST port
condition will be determined automatically using the exhaust sensor or set
manually. It also allows viewing of the current status of the EXHAUST port.

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3. OPERATING PRINCIPLES

Note•

The normal Control Reference setting is Auto. With thissetting, the operator need not be concerned withinforming the PPC4 of EXHAUST port pressure conditions
as PPC4 determines the existing condition automatically.
The other settings are normally used only for special
applications or trouble shooting. Pressure control nearand under atmospheric pressure will not operate properly
if the Control Reference is not set correctly.

•

The Control Reference setting is not range or control
mode specific.

•

The setting made in Control Reference is common across
Q-RPTs and ranges as they are changed.

 Caution
Before connecting a vacuum pump or vacuum source to the
PPC4 EXHAUST port, see Section 2.3.5 for information on
vacuum connection requirements and precautions.
 OPERATIONFor Basic Interface, see Section 4.5.7.2.
For Advanced Interface, see Section 5.7.12.2.

3.2.27.3 Barometer PURPOSE
To view the value of atmospheric pressure as measured by the PPC4 on-board
barometer.

Note
There is no on-board barometer in PPC4’s that have Gxxx
(gauge) internal Q-RPTs only.
 PRINCIPLE
PPC4’s that include an Axxx (absolute) and/or BGxxx (bi-directional gauge)
Q-RPT or a utility sensor (Auxxx) are equipped with a separate, on-board
barometer. The atmospheric pressure measurements made by the on-board
barometer are used for dynamic compensation of atmospheric pressure when
using
an
Axxx
Q-RPT to make gauge pressure measurements (see Section 3.2.4 and 3.2.11) andfor static pressure compensation when using a BGxxx Q-RPT.

Note•

See Figure 31 for schematics showing the position of the
on-board barometer in PPC4’s measurement system.

•

The on-board barometer is a low accuracy sensor used
only for measuring small changes in atmosphericpressureover
shortperiods
oftime(see Section 3.2.4) and for line pressure compensation whenusing a BG15K Q-RPT. PPC4 measurement uncertainty
does not depend on the measurement uncertainty of the
on-board barometer.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

3.2.27.4 Purge
 PURPOSE
To enable and disable the PURGE function which automate use of the optional
Self Purging Liquid Trap (SPLT) (see Section 3.2.17).

 Caution
When the purge function is enabled, PPC4 makes backgrounduse of valve driver channel #8 independently of user actions(see Sections 3.2.17, 3.2.23).

3.2.27.5 Log
 PURPOSE
To view and/or clear the PPC4 event log.
 PRINCIPLE
PPC4 records to a log each time one of the following events occurs:•

Pmax! of an internal PPC4 Q-RPT or utility sensor is exceeded (see Section
3.2.21.1).

•

A memory fault occurs.

NoteOver pressure events on external Q-RPTs are not logged on the
PPC4. They are logged in the RPM4’s log (see the RPM4
Operation and Maintenance Manual).
 OPERATIONFor Basic Interface, see Section 4.5.9.
For Advanced Interface, see Section 5.7.12.4.

3.2.27.6 TEST (-) Vent
 PURPOSE
To cause a PPC4 or external RPM4’s Gxxx or BGxxx Q-RPT TEST (-) vent valve
to stay open or closed rather than open and close automatically.

Note
This feature is active only when the active Q-RPT is a Gxxx
(gauge) or BGxxx (bi-directional gauge) Q-RPT.
 PRINCIPLEA PPC4 or an RPM4 equipped with a Gxxx (gauge) or BGxxx (bi-directional
gauge) Q-RPT has a TEST (-) vent valve in its Q-RPT module (see Figure 13).
The TEST (-) vent valve connects the TEST (-) port to the VENT port which also
connects the Q-RPT and the device or system under test low side toatmosphere.
In normal PPC4 operation, the TEST (-) valve is closed
automatically whenever the PPC4 is performing fine pressure control to isolate
the TEST (-) circuit from fluctuations in ambient pressure. The valve is opened
at all other times. This ensures that the pressure in the TEST (-) circuit does not
move too far away from atmospheric pressure as it might if it were permanently
shut off. In normal RPM4 operation as an external device to a PPC4, the TEST
Page 52

3. OPERATING PRINCIPLES(-) valve is normally closed. It is only opened when PPC4 is controlling withcoarse pressure control.
Allows the TEST (-) vent valve to be set to be permanently open, permanently
closed or to operate in its default automated condition. It also allows the current
status of the valve to be viewed.

Note•

The normal setting for the TEST (-) vent valve is Auto inwhich PPC4 automatically controls the valve based on
current PPC4 operation. Manual settings should only be
selected by advanced users.

•

When the active Q-RPT is an external RPM4 Q-RPT, theTEST (-) Vent operation applies to the RPM4 Q-RPT
module. The TEST (-) Vent settings made from the PPC4,
apply only as long as the RPM4 is a PPC4 external device.
When the RPM4 power is cycled, the RPM4 TEST (-) Vent
will return to its original state.

•

The TEST (-) Vent function setting always applies to theactive Q-RPT module, whether the module is internal to
PPC4 or in an external RPM4 (see the RPM4 Operation and
Maintenance Manual).

 Caution
If the PPC4 detects a condition in which it determines there
could be a risk of overpressure to the RPT by opening the TEST(-) Vent valve when a Manual Open is requested, a message
indicating a DP overpressure risk is displayed. If this message
is displayed, return to normal operation, vent the PPC4 and try
again.
 OPERATIONFor Basic Interface, see Section 4.5.7.5.
For Advanced Interface, see Section 5.7.12.5.

3.2.28Calibration

 PURPOSE
To calibrate the PPC4 utility sensor, Hi and/or Lo Q-RPTs and adjust the on-board
barometer. This function is considered part of PPC4 maintenance and is therefore coveredin the maintenance section of this manual (see Sections 7.2, 7.3 and 7.4).
 OPERATION
See Sections 7.2, 7.3 and 7.4.

3.2.29Measurement Uncertainty

 PURPOSE
PPC4 has the ability to configure, calculate and display the uncertainty in pressure for eachcontrolled pressure target. The uncertainty value is available locally with the Advanced
Interface and is also available remotely in the response to the PRR command for all PPC4models (see Section 6.5.4, PRR Command). Uncertainty can be defined with or without
control components (delivered or measured pressure uncertainty). Uncertainty components
are explained below and default values are given in Table 13.
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PPC4™ OPERATION AND MAINTENANCE MANUAL PRINCIPLE
The following uncertainty components can be configured for pressure uncertainty calculation,
displayed when the PPC4 is Ready.

3.2.29.1 Product Uncertainty
Product uncertainty is a combination of reference, repeatability, linearity,hysteresis and slope stability uncertainties.
There are three quantities thatdefine this component. The relative uncertainty (% of reading), threshold
uncertainty (% of AutoRange span) and the scaling factor for the threshold when
the Q-RPT is AutoRanged. The product uncertainty is the maximum of therelative and threshold uncertainties for a given measured pressure.
Figure 8 shows the relative (% of reading) and threshold (% of span)
uncertainties as well as the resulting product uncertainty for a typical Q-RPT.

Figure 8. Product Uncertainty Illustration

3.2.29.1.1

Relative Uncertainty (% of Reading)

Relative uncertainty is entered as a percent value and is multiplied by the current
pressure when Ready to determine the relative uncertainty.

Note
Premium and standard class Q-RPTs have a % of reading
uncertainty component. For full scale standard (“f” class) QRPTs the % of reading is equal to zero.

3.2.29.1.2

Threshold Uncertainty (% of Span)

Threshold uncertainty is a percent of AutoRanged span. The threshold
uncertainty scales down when the Q-RPT has an AutoRanged Range below the
Q-RPT Default span (see Section 3.2.8).

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3. OPERATING PRINCIPLES

3.2.29.1.3

Scaling Factor (Scale)

Scale specifies the lower limit for scaling for the threshold uncertainty. If a
Q-RPT is AutoRanged below the scaling factor the threshold remains at thevalue determined by the scaling factor (see Table 13).
Example 1 - A premium Q-RPT with default coefficients is AutoRanged to 20% of
the Q-RPT span. The threshold will be at 30% of 0.0024% of the Q-RPT spanrather than 20% of 0.0024% of the Q-RPT span because the default scaling
factor is 30% for a premium Q-RPT.
Example 2 – A standard Q-RPT with default coefficients is AutoRanged to 50%of the Q-RPT span. The threshold will be at 0.003% of the Q-RPT span rather
than 50% of 0.003% of the Q-RPT span because the default scaling factor for astandard Q-RPT is 100%.

3.2.29.2 Head
Head specifies the uncertainty of head height and is specified in the active height
unit (cm or in). The value is converted to pressure uncertainty with standard
gravity and the calculated density of the fluid at measured pressure.

3.2.29.3 Zero Stability
Zero stability is an uncertainty based on the zero stability of the Q-RPT. Twovalues may be specified, one for when AutoZero is ON and one when AutoZero
is OFF (see Section 3.2.22). The values are expressed in percent of Q-RPT
span. Zero stability is inapplicable for Gauge Q-RPTs.

Note
The value for zero stability with AutoZero ON is equal to zero bydefault. If edited by the user, the value should be based on how
often the AutoZero has been performed and the uncertainty of
the AutoZero reference (see Section 3.2.22).

3.2.29.4 Control Uncertainty
When delivered pressure uncertainty is desired an additional uncertainty can be
added to the measured pressure uncertainty.
The control uncertainty
calculations are based on the active control parameters (see Section 3.2.2) so it
is not necessary to enter additional values.

3.2.29.4.1

Dynamic Control

The control uncertainty during dynamic control when the PPC4 is Ready is equal
to the hold limit (see Section 3.2.2). Dynamic control uncertainty assumes thatthe measured pressure is equal to the target pressure with an uncertainty equal
to the control hold limit.

3.2.29.4.2

Static Control

The control uncertainty during static control is defined by the stability setting andthe read rate of the PPC4. Typically, the control uncertainty in static mode isnegligible unless the stability limit is set abnormally high.

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PPC4™ OPERATION AND MAINTENANCE MANUALNote
In dynamic mode, the pressure value returned from the PR andPRR commands (see Section 6.5.4, PR and PR Commands) isthe measured pressure, not the target pressure. The control
uncertainty is based on the target pressure and may beconsidered conservative when applied to the measured
pressure. The value of control uncertainty may be considered
pertinent, however, since the measured pressure can vary
within the hold limit while Ready.
Table 13. Default Values for PPC4 Uncertainty Components
Q-RPT CLASSUNCERTAINTYPRODUCTZERO
STABILTY

FULL SCALE STANDARD

STANDARD

PREMIUM

F CLASSS CLASSP CLASSREADING

0.000%

0.010%

0.008%

SPAN

0.015%

0.003%

0.0024%SCALE30%, 10% for G15K, BG15K

100%

30%

HEAD

0.0 (cm or in)

0.0 (cm or in)

0.0 (cm or in)

AUTOZ ON*

0.000%

0.000%

0.000%

AUTOZ OFF*

0.005%

0.005%

0.005%*Does not apply to gauge type

3.2.29.5 Combining uncertainties
3.2.29.5.1

Measured Pressure Uncertainty

Measured pressure uncertainty is the combination of the product uncertainty andthe uncertainties in pressure head and zero stability.
22

× ρ gas × g std  U AutoZ × S QRPT

U
 U
U meas = 2 ×  prod  +  head
 +

2
2
3

 
 

2

where:
Umeas : Measured pressure uncertainty.
Uprod : Product uncertainty = Max [(Uread x Pcurr), (Uspan x AutoRange Span)] (seeFigure 6).
Pcurr : Current measured pressure.
Uspan : Threshold uncertainty component. Allowable scaling is defined by“Scale” which specifies the extent to which the uncertainty can be
downranged.
Uhead : Uncertainty of head height measurement in cm or inches.

ρgas: Density of the test gas. In gauge mode replaced with (ρgas - ρair), whereρair is standard air density, 1.2 kg/m3.

gstd: Standard gravity 9.80665 m/s2.

UAutoz : Uncertainty associated with zero drift of the Q-RPT, specified with AutoZ
On and separately with AutoZ Off.
SQRPT : Q-RPT span.

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3. OPERATING PRINCIPLES

Note
3 is the denominator of AutoZero uncertainty for the proper
reduction to k=1 for a rectangular distribution assigned tostability uncertainties.

3.2.29.6 Delivered Pressure Uncertainty
Delivered pressure uncertainty is measured uncertainty defined in Section
3.2.1.2.1 combined with control settings. If in dynamic control mode theadditional uncertainty that is combined is equal to the hold limit. When in static
control mode the uncertainty is the current pressure stability in pressure units per
second multiplied by the update rate of the PPC4.
222
P × UpdateRateU 
U del = 2 ×  meas  +  HL  or  Stab
 
2
3
12  
where:
Udel :

Delivered pressure uncertainty.

HL:

Dynamic mode hold limit.

PStab :

Current pressure stability.

UpdateRate : Fixed value in seconds.

Note
The denominator of the dynamic mode uncertainty component
is divided by the
3 because it is considered to be arectangular distribution. The denominator for the static control
uncertainty component is divided by the 12 because it also is arectangular distribution but represents a full width interval.

3.2.29.7 Using Values Other Than Default
The default values of the uncertainty components represent typical pressure
measurement uncertainty specifications (see Section 1.2.2.1). These values are
based on all Q-RPT based product lines with a confidence of 95%. This means
that, taken individually, there is a good chance that the uncertainty of a given
Q-PRT is lower than default. All values represented in Table 13 can be modified
in the product.

 Caution
There are multiple components that make up the productuncertainty portion of the uncertainty function.
It isrecommended that Technical Note 8050TN11 be used for
guidance.
 OPERATION
Uncertainty not available in Basic Interface, see Remote, Section 6.5.4, PRR Command
For Advanced Interface, see Section 7.2.7.3.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Notes:

Page 58

4. BASIC USER INTERFACE

4.

Basic User Interface

4.1

Main Run Screen

The PPC4 Main Run Screen is its home display that is reached on power-up and from which otherfunctions and menus are accessed. It is the very top level of all menu structures.
The Main Run Screen is where the operator works with PPC4 to set and read pressures.
It provides complete information on the system’s current configuration and operating status.
Figure 9 and its legend table summarize the Basic PPC4 Main Run Screen fields and their functions.

Note• from the Main Run Screen to access all menu selections in the Basic
Interface.

•

PPC4 has a screen saver function which causes the display to dim if no key
is pressed for 10 minutes. Pressing a key restores full power to thedisplay. The screen saver time can be changed or screen saving can becompletely suppressed (see Section 3.2.26.1).

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PPC4™ OPERATION AND MAINTENANCE MANUALPRESSURE1UNITM hzRRH
TPRESSURE2 CCDISPLAY FIELD

NAME

1. PRESSURE1

Measuredpressure

PURPOSE
Displays pressure
measured by active
Q-RPT

CONTENTS
Numerical pressure
value and sign

SECTION
1.2.2.1
1.2.2.2
3.2.12

2. UNIT

Unit ofmeasureIdentifies pressure
unit of measure inwhich PRESSURE1
and PRESSURE2
are displayed

Pressure unit ofmeasure abbreviation

3.2.103. M

Measurement
mode

Identifies
measurement modeof displayed pressure<a>:absolute

3.2.11<g>:gauge ornegative gauge

Headpressure
indicator

Indicates whether afluid head correction
is applied to
PRESSURE1<h>:the fluid headis not zero

AutoZeroindicator

Indicates whether
the AutoZero
function is ON or
OFF

<z>:

6. RRH

Active QRPT positionindicator

Indicates the positionof the active utility
sensor or Q-RPT in
the PPC4 system<IH>: Internal Hi<IuH>: Internal Hi(utility sensor)<X1H>: External Hi<X1L>: External Lo

3.2.5

78. CC

Pressurecontrol
indicator

Indicates type ofpressure control,
whether control iscurrently active andwhether custom
control limits are in use<D>: Control mode is
dynamic<S>: Control mode isstatic

3.2.2

4. h

5. z

3.2.16<blank>: fluid head is
zero
AutoZ is ON

3.2.22<blank>: AutoZ is OFF

3.2.13<C> is appended to the<D> or <S> if control
limits are custom
Control character(s)flash if PPC4 is actively
controlling

8. TPRESSURE2

Pressure
information
indicatior

Pressure indication
depending on current
PPC4 function.
Leading character
identifies the value.

<R>: Pressure rate ofchange in current
pressure unit/second<T>: Pressure control
target<D>: Deviation from thepressure control
targetFigure 9. Main Run Screen Display Fields

Page 60

3.2.12

4. BASIC USER INTERFACE

4.2

Keypad and Controls

 THE FUNCTION/DATA KEYS ALLOW VERY COMMONLY USED THE MENU/DATA KEYS PROVIDE ACCESS TO FUNCTIONFUNCTIONS TO BE ACCESSED DIRECTLY BY A SINGLE
KEYSTROKE WHEN PRESSED FROM THE MAIN RUN

MENUS WHEN PRESSED FROM THE MAIN RUN SCREEN.

SCREEN.

 DIRECT PRESSURE CONTROL KEYS
Figure 10. Basic PPC4 Keypad Layout

4.2.1

Set Pressure Automatically PURPOSE
To use the automated pressure control functions of PPC4 to set and maintain target pressure
values.
 OPERATIONTo set a pressure,  from the Main Run Screen. The display is:1.

Standard Main Run Screen first line showing measured
pressure and active Q-RPT.

2.

Edit field for the pressure control target pressure.

100.006 kPa g
Target:100.0

IH

Edit the target pressure value as desired (see Section 0 for information on zero pressurecommands).

Note
To edit numbers with the Basic Interface, use  and  for cursor
position. Use  and  to decrease/increase digit values or enter “.” orspace.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

 to initiate pressure control to the target pressure and return to the Main Run Screen. The
Main Run Screen when pressure control is active is:1.

Standard Main Run Screen first line showing measured
pressure and active Q-RPT. Shows target pressure value
when condition is Ready.

2.

Current control mode indicator. Flashes when automatedpressure control is active. Character is <D> for dynamic
control, <S> for static control. <C> is appended if custom
control parameters are in use.

3.

500.000
D 0.002

kPa a
D

IH

Current deviation from the target pressure (<D>) when in
dynamic control mode and condition is Ready. Target
pressure value (<T>) when controlling and condition is Not
Ready. Pressure rate of change <R> when in static control
mode and waiting for stability.

Observe the Ready/Not Ready indicator LED (see Section 3.2.3) for indication of when thecontrolled pressure has reached the target and stabilized. PPC4 continues controlling
following static or dynamic control operation protocol (see Section 3.2.2) until automatedpressure control is interrupted.

4.2.1.1

Interrupting Automated Pressure Control

Automated pressure control is interrupted by:•

: Suspends control and remains in Main Run Screen. Does not ventpressure. PPC4 passively measures the pressure applied to its TEST(+)
port.

•

Pressing any direct pressure control key other than the jog keys (seeSection 3.2.20): Suspends control and executes direct pressure control.

•

Pressing any function key: Suspends control and goes to the selectedfunction. Does not vent pressure. PPC4 passively measures the pressure.

•: Suspends control and goes to ENTER target pressure value screen.
Does not vent pressure. PPC4 passively measures the pressure applied to its
TEST(+) port.

To resume automated pressure control,  and ENTER a target pressure value.

4.2.1.2

Automated Pressure Commands for Zero
Pressure

Zero in
gauge
mode:

A command for automated pressure control to a target value of zero when ingauge or negative gauge measurement mode is interpreted in the samemanner as if  had been pressed (see Section 3.2.14). A Ready condition
occurs when the vent sequence has completed, including running AutoZ ifapplicable (see Section 3.2.22).

Zero inabsolute
mode:

In response to a command for automatic pressure control to a target value ofzero when in absolute measurement mode, PPC4 opens its down control valves
fully to the EXHAUST port allowing the vacuum source connected to the
EXHAUST port to pull down the pressure as far as possible (see Figure 31). The
down valves stay open until another pressure command is given or control isaborted.
Note
The ultimate pressure achieved by the PPC4 and thesystem connected to the PPC4 TEST(+) depends on thevacuum pump, the pump connections, the volume
connected to the TEST(+) port and PPC4 internal
restrictions.
A Ready condition occurs when the pressure control stability limit is reached (seeSection 3.2.3).

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4. BASIC USER INTERFACE

4.2.2

Vent

 PURPOSE
 activates a sequence to bring the test pressure to atmosphere (see Section 3.2.14).
 OPERATION causes PPC4 to control pressure to near atmospheric pressure and then open thesystem vent valve (see Figure 31 andFigure 32). On-going execution of the vent function isindicated by lighting a RED LED to the left of the  key. Completion of the vent process isindicated by the Ready/Not Ready indicator light becoming GREEN with the vent RED LED
still lighted. The vent valve remains open until  is pressed again, another direct pressure
control key is pressed, or an automated pressure control command is given.

4.3

Basic Interface menus
4.3.1

Main Menu TreeNote
 to access the Main Menu tree from the Main Run Screen.
MENU SELECTIONSEE
SECTION<Setup>, <Range>, <Save/Delete/Delete All>

4.4.1

<Setup>, <Res>

4.4.2<Setup>, <Jog>

4.4.3<Setup>, <UL>

4.4.4

<Setup>, <Control>, <Limits>

4.4.5.1<Setup>, <Control>, <Mode>, <Dynamic/Static>

4.4.5<Setup>, <Drv>

4.4.6<Spec>, <AutoZ>, <On-Off/View/Edit/Run>

4.5.1<Spec>, <Remote>, <COM1/COM2/IEEE488/Format/RS232Test/Ethernet>

4.5.2<Spec>, <Head>, <in/cm>

4.5.3<Spec>, <Reset>, <Sets/Units/Cal/All>

4.5.4<Spec>, <Pref>, <ScrSvr>

4.5.5.1<Spec>, <Pref>, <Sound>, <None/Lo/Mid/Hi>

4.5.5.2<Spec>, <Pref>, <Time>, <Time/Date>

4.5.5.3<Spec>, <Pref>, <ID>, <View/Edit>

4.5.5.4<Spec>, <Pref>, <Level>, <Change User Level/ Edit Password >4.5.5.5<Spec>, <Punit>, <SI/Other/Altitude/User>

4.5.6<Spec>, <Internal>, <Config>

4.5.7.1<Spec>, <Internal>, <Control Ref>

4.5.7.2<Spec>, <Internal>, <Baro>

4.5.7.3<Spec>, <Internal>, <Purge>, <Enable purge>

4.5.7.4<Spec>, <Internal>, <Lo Vnt>,

4.5.7.5
7.2<Spec>, <Cal>, <Hi RPT>, <View/Edit>

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PPC4™ OPERATION AND MAINTENANCE MANUALMENU SELECTION

4.4

SEE
SECTION<Spec>, <Cal>, <Lo RPT>, <View/Edit>

7.2<Spec>, <Cal>, <Barometer>, <View/Edit>

7.3<Spec>, <Log>

4.5.9<ARange>, <Abs/Gage/Neg Gage>

4.5.10<Leak>, <Run/View>

4.5.11<RPT>

4.5.12<Unit>

4.5.13<Range>4.5.14<Mode>, <Abs/Gage/Neg Gage>

4.5.15<Head>

4.5.16<Purge>4.5.17

Menu Tree Operation

 PURPOSE

Note from the Main Run Screen to access all menu selections in the Basic Interface.
<Setup> accesses a menu of functions and features commonly used in setting up and using PPC4.

4.4.1


<Setup>, <Range>

PURPOSE

Save AutoRange ranges and associated settings for recall. Delete previously saved
AutoRange ranges.

4.4.1.1

Saving An AutoRanged Range

 OPERATION
To save a range created by AutoRange, the range must be the active range.
Use AutoRange to create the range (see Sections 3.2.9 and 4.5.10) and thenmake any desired feature and setting adjustments.
Once the AutoRanged range is set up as desired, use <Setup>, <Range>, <Save>.
The display is:1.

Indication that this is an AutoRange range tobe saved.

2.

Designator and position of the Q-RPT used by
the range to be saved.

3.

Pressure unit of measure of the range to be
saved.

4.

Full scale pressure of the range to be saved ingauge mode and absolute mode if available.

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Save range A700K X1H
kPa + 300g/100a

4. BASIC USER INTERFACE to save the range or  to return to the Main Run Screen without saving therange.

4.4.1.2

Deleting AutoRange Ranges

 OPERATION
To delete a single saved AutoRange range, use <Setup>, <Range>, <Delete>.
If there are any saved ranges available to delete, the display is:1.

Indication that the cursor control keys may be
used to toggle through the saved ranges toselect the one to be deleted.

2.

Designator and position of the Q-RPT used by
the range to be deleted.

3.

Pressure unit of measure of the range to bedeleted.

4.

Full scale pressure of the range to be deleted
in gauge mode and absolute mode if available.

< and > A700K X1H
kPa + 300g/100a

Use the cursor control keys to toggle through the ranges available to be deleted.
When the desired range to be deleted is displayed, . If you are sure you want todelete this range, again in response to the <Delete?> query. to returnto the AutoRange screen without deleting a range.
To delete all of the saved AutoRange ranges, press <Setup>, <Range>,<Delete All>. If you are sure you want to delete all the ranges, respond <Yes>
to the <Delete all saved ranges?> query. If not, respond <No>.

4.4.2<Setup>, <Res> (Resolution)

 PURPOSE
To set the resolution with which measured pressures and other pressure indications andsettings are displayed (see Section 3.2.19).
 OPERATION
To access the resolution function, select <Setup>, <Res>.
display is:

The

Display resltn:
IH
0.0010 %FS< and >

Use the cursor control keys to set the desired level of resolution. to return to the Main
Run Screen with the new resolution setting active or to make no changes.

4.4.3<Setup>, <Jog>

 PURPOSE
Adjust the nominal change in pressure caused by using the jog direct pressure control keys
( and ) (see Section 3.2.20).
 OPERATION
To access the jog step adjustment function, select <Setup>, <Jog>.
The display is:

Jog step size:
0.020 kPa

IH

Edit the value of the jog step as desired.  to return to the Main Run Screen with the newjog step size active.  to return to the Main Run Screen with no change to the jog step
size.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

4.4.4<Setup>, <UL> (Upper Limit) PURPOSE
To set the upper and lower limit pressure value for a pressure range and measurement mode(see Section 3.2.21).
 OPERATION
To view or edit upper and lower limits use <Setup>, <UL>.
If the current measurement mode is absolute or gauge, there is an upper limit only.
The display is:1.

Entry field for upper limit value in active pressure unit ofmeasure and measurement mode.

Upper limit:
204.000 kPa a

IH

Edit the upper limit value as desired. The maximum upper limit is 105 % of AutoRange range
or 102 % of default Q-RPT range, whichever is smaller.  to return to the Main Run
Screen with the new upper limit active.  to return to the Main Run Screen with no change
to the upper limit.
If the current measurement mode is negative gauge or the Q-RPT is a BA100K, there is also alower limit. The display is:1.

Entry field for upper limit value.

2.

Entry field for lower limit value and active range pressure unitof measure and measurement mode indication.

Upper:104.00
Lower:-110.00

IH
kPa g

Edit the upper and lower limit values as desired. Use the cursor control keys to move
between the two edit fields. The lower limit must be a negative value.  to return to theMain Run Screen with the new upper and/or lower limit active.  to return to the Main Run
Screen with no change to the limits.
When the upper or lower limit has been exceeded, the display of current pressure flashes
and a buzzer sounds for 3 seconds at 2 second intervals. Reduce pressure using directpressure control keys or an automated pressure command to return to normal operation.

Note
Upper limit values are specific to each range and measurement mode. Be
careful not to assume that the upper limit set in one measurement mode
will apply to the other.
For example, if you set 150 kPa as the upper limit in gauge mode, theupper limit will not be 150 kPa in negative gauge mode of the same range.

4.4.4.1

Over Pressure Function

In addition to the UL function, PPC4 has an over pressure function (see Section
3.2.21.1).
To recover from an overpressure condition, correct the overpressure conditionand cycle PPC4 power. Be sure to correct the condition that caused theoverpressure before cycling power.

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4. BASIC USER INTERFACE

4.4.5<Setup>, <Control> PURPOSE
To set the automated pressure control mode for the active range, customize control
parameters, activate default control parameters.
 OPERATION
To access the CONTROL function, use <Setup>,<Control>. The display is:

Dynamic♦Limits ♦Mode

X1H<Limits> to view or edit the current control limits (see Section 4.4.5.1).
<Mode> to change the control mode and to reset custom control parameters (see Section
4.4.5.2).
Control Mode:
X1H♦Dynamic ♦Static

The display is:

The cursor is on the active control mode. Making a control mode selection activates thecontrol mode, sets default control parameters and returns to the Main Run Screen. To set
custom control parameters, use <Setup>, <Control>, <Limits> from the Main Run Screen(see Section 3.2.13).

4.4.5.1<Limits> (Custom Control Parameters) PURPOSE
To view active pressure control parameters and/or set custom control
parameters.
 OPERATION
To view active control parameters and/or set custom control parameters, select<Setup>, <Control>, <Limits> from the Main Run Screen. The display is:1.

Active Q-RPT designator.

2.

View/edit field of hold limit value in active
pressure unit of measure. Shows active holdlimit.

3.

Active control mode (<D> for dynamic, <S> forstatic).

Hold Limit:
0.05
kPa

X1H
D

Edit the hold limit value if desired and  to view the stability.
The next display is:1.

Active Q-RPT designator.

2.

View/edit field of stability limit value in active
pressure unit of measure. Shows active
stability limit.

3.

Active control<S> for static).

mode

(<D>

for

Stability Limit: X1H
0.05
kPa/s
D

dynamic,

Edit the stability limit value if desired and  to return to the Main Run Screenwith the edited values active.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

4.4.5.2

Turning-Off Custom Control Parameters

To return to default pressure control parameters for the active range and control
mode, reselect the control mode using <Setup>, <Control>, <Mode> (seeSection 3.2.13).

4.4.6<Setup>, <Drv> (Drivers)

 PURPOSE
To control the output signals of PPC4’s 8 channel, 12 V external drivers (see Section 3.2.23).
 OPERATION
To access the driver control function use <Setup>,<Drv>. The display is:External Drivers: 1
2 3 4 5 6 7 8

 or  allows navigation between valve driver numbers.  turns that driver ON and
OFF. An active driver is indicated by <*> immediately following the driver number.

 Caution
The PPC4 PURGE function makes use of the valve driver option. Valve
driver number 8 is used to actuate the SPLT exhaust valve. The SPLT
exhaust valve is actuated when performing the PURGE function and in the
background every time the PPC4 VENT function is used. When making useof valve drivers, note that when the PURGE function is enabled, valve
driver number 8 will be actuated independently of user initiated valve
driver commands (see Section 3.2.27.4).

4.5<Spec> (Special)Note from the Main Run Screen to access all menu selections in the Basic Interface.

 PURPOSE<Spec> accesses a menu of PPC4 functions and features that are less commonly used or not normallyused in regular operation.
 OPERATION<Spec> from the Main Menu screen to access the menu. The
display is:♦AutoZ ♦Remote ♦Head♦Reset ♦Pref ♦Punit♦Internal ♦Cal ♦Log

Note
Some screens, such as the SPECIAL menu, go beyond the two lines provided by thedisplay. This is indicated by a flashing arrow in the second line of the display.
Press the cursor control keys to move the cursor to access the lines that are notvisible.

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4. BASIC USER INTERFACESPECIAL menu choices include:<AutoZ>Manage AutoZero function for the active Q-RPT or utility sensor (see Section 4.5.4.1).

<Remote>View and edit PPC4 COM port (RS232) and IEEE-488 or Ethernet interface settings (seeSection 4.5.4.2).

<Head>Set HEAD function fluid and height unit of measure (see Section 4.5.4.3).

<Reset>Access PPC4’s various reset functions (see Section 4.5.4.4).

<Pref>

View and set screen saver time, keypad sound frequency, unit ID number, time/date,security protection level (see Section 4.5.5).

<Punit>Customize the <Unit> key pressure unit of selections (see Section 4.5.6).

<Internal>

Access internal functions including control configuration, control reference, on-board
barometer viewing, and purge function ON/OFF, direct control of Q-RPT Lo Vent valves(see Section 4.5.7).

<Cal>

View and adjust PPC4 utility sensor, Q-RPT and barometer calibration coefficients(see Section 4.5.8, 7.2, 7.3 and 7.4).

<Log>

View the PPC4 incident log (see Section 4.5.9).

4.5.1<Spec>, <AutoZ>

 PURPOSE
To offset the PPC4 system Q-RPTs relative to a reference value in order to compensate forpossible changes in Q-RPT zero between full recalibrations (see Section 3.2.22).
 OPERATION
To access the PPC4 AutoZ function menu use <Spec>, <AutoZ>. The display is:•1.

Active Q-RPT designator.

2.

Indication of active measurement mode (abs for absolute,
gage for gauge and negative gauge).

3.

Indication of whether AutoZ is currently ON or OFF for thisQ-RPT and measurement mode.

♦Off ♦View♦Edit ♦Run

IH
abs ON<Off> (or <On>) to change the AutoZ status for the current Q-RPT and measurementmode from ON to OFF or vice versa.

Note
AutoZ ON is indicated by a <z> in the Main Run Screen, top line, fourthcharacter from the right. When AutoZ is OFF, the character is blank.
•<View> to view the current value of Poffset for the active Q-RPT and measurement mode.

•<Edit> to edit the value of Poffset for the active Q-RPT and measurement mode (seeSection 4.5.1.1).

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PPC4™ OPERATION AND MAINTENANCE MANUAL•<Run> to run the AutoZ routine which determines and activates Poffset relative to Pstd,0(see Section 4.5.1.2). <Run> is only applicable to Axxx (absolute) Q-RPTs in absolutemeasurement mode. AutoZ is run automatically without operator intervention in gauge
and negative gauge measurement modes whenever PPC4 is in the VENT condition (seeSection 3.2.14).

4.5.1.1

Edit AutoZ

To edit the current Poffset value for the active Q-RPT and measurement mode,press <Spec>, <AutoZ>, <Edit>. The display is:

1.

<Abs> for absolute, <Gage> for gauge andnegative gauge.

2.

Active Q-RPT for which Poffset is being viewed.

3.

Edit field for value of Poffset.

Poffset,abs
8.4
Pa

Edit Poffset as desired and  to activate the new value.
changes.

4.5.1.2

X1H

 to abandon

Run AutoZ

Run AutoZ is the function by which the current Q-RPT reading is compared to areference, Pstd,0, at atmospheric pressure to determine a new value of Poffset.
The value of Poffset is then used by AutoZ to automatically correct the Q-RPT for
possible change in zero (see Section 3.2.22).
To access run AutoZ, press <Spec>, <AutoZ>, <Run>. If the current
measurement mode is gauge, a message indicating that AutoZ cannot be run
manually in gauge mode is displayed.
If the current measurement mode is absolute, the display is:1.

Real time reading (without head correction),pressure unit of measure and measurementmode of the active Q-RPT.

2.

Active Q-RPT position designator.

3.

Entry field for the value of Pstd,0 in the current
pressure unit of measure.

96.7755 kPa a z X1H
Pstd,0: 0.00000

Enter the value of the AutoZ reference (Pstd,0) in the same unit of measure as
the top line display and . PPC4 logs the readings and calculates a new
AutoZ offset value. The next display is:
Press [ENTER] to activate the new valueof Poffset or  to start over with entry of a
new AutoZ reference (Pstd,0) value.

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Old Poffset: 0
New Poffset: 8PaPa

4. BASIC USER INTERFACE

4.5.2<Spec>, <Remote> PURPOSE
To configure the PPC4 COM1, COM2 and IEEE-488 (GPIB) or Ethernet communication
ports. To test COM1 and COM2 communications. To select remote programming
communications format (see Sections 3.2.24 and Section 6.3.1).
 OPERATION
To access the communications settings, select <Spec>, <Remote>.
Choice include:<COM1>

To view and edit COM1 settings (see Section 4.5.2.1).

<COM2>

To view and edit COM2 settings (see Section 4.5.2.1).

<IEEE>

To view and edit IEEE-488 settings (see Section 4.5.2.2).

<Format>To select remote programming command format (see Section 4.5.2.3).

<RS232test>

To run the COM1 and COM2 communications test (see Section 4.5.2.4).

<Ethernet>

To view and edit LAN (Ethernet) settings (see section 4.5.2.5).

4.5.2.1<COM1> and <COM2>

The COMx ports can be set for specific communications settings. The settings
are baud rate, parity, data bits and stop bits. The available options are:Baud

1 200, 2 400, 4 800, 9 600, 19 200

ParityNone, Odd or Even

Length7 or 8Stop Bit

1 or 2The default is <2400, E, 7, 1> for both COM1 and COM2.
The user can also specify one or two termination characters as well as define
these characters. These are referred to as “Term1” and “Term2”. These define
the characters that mark the end of commands that are sent to the PPC4. The
PPC4 looks for an ASCII(13) (carriage return) to terminate a received command
but responds with both and ASCII(13) (carriage return) and an ASCII(10) (linefeed). There are no other options.

4.5.2.2<IEEE-488>

The IEEE-488 port’s primary address can be set from 1 to 31 in this screen. The factory
default value is 10. Secondary addressing is not used or supported. This address
must not conflict with the address of any other device on the same IEEE-488 bus.
The receiving terminating character must be a line feed and EOI. Carriage returns
are ignored if received. The PPC4 sends a line feed and asserts the EOI line toterminate a reply. These settings are fixed to agree with IEEE Std. 488.2. If youchange the address, the IEEE interface will reset (PON) and become idle.

4.5.2.3<Format><Spec>, <Remote>, <Format> allows the remote program command syntax tobe selected. The cursor is on the active format. Select <Classic> to activate theclassic command format or <Enhanced> for the enhanced format.
Selecting a format resets the IEEE-488 interface and puts it into an idle state.
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PPC4™ OPERATION AND MAINTENANCE MANUAL

4.5.2.4<RS232test>

The RS232 self-test is provided to check the PPC4 COM ports and the interface
cable independently of an external device or computer.
If you are having difficulty communicating with PPC4 from a host computer
using RS232, the RS232 self test can help establish that the PPC4 COM1 port
you are trying to communicate with and the interface cable you are using are good.
To run a self test of the RS232 ports (COM1 and COM2), press <Spec>,<Remote>, <RS232test>.
The display prompts you to connect COM1 to COM2 using a standard pin-to-pin
DB-9F to DB-9M RS232 cable (see Section 6.3.1.1).
Once the cable has been installed,  to run the self-test. The test is first
executed in the COM1→COM2 direction and then in the COM2→COM1 direction.
If the COM1→COM2 test passes: <PASSED> displays briefly and the test
proceeds to COM2→COM1.
If COM2→COM1 passes: <PASSED> is displayed briefly followed by theconclusion, <The RS232 test has PASSED>.
If a test fails: Execution is suspended until  is pressed.

Note•

The PPC4 RS232 test can fail for three reasons:•

The RS232 cable being used is incorrect (see Section
6.3.1.1 for information on the correct cable).

•

COM1 and COM2 do NOT have the same serial
communications settings and cannot communicate (seeSection 4.5.2.1 to set the COM ports).

•

COM1 or COM2 is defective.

•

The reason for failed communications is almost always acable or incorrect RS232 interface settings. Be sure thatthese are correct before concluding that a COM port isdefective.

4.5.2.5<Ethernet>

 PURPOSE<Spec>, <Remote>, <Ethernet> allows settings that pertain to the Ethernet
connection (optional). DHCP (Dynamic Host Configuration Protocol) determines
how an IP address will be provided: With DHCP “On” the IP address is provided
by the LAN (Local Area Network). With DHCP “Off” the IP address is provided
manually.
DHCP

On, Off

Addr

IP address (1xx.xxx.xxx.xxx) where x is 0-9

To enter an IP address in static mode (i.e. DHCP=Off): or  to toggle between 0 and 5
 and  to increase/decrease by 1
 and  select which digit to edit.

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4. BASIC USER INTERFACE to accept IP address and display the PPC4 MAC (Media Access Control)
address. This value is unique to each PPC4 and is contained in the Ethernet
module of the PPC4 if the Ethernet option is selected.

4.5.3<Spec>, <Head> PURPOSE
To view or change the properties of the fluid Head function (see Section 3.2.16) including theunit of measure of length for head height entry and the test gas species for density
calculations.
 OPERATION
From the Main Menu screen, press <Spec>, <Head>.
Select the desired height unit of measure and .
Select the type of gas that is being supplied to PPC4 and . The characteristics of the gas
selected will be used by PPC4 in calculating head pressures.

4.5.4<Spec>, <Reset>

 PURPOSE
To reset various PPC4 settings to default or factory values (see Section 3.2.25).

 Caution
PPC4 reset functions will change current settings to factory defaults.
These may include settings vital to PPC4 operation and affecting thecalibration of the quartz reference pressure transducers (Q-RPTs). Resetfunctions should only be used by qualified personnel with knowledge ofreset consequences. Reset functions should not be used experimentally.
 OPERATION
To access the RESET<Reset>. The display is:menu, press <Spec>,♦Sets ♦Units ♦Cal♦All

RESET menu choices include:<Sets>

to reset general system operating parameters (see Section 4.5.4.1).

<Units>to reset unit of measure functions (see Section 4.5.4.2).

<Cal>

to reset internal calibration coefficients and modes (see Section 4.5.4.3).

<All>

to reset all settings except ID and security password to factory default values(see Section 4.5.4.4).

4.5.4.1<Set>

 PURPOSE
The Reset – Sets resets are itemized in Table 8, Section 3.2.25.1.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

4.5.4.2<Units> PURPOSE
The Reset – Units resets are itemized in Section Section 3.2.25.2.

4.5.4.3<Cal> PURPOSE Caution
The Reset - Cal function will reset Q-RPT, utility sensor andbarometer calibration coefficients and settings and reset AutoZ
values to zero. This will change the PPC4 calibration and could
cause it to make out of tolerance measurements.
The Reset – Cal resets are itemized in Table 9, Section 3.2.25.4.

4.5.4.4<All> PURPOSE Caution
The reset - all function clears and deletes large amounts of user
defined information including critical calibration data.
The Reset – All resets are itemized in Table 10, Section 3.2.25.5.

4.5.5<Spec>, <Prefs> PURPOSE
To access a menu of PPC4 operational preferences and functions.
 OPERATION
To access the PREFS menu press <Spec>, <Pref>.
The display is:♦ScrSvr ♦Sound ♦Time♦ID ♦Level

The PREFS menu includes:<ScrSvr>

View and change the screen saver activation time (see Section 4.5.5.1).

<Sound>View and change the key press sounds (see Section 4.5.5.2).

<Time>

View and edit the internal time and date settings (see Section 4.5.5.3).

<ID>

View the PPC4 serial number (SN) and view or edit the ID number(see Section 4.5.5.4).

<Level>View and set user security level and password (see Section 4.5.5.5).

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4. BASIC USER INTERFACE

4.5.5.1<ScrSvr>

 PURPOSE
To adjust the idle time after which PPC4’s SCREEN SAVER activates (seeSection 3.2.26.1).

Note
Setting screen saver time to zero eliminates the SCREEN SAVER
function so that the display permanently remains at fullbrightness.
 OPERATION
To access the SCREEN SAVER function, use <Spec>, <Pref>, <ScrSvr>. Edit,in minutes, the idle time after which screen saver will activate to dim the screen.
Set the time to zero to eliminate the SCREEN SAVER function.

4.5.5.2<Sound> PURPOSE
To adjust or suppress the PPC4 key press sound (see Section 3.2.26.2).
 OPERATION
To access the keypad sound adjustment function use <Spec>, <Pref>,<Sound>.
<Lo>, <Mid> or <Hi> to adjust the valid key press tone frequency.
<None> to suppress the key press tone.

4.5.5.3<Time>

 PURPOSE
To view and edit the PPC4 internal time and date settings (see Section 3.2.26.3).
 OPERATION
To
accessthe
TIME
use<Spec>,<Pref>,The display is:function<Time>.

Edit: ♦Time ♦Date
08:32:11am 20080325<Time> to edit the time. Edit hours, then minutes, then am/pm by using after each entry. Seconds go to zero when minutes are entered. This can beused to synchronize the time with a time standard.
<Date> to edit the date. The date must be specified in YYYYMMDD format.

4.5.5.4<ID>

 PURPOSE
To view or edit the PPC4 user ID and to view the PPC4 serial number (seeSection 3.2.27.1).

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PPC4™ OPERATION AND MAINTENANCE MANUAL OPERATION
To
accesstheIDfunction<View> to view the current ID.

use<Spec>,<Pref>,<ID>.

<Edit> to edit the ID.
The ID has twelve characters. When the edit screen is opened, the cursor is on
the first character. Numerical values can be entered directly from the keypad. In
addition, the cursor control keys can be used to toggle through a list of available
alpha numeric characters. Holding the key slews through the characters.
Character order going up is: blank space, symbols, lower case letters, upper
case letters, and numbers. After selecting a character,  to activate it andmove to the next character field.
When a character is selected the cursor moves to the next character. To leave a
blank character,  with the field for that character blank. Use this for the
trailing characters if the ID being entered is less than twelve characters.
After the last of the twelve characters has been entered, the <Save ID?> option is offered.
<No> to return to the ID edit screen. <Yes> to save the edited ID.

Note
The ID can be set remotely from a computer which is moreconvenient than entering characters from the keyboard (seeSection 6.5.4, ID command). The ID is not cleared or reset by
any RESET function (see Section 3.2.25).

4.5.5.5<Level> (Security) PURPOSE
To set user protection levels to restrict access to certain functions and to edit the
password required for changing user levels. The security levels are structured tosupport typical levels of operation as shown in Table 12, Section 3.2.26.4.
 OPERATION
PPC4 is delivered with no active password and access to the User Level menu is open.
The user level is set to low. User levels can be changed freely until a password has
been created.
To
access
the
LEVEL
use
<Spec>,<Pref>,The display is:function<Level>.

<Change user level> brings up the
restriction menu:♦Change user level♦Edit password
Restrictions:♦Disable ♦Enable

The cursor is on the current restriction level.
or  back to the Main Run Screen.
If no password is active, <Edit
password> displays the user password
and allows it to be edited.

Select a different level or

Password: pppppp
0 disables password

 Caution
Once a password has been entered, the user level cannot bechanged without reentering the password.
Passwords can be up to six numbers in length and cannot start with a zero.
If <0> is entered, the password is made inactive and the user will not be required
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4. BASIC USER INTERFACE

to enter a password to access the user level menu.
security level of <Lo>, is the factory default.
If there is an active password, the
PPC4 password entry screen appears.
The user must enter the user definedpassword or the factory secondary
password to proceed further:

This condition, with a

SN: nnXXXX
Password: pppppp

The first field, <nn>, is the serial number of the PPC4, followed by a second field,<XXXXX> a number that the PPC4 changes each time the secondary password is used.
The third field, <pppppp> is for user entry of the normal password.

Note
The factory secondary password is available in case the user’s
password has been misplaced or forgotten. It can be obtainedby contacting a DHI Authorized Service Center (see Table 31).
The factory secondary password is different for all PPC4’s andchanges each time it is used.

4.5.6<Spec>, <Punit> PURPOSE
To customize the selection of pressure units of measure.
 OPERATION
From the Main Run Screen press <Spec>, <Punit>. The display is:1.

Entry field to specify which unit position (1 – 6) of the<Spec>, <Punit> function key menu is to be changed.

Enter the number of the unit position that you would
like to change. The display becomes:

Set up unit #6

IH

Unit#6 ♦SI ♦Other♦Altitude ♦User

Select the desired pressure unit category (SI units include units based on SI such as mmHg),
then select the desired unit from the unit menu.
The units of measure available are listed in Table 14.
Table 14. Unit Function - Available Units of Measure<SI><Other><Altitude>

<Pa>
<hPa>
<kPa>
<MPa>
<mbar><bar><mmHg><mmWa><psi><psf><inHg><inWa><kcm2><Torr><mTor><feet><meters><User>

Note
If the pressure unit selected represents a water column (inWa, mmWa,
mWa) (inches/millimeters/meters of water), the reference temperature
for water density must we specified in a separate menu (choices are
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PPC4™ OPERATION AND MAINTENANCE MANUAL

4 ºC, 20 ºC 60 ºF).
If <User> is selected, the user unit must be defined. The display is:1.

Define user unit:
1.000000 unit/Pa

Entry field.

Enter the number of user units per Pascal (Pa) in the entry field.  defines the user unit
and returns to the <Set up unit #n> screen.

4.5.7<Spec>, <Internal>

 PURPOSE
To view, set, adjust, and maintain various aspects of PPC4’s internal operation (see Section
3.2.27).
 OPERATION
To access the internal selections use <Spec>,<Internal>. The display is:♦Config ♦Control Ref♦Baro ♦Purge ♦Lo Vnt

The INTERNAL menu choices include:<Config>

To run an automated routine that readjusts internal pressure control
coefficients (see Section 4.5.7.1).

<Control Ref>

To view or manually set the EXHAUST port condition (see Section 4.5.7.2).

<Baro>

View the real time output of the on-board barometer, if present(see Section 4.5.7.3).

<Purge>Turn the automated purging function ON and OFF (see Section 4.5.7.4).

<Lo Vnt>

Operate Q-RPT module Gxxx and BGxxx TEST (-) Vent valve directly(see Section 4.5.7.5).

4.5.7.1<Config>

 PURPOSE
To run an automated routine that readjusts internal pressure control coefficients.
This function is considered part of PPC4 maintenance and is therefore coveredin the maintenance section of this manual (see Section 7.5).
 OPERATIONThis function is considered part of PPC4 maintenance and is therefore coveredin the maintenance section of this manual (see Section 7.5.1).

4.5.7.2<Control Ref>

 PURPOSE
To specify whether PPC4 should automatically determine whether a vacuum
source or atmospheric pressure is connected to its EXHAUST port or to
manually set the EXHAUST port condition (see Section 3.2.27.1).

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4. BASIC USER INTERFACE

 OPERATION
To access the CONTROL REFERENCE
functionuse<Spec>,<Internal>,<Control Ref>. The display is:

Control Ref: ♦Auto♦Vac ♦Atm ♦View

Select:<Auto>To set the PPC4 to determine the EXHAUST port condition
automatically using its internal exhaust sensor. This is the normal
Control Ref setting.

<Vac>

To set the PPC4 to assume that a vacuum supply is connected to
the EXHAUST port.

<Atm>

To set the PPC4 to assume that the EXHAUST port is open toatmospheric pressure.

<View>

To view the current EXHAUST port condition assumed by PPC4 andhow it was determined.

4.5.7.3<Baro>

 PURPOSE
To view the value of atmospheric pressure as measured by the PPC4 on-board
barometer (see Section 3.2.27.3).
 OPERATIONNote
PPC4s that have Gxxx Q-RPTs (no Axxx, BGxxx or utility
sensor) are NOT equipped with an on-board barometer.
To view the current reading of the on-board barometer use <Spec>, <Internal>,<Baro>.
The display is in the active pressure unit of measure(see Section 3.2.10).

4.5.7.4<Purge> PURPOSE
To enable and disable the PURGE function which automates the use of theoptional Self Purging Liquid Trap (SPLT) (see Section 3.2.17).
 OPERATION
To access the purge enable/disable function use <Spec>, <Internal>, <Purge>.
<Yes> to enable purge or <No> to disable purge.

 Caution
When the purge function is enabled, PPC4 makes backgrounduse of valve driver channel #8 independently of user actions(see Sections 3.2.17, Section 3.2.23).

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PPC4™ OPERATION AND MAINTENANCE MANUAL

4.5.7.5<Lo Vnt>

 PURPOSE
To cause a PPC4 or external RPM4’s Gxxx or BGxxx Q-RPT TEST (-) vent valve
to stay open or closed rather than open and close automatically (see Section
3.2.27.5).

NoteThis feature is active only when the active Q-RPT is a Gxxx
(gauge) or BGxxx (bi-directional gauge) Q-RPT.
 OPERATIONNote
The normal setting for the TEST (-) vent valve is <Auto> inwhich PPC4 automatically controls the valve based on current
PPC4 operation. Settings other than <Auto> should only be
selected by advanced users.
To access the LO VNT function use <Spec>, <Internal>, <lo vent>. If a Gxxx
(gauge) or BGxxx (bi-directional gauge) Q-RPT is not active, the display is:<Available with Gxxx or BGxxx Q-RPT only>.
If a Gxxx or BGxxx Q-RPT is active, thedisplay is:

TEST (-) Vent:♦Auto♦Open ♦Close ♦View<Auto> for the TEST (-) vent valve operation to be controlled automatically by
PPC4 based on current operation. This is the default and recommended setting.
<Open> to cause the TEST (-) valve to open and remain open regardless of
PPC4 operation until the setting is changed.

 Caution
If the PPC4 detects a condition in which it determines there could
be a risk of overpressure to the RPT by opening the TEST (-) Vent
valve when a Manual Open is requested, a message indicating a
DP overpressure risk is displayed. If this message is displayed,
return to normal operation, vent the PPC4 and try again.
<Close> to cause the TEST (-) valve to close and remain closed regardless of
PPC4 operation until the <Lo Vnt > setting is changed.
<View> to view the current condition of the TEST (-) valve. The display indicates
whethercurrent
valve
operationiscontrolled
by
the
PPC4
(<Auto TEST (-) vent>) or has been set manually (<Manual TEST (-) vent>)
followed by the current valve status (<Open> or <Close>).

4.5.8<Spec>, <Cal>

 PURPOSE
To calibrate the PPC4 utility sensor, Hi and/or Lo Q-RPTs and adjust the on-board
barometer. This function is considered part of PPC4 maintenance and is therefore coveredin the maintenance section of this manual (see Sections 7.2, 7.3, 7.4).
 OPERATION
See Sections 7.2, 7.3 and 7.4.

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4. BASIC USER INTERFACE

4.5.9<Spec>, <Log>

 PURPOSE
To view and/or clear the PPC4 event log (see Section 3.2.27.5).
 OPERATION
To view the event log press <Spec>, <Log>.
 and  to move back and forth between older and newer log entries.
Each log entry has two screens, one with the event description and one with the even time anddate. and  to toggle between the two screens. The oldest logged event appears.
After the last log has been viewed, the option to clear the log, <No>, <Yes> is presented. <Yes>
to remove all entries from the log. <No> to continue without altering the log.
 to leave the log.

4.5.10<ARange> PURPOSE
To automatically set up PPC4 to optimize its measurement and control characteristics andfeatures to cover a specific pressure range (see Section 3.2.8).
 OPERATION
To use the AutoRange function, press <ARange> from the Main Menu and respond to the
PPC4’s prompts.
Select AutoRange measurement mode: The screen is identical in appearance andfunction to the <Mode> screen (see Section 4.5.15). The choice of measurement modes
offered reflects all the Q-RPT types available (Axxx, Gxxx, BGxxx) in the PPC4 system,
not just the active Q-RPT.
Select pressure unit of measure: The screen is identical in appearance and function to
the <Unit> screen (see Section 4.5.13).
Enter the AutoRange full scale pressure: Enter the full scale pressure value in the<------> entry field and . If the full scale pressure entered cannot be covered by anyof the Q-RPTs available, an error message is displayed. If the full scale pressure can becovered by an available Q-RPT, AutoRange proceeds to the range display.

 Caution
RPM4 with Q-RPT full scale spans below 14 MPa have SDS self defense
system to isolate and protect the Q-RPTs. If an external RPM4 SDS
pressure rating is less than the PPC4 maximum pressure thenAutoRanged ranges greater than the SDS rating are not allowed (seeSections 3.2.5, 6.5.4, 3.2.8). In order to create AutoRanged ranges orgenerate pressures above the SDS pressure rating the RPM4 must be
disconnected or the RPM4 SDS must be upgraded to a higher pressure
rating. Upgrades may be done at the DH Instruments service center (seeTable 36).

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View proposed AutoRange range: The proposed AutoRange range screen is:1.

Indication that this is a screen of the proposed AutoRange range.

2.

Designator and position of the Q-RPT that AutoRange has
selected to cover the AutoRange full scale and measurement
mode.

3.

Pressure unit of measure specified in AutoRange.

4.

AutoRange full scale pressure in gauge mode and absolutemode if available. Shows absolute mode only if AutoRange
measurement mode is absolute and full scale is less than 100
kPa (14.5 psi). Gauge mode only if the Q-RPT is a Gxxx,
BGxxx or Axxx with absolute OFF.

AutoRange A700K X1H
kPa
200g/300a

Accept proposed AutoRange:  to accept the proposed AutoRange and go theMain Run Screen with the AutoRange range active. To modify the AutoRange full scale,measurement mode or pressure unit of measure,  to back up through the AutoRange
screens and make changes.
If you would like to use a Q-RPT other than the one selected by AutoRange, use <RPT> in theMain Menu.. Only Q-RPTs that can cover the specified full scale and measurement mode areshown.  when the desired Q-RPT is displayed.

 Caution
Before operating PPC4 with external Q-RPTs, check carefully that the QRPT TEST(+) port is connected to the PPC4 TEST(+) port. If the external
Q-RPT is NOT connected to the PPC4 TEST(+) port, it will not measure thepressure generated by PPC4 and PPC4 may reach a pressure higher than
the target pressure before its watchdog function recognizes that theexternal RPT is not connected.

4.5.11<Leak>

 PURPOSE
To run an automated leak check routine that determines the leak rate of the system
connected to the PPC4 TEST(+) port (see Section 3.2.18).
 OPERATION
To run a leak check, first set the pressure to the desired leak check pressure using the directpressure control keys (see Section 3.2.1) or automated pressure control (see Section 4.2.1).
To access the LEAK CHECK function, use <Leak> from the Main Menu screen. Select<Run> to run a leak test. The display is:1.

Edit field for the time over which the leak check pressurechange will be measured, in seconds.

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Set leak check time:
15 s

4. BASIC USER INTERFACE

Edit the leak check time if desired (minimum 1, maximum
 again when ready to start the leak test. The leak test display is:1.

Standard Main Run Screen first line showing measured
pressure.

2.

Active RPT position indicator3.

Indication that leak test is running and countdown of timeremaining.

999)

957.84 kPa a
Leak testing

then

.

HI
13 s

 can be used to abort the running leak test.  while the leak test is running restarts theleak check timer. When the leak check timer countdown has completed, the leak check
results screen is displayed:1.

Total pressure change from start to finish of leak check time.

2.

Indicator of RPT used to run leak check.

3.

Average rate of change of pressure over the leak checktime period.

∆P
0.61 kPa a
Rate 0.06 kPa/s

HI

From the leak check results screen,  to repeat the leak test.
 to return to leak check Main Menu and exit to the Main Run Screen.
To view the results of the most recently completed leak check, press <View>. If NO leakcheck data is stored (i.e., if the PPC4 has never run a leak test or a reset has cleared
previous leak test results), the results screen displays <Data not available> briefly andreturns to Main Run Screen.  or  to return to the Main Run Screen.

4.5.12<RPT> PURPOSE
Search for, initialize and display internal and external Q-RPTs available to the PPC4 system(see Section 3.2.5).

 Caution•

Before operating PPC4 with external Q-RPTs, check carefully that the
Q-RPT TEST(+) port is connected to the PPC4 TEST(+) port. If theexternal Q-RPT is NOT connected to the PPC4 TEST(+) port, it will notmeasure the pressure generated by PPC4 and PPC4 may reach apressure higher than the target pressure before its watchdog function
recognizes that the external RPT is not connected.

•

RPM4 with Q-RPT full scale spans below 14 MPa have SDS self
defense system to isolate and protect the Q-RPTs. If an external
RPM4 SDS pressure rating is less than the PPC4 maximum pressurethen a warning will be displayed on the PPC4 front panel when the
RPM4 is detected. In addition, AutoRanged ranges greater than the
SDS rating are not allowed (see Sections 3.2.5, 6.5.4, 3.2.8). In order tocreate AutoRanged ranges or generate pressures above the SDS
pressure rating the RPM4 must be disconnected or the RPM4 SDS
must be upgraded to a higher pressure rating. Upgrades may be doneat the DH Instruments service center (see Table 36).

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PPC4™ OPERATION AND MAINTENANCE MANUAL OPERATION
To run the Q-RPT and utility sensor search and initialize function, select <RPT> from theMain Menu. PPC4 displays <Searching for RPTs…> while it runs the search function.
When the RPT search is complete, the Q-RPTs identification screen is displayed.
1.

IH, and L: Identification of RPTs in Internal (PPC4), Hi and Lo
positions.

2.

X1H and L: Identification of RPTs in External (RPM4), Hi and Lo positions.

IH:A7Mu
X1H:A7M

L:none
L:A700K

The cursor is on the position designator of the active Q-RPT or utility sensor. Use the cursor
control keys to move the cursor to other positions and to view the third line if present.  tomake the selected Q-RPT or utility sensor active in its default range (see Section 3.2.6).
<RPT> again to cause the Q-RPT search to run again.  to return to the Main Run Screen
without making any changes.

4.5.13<Unit>

 PURPOSE
To select the unit of pressure in which PPC4 displays pressure values (see Section 3.2.10).
 OPERATIONTo change the pressure unit of measure for the active
range, use <Unit> from the Main Menu screen while
the range is active. The display is:♦kPa ♦Pa ♦MPa♦hPa ♦bar ♦mbar

The cursor is on the number corresponding to the pressure unit of measure active for the current range.
To change the pressure unit of measure, select the desired unit.
returns to the Main Run Screen with the selected unit active.

4.5.14Making the selection<Range> PURPOSE
To view and/or change the active pressure measurement range and associated settings (seeSection 3.2.9).
 OPERATION<Range> from the Main Menu activates the range viewing and selecting function. When
<Range> is first selected, the range identification screen for the active range is displayed.
For example:
1.

Q-RPT or utility sensor designator.

2.

Type of range. DF for the Q-RPT’s default range; AR for a range
created by AutoRange.

3.

Q-RPT or utility sensor position designator.

4.

Current pressure unit of measure.

5.

Full scale pressure in current unit of measure in gauge and/or
absolute measurement mode depending on type of Q-RPT and range.

Active A700K
DF IH
psi
100g/100a

To select a range to become the active range,  while the desired range is displayed.
PPC4 must be vented for the range change to occur.  if necessary to complete the rangechange.
When selecting a range, if the range’s Q-RPT is an external Q-RPT and the PPC4 cannot
communicate with it, PPC4 displays <Cannot find range’s external Q-RPT (Xn)>.
 or  to return to the range selection screen. For information on setting up andcommunicating with external Q-RPTs see Section Section 2.3.6.

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4. BASIC USER INTERFACE while in the RANGE function returns to the Main Run Screen with no range change
having been made.

4.5.15<Mode>

 PURPOSE
To set the measurement mode (absolute, gauge or negative gauge) for the active range (seeSection 3.2.11).
 OPERATIONTo change the active measurement mode for a range,use <Mode> from the Main Menu screen while therange is active. The display depends upon the Q-RPT
or utility sensor that is active.

Measurement Mode:♦Abs ♦Gage ♦Neg Gage

If an Axxx Q-RPT or a utility sensor is active, all thee measurement modes are supported:
absolute, gauge and negative gauge. Only gauge is available if absolute and negative gauge
modes are OFF (see Section 7.2.5).
If a Gxxx Q-RPT is active, only gauge measurement mode is supported. When <Mode> isselected, <Gauge RPT, gauge mode only> is displayed.

4.5.16<Head>

 PURPOSE
To edit the pressure fluid head correction added or subtracted to the pressure measured by
the PPC4 reference pressure transducer in order to predict the pressure at a height otherthan the PPC4 reference level (see Section 3.2.16).
 OPERATION
To access the HEAD function, use <Head>. The display is:
Edit Head Height:+ 25 cm N2

1.

Entry field for head height.

2.

Test gas currently specified for the head correction.

Edit the head height to the desired value.  to return to the Main Run Screen with the newhead correction active.  to return with no changes.

Note
The reference height of the
PPC4 pressure measurement is
the middle of the PPC4 TEST
port. The head height should beentered as a positive value if thedevice or system under test is
higher than the PPC4 andnegative if it is lower.

4.5.17

PPC4 PRESSURE CONTROLLER/CALIBRATOR<Purge> PURPOSE
To execute the PPC4 test system PURGE function using the optional Self Purging Liquid Trap
(SPLT). PURGE is used to collect and exhaust liquid contaminants from the device orsystem under test before they reach the PPC4 (see Section 3.2.17).
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PPC4™ OPERATION AND MAINTENANCE MANUAL OPERATIONNote
For the Purge function to execute, the function must have been enabledusing <Spec>, <Internal>, <Purge> (see Section 4.5.7.4) and an optional
Self Purging Liquid Trap (SPLT) must be installed in the test line (seeSection 2.3.7.1).
To purge the UUT and/or system under test using the PURGE function, proceed as follows:
Connect the system or device under test (UUT) to the PPC4 TEST(+) port:
Make sure the optional SPLT is properly installed between the UUT and the PPC4,TEST(+) port including the electrical connection for the PPC4 DRIVER connector to the
SPLT valve. Always clean as much liquid and contamination as possible out of the UUT
before connecting it.
Set the purge pressure: Use the PPC4 direct pressure control keys (see Section 3.2.1)
or automated pressure control (see Section 4.2.1) to set the purge pressure.
The purge pressure should be roughly the UUT full scale or 1 MPa (150 psi), whicheveris lower. Avoid activating the purge function at pressure > 1 MPa (150 psi).
Select <Purge> from the Main Menu:

Note at any time during execution of the purge routine causes the purge
function to abort and returns to the Main Run Screen.
Confirm your intention to run the PURGE routine with .
If the current pressure is over 700 kPa (100 psi) gauge, the display is:1.

Current measured pressure.

2.

Active Q-RPT position designation.

3.

Indication that PPC4 is reducing pressure to thepurge pressure of < 700 kPa (100 psi).

876.88 kPa a
IH
Descending to purge

PPC4 controls pressure down to less than 700 kPa (100 psi), stops control and displays<Preparing to purge> for five seconds. After the five second delay, PPC4 opens the
SPLT exhaust valve and displays <PURGING>.
Once the pressure reaches less than 20 kPa (3 psi) gauge or 110 kPa (16 psi) absolute,
PPC4 opens its internal vent valve and returns to the Main Run Screen in its normal
vented condition.
Repeat steps and until no liquids or other contaminants are expelled when the SPLT
exhaust valve opens.

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5. ADVANCED USER INTERFACE

5.

Advanced User Interface

5.1

Main Run Screen

The PPC4-ui Main Run Screen is the home display for the advanced user interface. It is displayed on
power-up and is the screen from which all other functions and menus are accessed. It is the top level ofthe menu structure.
The Main Run Screen is where the operator works with PPC4 to set and read pressures.
It provides complete information on the system’s current configuration and operating status.
Figure 11 shows the PPC4 Main Run Screen display fields and selectable fields. Table 15 lists the contents
and purpose of these fields as well as references to manual sections for more detailed information andexplanation.

Note
PPC4 has a screen saver function that is enabled after a period of inactivity.
Pressing any key or rotating the knob restores the display. The screen saver
display can be selected, the time delay can be changed or screen saving can besuppressed (see Section 5.7.7.1).

Figure 11. Main Run Screen Display and Selectable Fields (see Table 15)

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Table 15. Main Run Screen Fields and Buttons
FIELD




DESCRIPTIONPURPOSECONTENTSSECTION[Tools] button

Access PPC4 Tools functions

none

AutoZero

Shortcut to run AutoZero screen

5.7.5.1(absolute measurement mode only)

Uncertainty

Shortcut to the Uncertainty settings
screenMeasured pressure uncertainty
value

7.2.7.3



Head

Shortcut to the Head settings
screenCurrent pressure head value,
fluid

5.7.6.3

[AutoRange] buttonEnter the AutoRange screen

Target PressureEnter to set target pressure.

Numeric value and sign

Pressure Information

Display pressure information
depending on PPC4 function. Labelabove defines contents.

Label: Target (control target
pressure) or

Display pressure measured by
active Q-RPT

Numerical pressure value andsign

5.7.6.4<Green>:

Ready

3.2.3

<Yellow>:

Near Ready<Red>:

Not ReadyMeasured Pressure



5.7.1
5.5.1

Deviation (deviation fromtarget value)

Shortcut to Resolution Screen
Ready/Not Ready indicator

Indicate pressure Ready/Not Ready
Control Mode

Control Status Indicator

Indicate current control mode andcontrol status

Control mode: Static or
Dynamic

Shortcut to control settings screen

Indicator solid: not controlling

5.7.8.2

Indicator animated: controlling
Measurement Mode

Identifies measurement mode ofdisplayed pressure
Shortcut to measurement mode
screenUnit of Measure

Identifies pressure unit of measurein which measured pressure andpressure information values are
displayed

Absolute

5.7.6.2

Gauge
Negative Gauge
Pressure unit of measureabbreviation

5.7.6.1

Shortcut to unit of measure screenPressure Rate of Change

Display rate of change of pressure
in current units per second

Numerical value and sign incurrent pressure units/s

none

AutoRange Range Indicator

Display AutoRange limits

Lower and upper limits of
AutoRanged range with bar graphof measured pressure

3.2.6

Lower and upper limits of Q-RPT
span with bar graph of measured
pressure

3.2.6

5.7.1

Active Q-RPT Span Indicator

Display active Q-RPT limitsLeak Test

Shortcut to leak test screen

5.7.3.2



Purge

Shortcut to purge screen

5.7.3.1



AutoTest

Shortcut to Advanced AutoTest

5.7.2



[Settings] buttonEnter the PPC4 Settings menu

none



* Noted fields have pressure values expressed in current pressure units.

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5. ADVANCED USER INTERFACE

5.2

Other Screens

All lower level screens (screens other than the Main Run Screen) have similar formats. The screen in
Figure 12 shows one possible lower level screen shown by selecting [Settings], <Pressure>. Numbereddisplays and selectable fields are described in Table 16.

Figure 12. Advanced Interface Lower Level Screen Example (see Table 16)
Table 16. Lower Level Screen Displays and Selectable Fields
FIELD

DESCRIPTIONCONTENTS

Selectable fields



Tabs
<Pressure>,<Control> and <More >>>

Current AutoRange Range

Value of range in currently active unit of measureCurrent Pressure, Ready Status and Control
Indicator

Ready Indicator, Control Indicator, Measurement Mode, Pressure andUnit of Measure

Screen Heading

Heading of currently active screen

Active RPT and Location

IH
IL
X1H

Internal Hi
Internal Lo
External RPM4 Hi

X1LExternal RPM4 Lo






Display list of fields available for selection and editing in currently active
tab <Pressure><Preferences>,

Available tabs for selection. Each tab contains selectable or editable
fields.

<More >>> tabShow more tabs available for selection

Current values

Some editable fields display current values on the selection screen forconvenience so the user can see them without having to select the fieldand change screens to do so.

[Esc] button

Returns to Main Run Screen

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PPC4™ OPERATION AND MAINTENANCE MANUAL

5.3

Keypad Layout and Protocol

The PPC4 has a keypad and navigation knob for local operator access to on screen menus and for data
entry in addition to direct pressure control keys.

 Numeric keypad (black characters on white keys)
 Navigation controls – navigation keys and knob for selecting
and entering menus and fields in the graphic display (whitecharacters on blue keys)

 Direct pressure control keys to manually control pressure,enter a target pressure or toggle the vent sequence. (whitecharacters on grey and black keys)
 Vent indicator LED

Figure 13. Keypad layout

5.4

Conventions for the Advanced Interface
5.4.1

Navigation Controls and Keypad

Menu navigation and selection with the graphical display is described in the text as follows:•[xxx] indicates buttons, (i.e. [Tools])•<xxx> indicates tabs (i.e. <Control>)•xxx indicates other fields (i.e. Unit)

Buttons, tabs and fields used in sequence are shown on one line, separated by commas, forexample:[Settings], <Pressure>, Unit
Front panel keys are shown as individual keys, (i.e. )NoteFor dedicated front panel keys, such as , , , and , any time akey is shown in the manual, it should be interpreted to mean “press thiskey”. For example:  to return to the Main Run Screen means “Pressthe  button to return to the Main Run Screen”.
The numeric keypad is used for data entry and editing. Pressing  changes the numericalsign when editing.
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5. ADVANCED USER INTERFACE

5.4.2

Navigating Advanced Interface Menus
Note
Throughout the Advanced Interface section of the manual the following
terms are used, when presented with initial capitals and in italics, thesewords have the following meanings:
SelectMove the cursor or screen focus between fields by rotating
the knob. Can also use the cursor control keys (  and )to move the cursor.

Enter

Push the knob on a Selected field. Can also use .

The advanced interface is a “point and click” style interface, much like navigating on acomputer screen. Simply Select a button, tab or field on the screen and then Enter to move
forward in the menu selection. To edit a field either Select the field and Enter or start editing
the value with the keypad. Enter to accept an entry.
 typically returns to the Main Run Screen from other screens or causes execution tocease or suspend if an automated process or sequence is in operation.  from the Main Run
Screen allows momentary viewing of the PPC4 model information screen.
Examples of typical screens and descriptions of how to navigate in them are shown in thefollowing examples.
Example 1: Selecting an Individual Field from a Tabbed
Form.
[Settings], <Pressure>, Pressure UnitEnter [Settings] to open the Settings tab screen. From
here scroll between tabs <Pressure>, <Preferences>,<Control> and <More >>>.
Entering the <Pressure> tab from the Settings screen
enters the Pressure settings screen, shown. From here
select and Enter a field in the <Pressure> tab.
[Esc] or  to return to the Main Run Screen.

Example 2: Continuing from Example 1 to select a unit of“psi” from a List.
[Settings], <Pressure>, Pressure Unit, <Favorites> psiEnter the Pressure Unit field from the <Pressure> tab todisplay the Pressure Unit screen. Scroll between tabs
<Favorites>, <All units> or <User units>.
Enter <Favorites> to allow selecting one of the five mostrecently used units and entering a new unit, for example“psi”. The currently active selection is shown in gray.
[Back] to go back one menu level to the Settings screen.
[Esc] or  to return to the Main Run Screen without
making a new selection.

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Example 3: Selecting from a Scrolling List.
[Settings], <Pressure>, Pressure Unit, <All units>,
MPa
Continuing from Example 1, Enter Pressure Unit andthen <All Units> presents a list of units with a scroll bar at
the right. Rotating the knob clockwise or pressing 
scrolls down in the list.
Rotating the knob
counterclockwise or pressing  scrolls up. Click theknob or  to select.
From inside a scrolling list press  to exit back to the tab
screen. From the tab screen, either select another tab,enter the scrolling list again or use [Back] or [Esc].
[Back] to go back one menu level to the Settings screen.
[Esc] or  to exit the menu and make no change.
Example 4: Editing a Numeric Value.
[Settings], <Pressure>, Pressure Unit, <User units>,
User Defined #1
To create or edit a User defined unit, Enter <User units>
in the Unit screen. Enter Units/Pa and input a value
using the numeric key pad.
[OK] to accept.
[Back] to go back one menu level to the Settings screen.
[Esc] or  to return to the Main Run Screen and makeno change.

Note•

Whenever the [OK] button is present it isnecessary to press [OK] to accept any
changes or they will be discarded.

•

When highlighted, numeric fields havewhite text on black backgrounds. Whenediting, numeric fields change to black
text on white background.

Example 5: Selecting from a Drop Down List.
[Settings], <Remote>, COM1
A field, such as Baud Rate, Parity, Data Bit or Stop Bit
in the COM1 screen is in drop down menu format. Enter
one of these fields to display a list of the selections
available.

Note
When the [OK] button is present it isnecessary to press [OK] to accept any
changes or they will be discarded.

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Continuing Example 5, entering Parity displays a list.
Select and Enter to accept the new parity value.
[Settings], <Remote>, COM1, Parity[OK] to accept the changes.
[Esc] or  to make no change.

Note
When the [OK] button is present it isnecessary to press [OK] to accept any
changes or they will be discarded.
Example 6, editing a text field.
[Settings], <Pressure>, Pressure Unit, <User Units>,
User Defined #1, Unit Name[<<] and [>>] position the cursor over a character. Enteror  to open the drop down selection of letters, numbers
and symbols. Scroll through the list to select. Enter or 
the desired character and advance to the next letter.
[Delete] to remove the character.
When the [OK] button is present it is necessary to press[OK] to accept any changes or they will be discarded.

5.5

Pressure Control
5.5.1

Set Pressure Automatically PURPOSE
To use the automated pressure control functions of PPC4 to set and maintain target pressure
values (see Section 3.2.12).
 OPERATIONTo set a pressure,  from the Main Run Screen or click on the Target Pressure field of theMain Run Screen. The Set Pressure screen will display with the Target Pressure field
highlighted. Using the numeric keypad, enter the target pressure value as desired (seeSection 5.5.1.2 for information on zero pressure commands).
Press  or click the knob to accept the target value and start the pressure control sequence,
returning to the Main Run Screen. The Main Run Screen during active pressure control
depends on whether or not the pressure control is Ready or Not Ready (see Section 3.2.3).
When the pressure is approaching the target (Not Ready) the window displays the Measured
Pressure and, below, the Target Pressure (labeled Target). The Ready indicator is either
Red while pressure is slewing to the target (Not Ready) or Yellow (Near Ready) when thefine pressure control is approaching the target.
In dynamic control mode (see Section 3.2.2.1), when the pressure has reached the target
pressure within the defined Ready criteria, the Target pressure is shown in place of themeasured pressure and, below, the difference in actual pressure from target is shown(labeled Deviation). In static control mode (see Section 3.2.2.2), the measured pressure isshown continuously along with Target and Rate.
Observe the Ready/Not Ready indicator (see Section 3.2.3) for indication of when thecontrolled pressure has reached the target and stabilized. PPC4 continues controlling

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following static or dynamic control operation protocol (see Section 3.2.2) until automatedpressure control is interrupted.

5.5.1.1

Interrupting Automated Pressure Control

Automated pressure control is interrupted by:•

: Suspends control and remains in Main Run Screen. Does not ventpressure. PPC4 passively measures the pressure applied to its TEST(+)
port.

•

Selecting any field or shortcut key with the knob or the cursor control
keys ,  and : Suspends control and goes to the selected function.
Does not vent pressure. PPC4 passively measures the pressure.

•

Selecting and entering the target pressure screen with the knob orpressing : Suspends control and goes to Set Pressure screen. Does notvent pressure. PPC4 passively measures the pressure applied to its TEST(+)
port.

To resume automated pressure control, press select and enter the target
pressure screen or press  then ENTER a target pressure value.

5.5.1.2

Automated Pressure Commands for Zero
Pressure

Zero in
gauge
mode:

A command for automated pressure control to a target value of zero when ingauge or negative gauge measurement mode is interpreted in the samemanner
as
if

had
been
pressed(see Section 3.2.14). A Ready condition occurs when the vent sequence hascompleted, including running AutoZ if applicable (see Section 3.2.22).

Zero inabsolute
mode:

In response to a command for automatic pressure control to a target value ofzero when in absolute measurement mode, PPC4 opens its down control valves
fully to the EXHAUST port allowing the vacuum source connected to the
EXHAUST port to pull down the pressure as far as possible (see Figure 31). The
down valves stay open until another pressure command is given or control isaborted. How low the pressure in the PPC4 and the system connected to the PPC4TEST(+) will go is a function of the quality of the vacuum pump used, thecharacteristics of the volume and tubing connected to the TEST(+) port and
PPC4’s internal restrictions.
A Ready condition occurs when the pressure control stability limit is reached (seeSection 3.2.3). Measured pressure will continue to display even when Ready.

5.5.2

Manual Pressure Control

 PURPOSE
The manual pressure control keys provide direct manual control to increase, decrease, andjog the PPC4 pressure.
 OPERATION
 or  when automatic control is not active causes pressure to increase or decrease at
the fast slew rate.
 or  when automatic control is active produces no response.
 or  when automatic control is not active causes pressure to increase or decrease at
the slow slew rate.
 or  during dynamic control causes the pressure to jog or step by a fixed amount.
During active dynamic pressure control, they cause the target pressure to be changed by the
fixed amount. One press causes one step. The approximate value of the step is set

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automatically depending on the current active PPC4 range. The value can be adjusted bynavigating to [Settings], <Control>, Jog Step (see Section 5.7.8.3).

5.5.3

Vent

 PURPOSE
 activates a sequence to bring the test pressure to atmosphere (see Section 3.2.14).
 OPERATION causes PPC4 to control pressure to near atmospheric pressure and then open thesystem vent valve (see Figure 31 andFigure 32). On-going execution of the vent function isindicated by lighting a RED LED to the left of the  key. Completion of the vent process isindicated by the Ready/Not Ready indicator light becoming GREEN with the vent RED LED
still lighted. The vent valve remains open until  is pressed again, another direct pressure
control key is pressed, or an automated pressure control command is given.

5.6

Advanced Interface Menus
5.6.1

Shortcuts

All PPC4 Advanced Interface functions are available through the Main Run Screen buttons( [Tools], [Settings] and [AutoRange] ) and the direct pressure control keys such as and. Shortcuts give quick access to the most common functions. The shortcut fields are
identified in Figure 11 and Table 17. Enter a shortcut to navigate directly to the menu
associated with that function.
For example, clicking on the Unit of Measure (see item 11 in Figure 11 and Table 15) is thesame as navigating the menu sequence: [Settings], <Pressure>, Pressure Unit. Table 17
lists each shortcut and the associated menu for each.

5.6.2

Menu Structure

Table xx shows the top level menu structure for the Advanced Interface. Most day to day
operations are accessible through the shortcuts (see Section 5.6.1). All functions areavailable through menus that are grouped by functionality.

Note[Settings] contains numeric entries that determine how the PPC4 will
operate, what calculations will be made and environment and setup
commands. Typically Settings functions are entered only to set up the
PPC4 prior to performing some action or starting a series of tests.
[Tools] is for action-oriented functions.
[Tools] functions include
AutoTest, Leak Test and other sequences that involve pressure control
and measurement. Items in the Tools menu involve some kind of action.
[AutoRange] creates, edits and deletes AutoRanges, optimizing
measurement and control of the PPC4 over specified ranges. (See
Section 3.2.8)

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Table 17. Advanced Interface Menu Structure
MENU SELECTION

SHORTCUTSEE SECTION(SEE FIGURE )Target Pressure or 

5.5.1

[AutoRange]

5.7.1[Tools], <AutoTest>, Exercise

5.7.2.1
5.7.2.2[Tools], <AutoTest>, Quick Test
[Tools], <Auto Test>, Advanced Test

AutoTest

5.7.2.3[Tools], <Pressure>, Purge

Purge

5.7.3.1

Leak Test

5.7.3.2

AutoZero

5.7.5.1[Tools], <Pressure>, Leak Test

5.7.4

[Tools], <Drivers>[Tools], <System>, Run AutoZ[Tools], <System>, Control Configuration

5.7.5.2[Tools], <System>, Resets

5.7.5.3[Settings], <Pressure>, Pressure Unit
[Settings], <Pressure>, Measurement Mode
[Settings], <Pressure>, Head
[Settings], <Pressure>, Resolution

Unit of Measure

5.7.6.1

Measurement Mode

5.7.6.2

Head

5.7.6.3

Measured Pressure

5.7.6.4[Settings], <Preferences>,Screen saver

5.7.7.1[Settings], <Preferences>, Sounds

5.7.7.2[Settings], <Preferences>, Time

5.7.7.3[Settings], <Preferences>, Language

5.7.7.4
5.7.7.5[Settings], <Preferences>, Security[Settings], <Control>

Control Mode

5.7.8

[Settings], <Remote>

5.7.9[Settings], <Calibration> , Hi RPT, <Calibration>

7.2, 7.4
7.2, 7.4[Settings], <Calibration>, Hi RPT, <AutoZ>[Settings], <Calibration>, Hi RPT, <Uncertainty1>

Uncertainty

7.2.7.3(Hi RPT active)[Settings], <Calibration>, Hi RPT, <Uncertainty2>

7.2.7.3[Settings], <Calibration>, Lo RPT, <Calibration>

7.2, 7.4[Settings], <Calibration>, Lo RPT, <AutoZ>

7.2, 7.4[Settings], <Calibration>, Lo RPT, <Uncertainty1>

Uncertainty

7.2.7.3(Lo RPT active)[Settings], <Calibration>, Lo RPT, <Uncertainty2>

5.7

7.2.7.3[Settings], <Calibration>, Barometer

7.3[Settings], <Internal>

5.7.12

Menu operation
5.7.1

AutoRange PURPOSE
To automatically set up PPC4 to optimize its measurement and control characteristics andfeatures to cover a specific pressure range (see Section 3.2.8).

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5. ADVANCED USER INTERFACE

 OPERATION
To use the AutoRange function, use [AutoRange]from the Main Run Screen. The AutoRange
screen shows the current settings on the left handside and a series of buttons on the right for
AutoRange actions. [OK] to accept and activate
the AutoRange, [Back] or [Esc] to return to theMain Run Screen.
To choose an existing saved AutoRange, selectfrom the contents of the Range: drop down menu
and enter an existing range.

Note
The Default ranges of each of the available Q-RPTs are included in thislist, representing the full scale ranges of the Q-RPTs. Default ranges
cannot be deleted (see Section 3.2.6).
[AutoRanger]: creates a new AutoRange. The AutoRanger screen has the following fields
to select:
Unit: The unit of measure associated with the AutoRange (seeSection 3.2.10).

Note
Altitude units of measure (m, ft) are not supported for AutoRange.
Mode: The measurement mode associated with the AutoRange (seeSection Section 3.2.11). The choice of measurement modes
offered reflects all the Q-RPT types available (Axxx, Gxxx,
BGxxx) in the PPC4 system, not just the active Q-RPT.
Full Scale: Edit the full scale pressure value in the unit of measure specified in
the Unit field. [OK] to accept. If the full scale pressure entered cannot
be covered by any of the Q-RPTs available, an error window isdisplayed (“No suitable RPTs found”). If the full scale pressure can becovered by an available Q-RPT, the entry is accepted.
Use UUT Tolerance: If this field is “Yes” the UUT Tolerance is used to determine the
PPC4 resolution and hold limit settings for the resulting
AutoRange. If this field is “No” the resolution and hold limit
settings for the resulting AutoRange are determined based on
the AutoRange full scale and the active selected Q-RPT.
UUT Tolerance: If enabled, the tolerance of the device under test, in % of
AutoRanged span, associated with the resulting AutoRange.
[OK] from the AutoRanger screen continues to the AutoRange
Confirmation screen, where the specified Full Scale, Unit, Modeand UUT Tolerance are listed in addition to the selected RPT.
Selecting the RPT drop down list shows all available RPTs thatcan cover the specified AutoRange. If an RPT other than the one
selected is desired, it may be chosen from this list.

Note
If an external Q-RPT that should be available is not being selected by
AutoRange then choose [AutoRange], [RPT Search] from the Main Run
Screen and determine whether external Q-RPTs have been properly
connected and initialized (see Section 2.3.6).
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PPC4™ OPERATION AND MAINTENANCE MANUAL[OK] from the AutoRange Confirmation screen creates the range, [Back] returns to the AutoRanger
screen and [Esc] or  exits to the Main Run Screen and does not create the AutoRange.
[Save Range]: Click to save an AutoRange to the Range drop down list.
[Delete Range]: Click to delete the currently selected AutoRange from the Range drop down list.
[RPT Search]: To search for, initialize and display internal and external Q-RPTs available to the
PPC4 system. Selecting an available Q-RPT changes Range to the default range of that Q-RPT.

Note•[Esc] from the RPT Search screen the PPC4 will return to the Main
Run Screen and no AutoRange changes that were made after the last
[Save] will be stored.

•[OK] creates the newly defined AutoRange and to uses it in operation.
If a range is selected from the list, [OK] changes the active range tothe selected Range. [Esc] returns to the Main Run Screen withoutchanging the currently active AutoRange.

•

To verify or confirm the range from the Main Run Screen, use[AutoRange] from the Main Run Screen and view the Range field toview the active range (see Section 3.2.8) or view the AutoRange andactive Q-RPT spans and indicators from the AutoRanger bar on themain run screen (see Figure 14).

The AutoRange Bar in the middle of the PPC4 Main Run Screen displays the range and agraphical indicator of the measured pressure within the range for both the active AutoRanged
Range and the active Q-RPT (see Figure 14, showing a 200 kPa AutoRanged Span on a
700 kPa Q-RPT).

 AutoRange Bar Q-RPT Span AutoRanged Span Indicator Q-RPT Span Indicator AutoRanged Span

Figure 14. AutoRange Bar Caution•

Before operating PPC4 with external Q-RPTs, check carefully that the
Q-RPT TEST(+) port is connected to the PPC4 TEST(+) port. If theexternal Q-RPT is NOT connected to the PPC4 TEST(+) port, it will notmeasure the pressure generated by PPC4 and PPC4 may reach apressure higher than the target pressure before its watchdog function
recognizes that the external RPT is not connected.

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•

5.7.2

RPM4 with Q-RPT full scale spans below 14 MPa have SDS self
defense system to isolate and protect the Q-RPTs. If an external
RPM4 SDS pressure rating is less than the PPC4 maximum pressurethen a warning will be displayed on the PPC4 front panel when the
RPM4 is detected. In addition, AutoRanged ranges greater than the
SDS rating are not allowed (see Sections 3.2.5, 6.5.4, 3.2.8). In order tocreate AutoRanged ranges or generate pressures above the SDS
pressure rating the RPM4 must be disconnected or the RPM4 SDS
must be upgraded to a higher pressure rating. Upgrades may be doneat the DH Instruments service center (see Table 36).

AutoTest PURPOSE
To execute a programmed sequence of automated pressure control target values and/or to
AutoRange the PPC4 based on the full scale and tolerance of the device under test (seeSection 3.2.15). [Tools], <AutoTest> accesses the main AutoTest menu.

5.7.2.1

Exercise

Exercise cycles pressure with the PPC4 between a minimum value (atmosphereor 0) and a maximum target. The PPC4 can start the descending portion of thecycle immediately or can control at the maximum target for a specified period oftime before decreasing pressure.
 OPERATION
To run an Exercise sequence, [Tools], <AutoTest>, Exercise from the Main Run
Screen.
In the Exercise screen enter the following:
Cycles: The number complete (up and down) cycles for the
exercise sequence (0 – 50).
Max Target: The maximum pressure of the target sequence. The
PPC4 will control up to this pressure and either releaseor control at target, based on user selection. Value must
be within the Upper and Lower limits of the current
AutoRange span (see Section 3.2.8).
Min Target: The minimum pressure of the target sequence, selectedfrom a drop down list. The available selections dependon measurement mode and active Q-RPT type.
Gauge mode: Min=0
Absolute mode: Min=0 or ATM
Negative Gauge mode, Axxx Q-RPT: Min=0
Negative Gauge mode, BGxxx Q-RPT : Min=0 or -Max
Control at Target: From the drop down list, Yes to maintain pressure
control at Max Target during the Delay time before
decreasing pressure. No uses a fast ramp and aborts
near the target without controlling at the target.

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Delay at Target: Enter the time at Max Target and Min Target before
continuing with the next step in the sequence. If Control
at Target is set to Yes then pressure control will bemaintained during this delay. If Control at Target is set
to No then pressure control will abort and the PPC4 willbe idle during this delay.
[Back] returns to the AutoTest screen. [Esc] or  exits the Exercise menu andreturns to the Main Run Screen. [OK] accepts the settings and proceeds to the
Exercise Run Screen.
The Exercise Run Screen displays the Cycle count (cycle in progress / total
number of cycles) and the Time at Ready which counts down from the Delay atTarget value to 0.
In the Exercise Run Screen, [Start] to begin the Exercise sequence. At any time,[Stop] to abort the sequence and reset the counter. [Back] aborts the sequence
and returns to the Exercise entry screen. [Esc] or  aborts the sequence andreturns to the Main Run Screen.
When the exercise sequence is complete the PPC4 sounds three two second
beeps and returns to the main menu.

5.7.2.2

Quick Test

 OPERATION
To run a Quick Test sequence, [Tools], <AutoTest>, Quick Test from the Main
Run Screen.
From the Quick Test screen enter the following:
Max: The maximum test pressure for the sequence. The
value must be within the current AutoRange limits (seeSection 3.2.8). To change the current AutoRange see
Section 5.7.1.

Note
The maximum pressure of the currently available AutoRange isshown in the upper left hand corner of the Quick Test window.
See Section 5.7.1.
Min: The minimum test pressure for the sequence.
Step: The step size in % of test sequence span (Max-Min).
Test will run with pressure steps of (Max-Min)*Step%
with the uneven increment at the Max pressure if
applicable.
Direction: Direction of test execution.
Up – starts at Min and ends at Max
Down – starts at Max and ends at Min
Up/Down – sequence runs from Min to Max and backto Min
Down/Up – sequence runs from Max to Min and backto MaxPage 100

5. ADVANCED USER INTERFACE[OK] to accept test settings and continue. [Back] to return to <AutoTest>. [Esc]or  to exit to the Main Run Screen.
In the next screen enter the following:Continue Mode: From the drop down list choose User or Timer. If User ischosen the test sequence will proceed to the next target
value only after  or the knob is pressed. If the Timeris selected then the next test sequence will proceed after
the timer value has elapsed.
Timer: The time, in seconds, the pressure will hold at each step
if the Timer mode is selected. Timer can be between 1
and 9999 seconds.
[OK] to accept settings and continue to the Quick Test run screen, [Back] toreturn to the Quick Test setup screen or [Esc] or  to exit to the Main Run
Screen.
In the Quick Test Run Screen, [Start] begins the Quick Test sequence. Oncethe sequence begins, the Point counter displays current sequence increment /total increments. If the control mode is dynamic (see Section 3.2.2.1), once a
Ready condition has been achieved (see Section 3.2.3)  and  can be used
to adjust the pressure set by the PPC4 until the UUT reaches the cardinal valueof the pressure increment using the Jog function (see Section 3.2.20). In User
Continue Mode, once the UUT has reached the cardinal value of the pressure
increment then use [Next Point]. In Timer Continue Mode, once the pressure is
Ready, the sequence will proceed automatically after the delay has elapsed.

Note
While the Quick Test is running, the upper half of the display isexactly the same as the Main Run Screen, displaying the Ready
indicator, control indicator, measured pressure, target pressure
and pressure rate of change. See Section 5.1.
At any time during the sequence, [Previous Point] causes the PPC4 to go backand retake the previous test point. [Next Point] stops the current point andmoves to the next test point in the sequence. On the last test point [Stop] isshown instead of [Next Point]. Completing the last point or [Stop] moves to the
Quick Test summary screen.
[Back] aborts the sequence and returns to the previous screen. [Esc] or 
aborts the sequence and returns to the Main Run Screen.
Once the test is complete the results are shown on the Quick Test summary
screen. The pressure values from the PPC4 are shown with the respective
sequence numbers. If there are more than eight points in the test then a scroll
bar is shown.
[Back] returns to the Quick Test Run Screen to start the same test sequenceagain. [Esc] or  returns to the Main Run Screen.

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5.7.2.3

Advanced Test

The Advanced Test provides the opportunity to create, save and run up to 20 test
sequences with greater flexibility than with Quick Test.
 OPERATION
To run, edit or delete an Advanced
Test sequence, [Tools], <AutoTest>,
Advanced Test from the Main Run
Screen.
At the top of the Advanced Test
screen is the Test field, with a drop
down list of previously saved
Advanced Test sequences. To run atest from this list, select the test.

Note
The summary information of the test is then shown in the Test:
field as well as in the information fields on the left side of thescreen. Checking this information helps to ensure that thecorrect sequence is being run and that it will not exceed the
maximum pressure of the UUT.
From the Advanced Test main screen, selections include:[New] Create a new Advanced Test.
[Edit] Edit and existing Advanced Test.
[Delete] Deletes the active Advanced Test
[OK] Runs the active Advanced Test
[Back] Returns

to

the

[Tools],<AutoTest>

PPC4 PRESSURE CONTROLLER/CALIBRATOR

tab[Esc] or  exits to the Main Run Screen

5.7.2.3.1

New Test[Tools], <AutoTest>, Advanced Test, [New] initiates creation of an Advanced
Test. The first step in creating an Advanced Test is to create an AutoRange forthe test span (See Section 5.7.1).
In the AutoRanger screen there are fields to select or enter values.
Unit: The unit of measure associated with the AutoRange.
Mode: The measurement mode associated with the
AutoRange. The choice of measurement modes offeredreflects all the Q-RPT types available (Axxx, Gxxx,
BGxxx) in the PPC4 system, not just the active Q-RPT.
Full Scale: Enter the full scale pressure value in the unit of measurespecified in the Unit field and [OK] to accept. If the fullscale pressure entered cannot be covered by any of the
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5. ADVANCED USER INTERFACE

Q-RPTs available, an error window is displayed (“Nosuitable RPTs found”). If the full scale pressure can becovered by an available Q-RPT, the entry is accepted.
Use UUT Tolerance: If this field is “Yes” the UUT Tolerance is used todetermine the PPC4 resolution and hold limit settings forthe resulting AutoRange. If this field is “No” theresolution and hold limit settings for the resulting
AutoRange are determined based on the AutoRange fullscale and the active selected Q-RPT.
UUT Tolerance: If enabled, the tolerance of the device under test, in % of
AutoRanged span, associated with the resulting
AutoRange. Used to determine control limits and to
determine pass/fail for test restuls.
[OK] from the AutoRanger screen enters the AutoRange Confirmation screen,where the specified Full Scale, Unit, Mode and UUT Tolerance are listed inaddition to the selected RPT. Selecting the RPT drop down list shows all
available RPTs that can cover the specified AutoRange. If an RPT other than the
one selected is desired, it may be chosen from this list. Back to return to the
AutoRanger screen. [Esc] or  exits to the Main Run Screen.

Note
If an external Q-RPT that should be available is not being
selected by AutoRange, use [RPT] to search for Q-RPTs anddetermine whether external Q-RPTs have been properly
connected and initialized (see Section 2.3.6).
[OK] from the AutoRange Confirmation screen creates the range and continues,[Back] returns to the previous screen. [Esc] or  exits to the Main Run
Screen.
Continuing enters the Advanced Test
editing screen where test values arelisted on the left and test sequence
editing buttons are given on the right.

Note
The pressure unit for the test points is shown to the right of thetest value list and may be different from the current, active unitof measure (see Section 3.2.10).
To edit the numerical value of a test point:
Select the entry in the test value list and Enter or  to access the list.
Select the test point to edit.
Enter or  again to choose the point and exit to the Test Point field.
The counter shows which test point is active (test point number / total
number of points).
Edit the value of the test point with the numeric keypad.
Enter or  to accept the edited value.
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PPC4™ OPERATION AND MAINTENANCE MANUAL[Auto Fill]: This function creates a test sequence of uniform steps. From thenext screen enter the following:
Max: The maximum test pressure for the sequence. The
value must be within the newly created AutoRange
limits. [Back], [Back] to edit this AutoRange.
Min: The minimum test pressure for the sequence.
Step: The step size in % of test sequence span (Max-Min).
Test will run with pressure steps of (MaxMin)*Step% with the uneven increment at the Max
pressure if applicable.
Direction: Direction of test execution.
Up – starts at Min and ends at Max
Down – starts at Max and ends at Min
Up/Down – sequence runs from Min to Max andback to Min
Down/Up – sequence runs from Max to Min andback to Max[OK] to accept and activate the Auto Fill settings and return to the
Advance Test edit screen. [Back] to return to the previous screen
without making changes. [Esc] or  to exit and return to the Main Run
Screen without saving the test.
[Add]: Adds a Test Point below the currently active (highlighted) point in the test
list. The new point is created with the same numerical value as the point above
it. The value of the new test point can be edited immediately using the numeric
keypad.
To add another point below the first, [Add] again.
To add another point at a different location, Select the entry in the test value list,
Enter and Select the point that will be above the new point. Enter then [Add] as
before.
[Add ATM]: Adds an atmospheric (vent) point below the currently active pointin the test list. The new point value is shown as “ATM”.
[Delete]: Deletes the currently active point in the test list. After deleting thepoint below the deleted point becomes the active point.
[Delete All]:

Deletes all of the points in the test list.

[OK] to continue to the next screen. [Back] to return to the AutoRanger. [Esc]or  to exit and return to the Main Run Screen.
Continuing from the Advanced Test setup screen to the next screen. Enter thefollowing:Continue Mode: From the drop down list choose User or Timer. If User ischosen the test sequence will proceed to the next target
value only after  or the knob is pressed. If the Timeris selected then the next test sequence will proceed after
the timer value has elapsed.
Timer: The time, in seconds, the pressure will hold at each step
if the Timer mode is selected. Timer can be between 1
and 9999 seconds.
Control Mode: Choose Static or Dynamic control mode (see Section
3.2.2).
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5. ADVANCED USER INTERFACE[OK] to accept the new Advanced Test and return to the Advanced Test main
screen, [Back] to return to the previous screen or [Esc] or  to exit to the Main
Run Screen.

5.7.2.3.2

Edit Test[Tools], <AutoTest>, Advanced Test, [Edit] opens the currently selected
Advanced Test sequence for editing.

Note•

Editing an Advanced Test sequence follows the same
steps as creation of a New Test (See Section 5.7.2.3.1),
starting with the AutoRange.

•

Editing any field in the AutoRanger screen will cause thetest points to be regenerated automatically as default
values. Any changes to the AutoTest sequence need tobe made from the Advanced Test editing screen.

After all changes have been made, from the Advanced Test “Continue mode”
screen, [OK] to accept and save the edited Advanced Test. [Back] to return tothe previous screen. [Esc] or  to exit and return to the Main Run Screen
without making a change to the selected Advanced Test.

5.7.2.3.3

Delete Test

[Tools], <AutoTest>, Advanced Test, [Delete] deletes the currently active
Advanced Test.

 Caution
Be sure to select the test that is to be deleted before using[Delete]. Verify that the test sequence listed in Test: represents
the test that is to be deleted. Once a test is deleted it cannot be
retrieved and must be recreated.

5.7.2.3.4

Run Advanced Test

[Tools], <AutoTest>, Advanced Test, [OK] runs the selected AutoTest.

Note
Before running an advanced test, first select from the [Test]
drop down menu the Advanced Test that is to be executed. If
the desired test is not present then a new test will need to becreated (See Section 5.7.2.3.1).
In the Advanced Test Run Screen, [Start] begins the Advanced Test sequence.
Once the sequence begins, the Point counter displays current sequenceincrement / total increments. If the control mode is dynamic (see Section
3.2.2.1), once a Ready condition has been achieved (see Section 3.2.3)  and can be used to adjust the pressure set by the PPC4 until the UUT reaches
the cardinal value of the pressure increment using the Jog function (see Section
3.2.20). In User Continue Mode, once the UUT has reached the cardinal valueof the pressure increment then use [Next Point]. In Timer Continue Mode, oncethe pressure is Ready, the control will sequence will proceed automatically after
the delay has elapsed.

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Note
While the Advanced Test is running, the upper half of thedisplay is exactly the same as the Main Run Screen, displaying
the Ready indicator, control indicator, measured pressure,target pressure and pressure rate of change. See Section 5.1.
At any time during the sequence, [Previous Point] causes the PPC4 to go backand retake the previous test point. [Next Point] stops the current point andmoves to the next test point in the sequence. On the last test point [Stop] isshown instead of [Next Point] Completing the last point or [Stop] moves to the
Advanced Test summary screen.
[Back] aborts the sequence and returns to the previous screen. [Esc] or 
aborts the sequence and returns to the Main Run Screen.
Once the test is complete the results are shown on the Advanced Test summary
screen. The pressure values from the PPC4 are shown with the respective
sequence numbers. If there are more than eight points in the test then a scroll
bar is shown.

Note
Select and Enter the highlighted number in the list to scroll.
If UUT Tolerance is used (specified in the AutoRanger screen, see Section
5.7.2.3.1) then the summary screen will also include “pass” , “fail” or “ATM” foreach point in the sequence. The criteria for pass/fail assumes that the UUT is
adjusted to the cardinal values of each test point and calculates an error basedon the difference between the test point and the PPC4 reading.
Pass:

The difference between the PPC4 pressure and the UUT is less thanor equal to the UUT Tolerance, expressed as a percent of
AutoRange span.

Fail:

The difference between the PPC4 pressure and the UUT is greaterthan the UUT Tolerance.

N/A:

Targets of 0 and Vent do not have pressure adjustment for UUT
cardinal point. Pass/Fail determination is not applicable.

[Back] returns to the Advanced Test Run Screen to start the same test sequenceagain. [Esc] or  returns to the Main Run Screen.

5.7.3

Pressure

The [Tools], <Pressure> tab contains the utility pressure functions Purge and Leak Test.
The [Tools], <Pressure> screen displays the Purge enable status and the results of the last
successful Leak test. If the Purge function is enabled (see Section 5.7.12.3) then the display
shows <Purge: On>. If the Purge function is disabled then the display shows <Purge: Off>.
The Leak Test results show the results of the last successful Leak Test in rate (Units/s) andpressure change in the Units active at the time of the test.

5.7.3.1

Purge

 PURPOSE
To execute the PPC4 test system Purge function using the optional Self Purging
Liquid Trap (SPLT). Purge is used to collect and exhaust liquid contaminantsfrom the device or system under test before they reach the PPC4 (see Section
3.2.17).

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 OPERATIONNote
For the Purge function to execute, the function must have beenenabled using [Settings], <Internal>, Purge, On (see Section
5.7.12.3) and an optional Self Purging Liquid Trap (SPLT) must
be installed in the test line (see Section 2.3.7.1). When thepurge function is enabled the Main Run Screen will show Purge:
On for the Purge shortcut field.
To purge the UUT and/or system under test using the PURGE function, proceed
as follows:
Connect the system or device under test (UUT) to the PPC4 TEST(+)
port:
Make sure the optional SPLT is properly installed between the UUT and the
PPC4, TEST(+) port including the electrical connection for the PPC4DRIVER connector to the SPLT valve.
Set the purge pressure: Use the PPC4 direct pressure control keys (seeSection 3.2.1) or automated pressure control (See Section 5.5.1) to the set
purge pressure. The purge pressure should be roughly the UUT full scale or
1 MPa (150 psi), whichever is lower. Avoid activating the purge function atpressure > 1 MPa (150 psi).
Purge, [Start] or [Tools], <Pressure>, Purge, On from the Main Run
Screen:Note or [Stop] at any time during execution of the purge routine
causes the purge function to abort and returns to the Main
Run Screen.
PPC4 controls pressure down to less than 700 kPa (100 psi), stops control anddisplays <Preparing to purge> for five seconds. After the five second delay,
PPC4 opens the SPLT exhaust valve and displays <Purging…>.
Once the pressure reaches less than 20 kPa (3 psi) gauge or 110 kPa (16 psi)
absolute, PPC4 opens its internal vent valve and returns to the Main Run Screen
in its normal vented condition.
The PPC4 will beep three times to signal the completion of the Purge routine.
Repeat steps
anduntil no liquids or other contaminants are expelledwhen the SPLT exhaust valve opens.

5.7.3.2

Leak Test

 PURPOSE
To run an automated leak check routine that determines the leak rate of the system
connected to the PPC4 TEST(+) port (see Section 3.2.18).
 OPERATION
To run a leak check, first set the pressure to the desired leak check pressureusing the direct pressure control keys (see Section 3.2.1) or automated pressure
control (See Section 5.5.1)
To access the Leak Test function, use [Tools], <Pressure>, Leak Test from theMain Run Screen. The shortcut for Leak Test is Leak Test on the Main Run Screen.
Edit the leak test time, in seconds (minimum 2, maximum 999).  or Enter toaccept the value. [Start] to begin the test.
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PPC4™ OPERATION AND MAINTENANCE MANUAL[Stop] aborts the running leak test. [Start] once more restarts the leak check timer.
At any time during leak test [Esc] or  aborts and returns to the Main Run Screen.
While the leak test is in process the Average Rate and the total change inpressure (dP) are displayed using the currently active unit of measure, withvalues updated throughout the test. When the leak check timer countdown has
finished, the result is shown in the displayed values for Average Rate and dP.
[Start] to run another leak test. [Back] to return to [Tools], <Presure>. [Esc] or to exit to the Main Run Screen.
[Tools], <Pressure> displays the results of the most recently completed leakcheck as well as the Purge enable status. The Leak Test results show theresults of the last successful Leak Test in rate (Units/s) , pressure change in the
Units and the Q-RPT active at the time of the test. If NO leak check data isstored (i.e., if the PPC4 has never run a leak test or a reset has cleared previous
leak test results), <Pressure> displays <Leak Test: None>.

5.7.4

Drivers PURPOSE
To control the output signals of PPC4’s 8 channel, 12 V external drivers (see Section 3.2.23).

Note
See Section 9.1 for driver specifications and pin-outs.
 OPERATION[Tools], <Drivers> opens the driver control screen. Select the driver to change. Enter or 
to change state (On/Off).
When a driver is On, voltage is applied.

When a driver is Off, voltage is not applied.

 Caution
The PPC4 Purge function makes use of the valve driver option. Valve
driver number 8 is used to actuate the SPLT exhaust valve. The SPLT
exhaust valve is actuated when performing the Purge function and in the
background every time the PPC4 Vent function is used. When making useof valve drivers, note that when the Purge function is enabled, valve driver
number 8 will be actuated independently of user initiated valve drivercommands (see Section 3.2.17).
[Esc] or  exit to the Main Run Screen.

5.7.5

SystemUse [Tools], <System> to access Run AutoZ, Control Configuration and Resets.

5.7.5.1

Run AutoZ

 PURPOSE
Run AutoZ with an absolute mode Q-RPT in order to compensate for possible
changes in Q-RPT zero between full recalibrations (see Section 3.2.22).

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 OPERATION

Note•

Run AutoZ applies only to Axxx Q-RPTs in absolutemeasurement mode. In gauge and negative gaugemeasurement modes, AutoZ is run automaticallywhenever the PPC4 is in the Vent condition (see Section
3.2.14).

•In order to Run AutoZ, AutoZ must be On. To turn AutoZ
On or Off use [Settings], <More >>>, <Calibration>, xx RPT,
<AutoZ>, Absolute AutoZ (where xx RPT could be Hi RPT
or Lo RPT). See Section 7.2.7.2.

To open the Run AutoZ menu from the Main RunScreen use [Tools], <System>,
Run AutoZ. The shortcut to Run AutoZ is AutoZ on the Main Run Screen. If thecurrent measurement mode is gauge or negative gauge, a message indicatingthat AutoZ cannot be run manually in gauge mode is displayed. If AutoZ is OFF
for the active Q-RPT then an error message will indicate that AutoZ is notavailable.

Note
Allow the PPC4 to stabilize at atmospheric pressure andambient temperature for 10 to 15 minutes before running AutoZ.
The Run AutoZ screen shows a numeric entry field for Pstd,0, the reference pressure.
This is the pressure reading of the reference device used for comparison. Note thatthe reference pressure must be entered in the same unit of measure as the PPC4
pressure. The current PPC4 pressure is shown for reference on the second line.

Note•

While the value of Reference (Pstd,0) is entered in thecurrent pressure unit of measure, the value of Poffset isalways in Pascal (Pa).

•If running AutoZ results in a value of Poffset that is greaterthan ± 0.005 % FS of the span of the Q-RPT that is being
AutoZeroed, the Q-RPT and/or the reference used as thesource of Pstd,0 may be out of tolerance or the AutoZ
process may have been faulty. Before activating a new Poffset
greater than ± 0.005 % FS of the active Q-RPT, check to be
sure that both the Q-RPT and the reference were in goodworking order, properly vented to stable atmosphericpressure, at the same height, and reading in the samepressure units when AutoZ was run.

•

When running AutoZ, if a Head correction is currently
active (see Section 3.2.16), it is momentarily disabled to
avoid “zeroing out” the head value.

5.7.5.2

Control Configuration

 PURPOSE
This function is considered part of PPC4 maintenance and is therefore coveredin the maintenance section of this manual. See Section 7.5.
 OPERATIONThis function is considered part of PPC4 maintenance and is therefore coveredin the maintenance section of this manual. See Section 7.5.2.
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5.7.5.3

Reset PURPOSE
To reset various PPC4 settings to default or factory values. Use [Tools],<System>, Resets to access the Reset functions (see Section 3.2.25).

 Caution
PPC4 reset functions will change current settings to factory
defaults. These may include settings vital to PPC4 operation
and affecting the calibration of the quartz reference pressuretransducers (Q-RPTs). Reset functions should only be used byqualified personnel with knowledge of reset consequences. Resetfunctions should not be used experimentally.

5.7.5.3.1

Settings

 PURPOSE
Sets most general operating parameters back to default values. Does not affectcalibration coefficients, remote interfaces or AutoRange ranges (see Section 3.2.25.1).
 OPERATION
From the Main Run Screen use [Tools], <System>, Reset, Settings.
[Yes] to activate changes (perform the reset). The PPC4 will cycle power tocomplete and return to the Main Run Screen. [No] to make no changes andreturn to the Reset screen.

5.7.5.3.2

Units

 PURPOSE
Resets Unit selections to factory defaults (see Section 3.2.25.2).
 OPERATION
From the Main Run Screen use [Tools], <System>, Reset, Units.
[Yes] to activate changes (perform the reset. The PPC4 will cycle power tocomplete and return to the Main Run Screen. [No] to make no changes andreturn to the Reset screen.

5.7.5.3.3

AutoTest PURPOSE
Resets Exercise, Quick Test and Advanced Test to default characteristics (seeSection 3.2.25.3).
 OPERATION
From the Main Run Screen use [Tools], <System>, Reset, AutoTest.
[Yes] to activate changes (perform the reset. The PPC4 will cycle power tocomplete and return to the Main Run Screen. [No] to make no changes andreturn to the Reset screen.

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5.7.5.3.4

Calibration
 Caution

The Reset Calibration function will reset Q-RPT, utility sensor
and barometer calibration coefficients and settings and reset
AutoZ values to zero.
This will change the PPC4 calibrationand could cause it to make out of tolerance measurements.
Clears all user values affecting the calibration of Q-RPTs, utility sensor and theon-board barometer. Does not clear factory coefficients (see Section 3.2.25.4).
 OPERATION
From the Main Run Screen use [Tools], <System>, Reset, Calibration[Yes] to activate changes (perform the reset). The PPC4 will cycle power tocomplete and return to the Main Run Screen. [No] to make no changes andreturn to the Reset screen.

5.7.5.3.5

Reset All
 Caution

The Reset All function clears and deletes large amounts of user
defined information including critical calibration data.
Combines all resets in one global reset command that clears the entire user
section of non-volatile memory returning PPC4 to the “as delivered” condition
except the ID function and the security level password. (See Section 3.2.25.5).
 OPERATION
From the Main Run Screen use [Tools], <System>, Reset, Reset All[Yes] to activate changes (perform the reset). The PPC4 will cycle power tocomplete and return to the Main Run Screen. [No] to make no changes andreturn to the Reset screen.

5.7.6

Pressure

Use [Settings], <Pressure> to access Pressure Unit, Measurement Mode, Head andResolution. The [Settings], <Pressure> tab displays the current values of each of these four
settings. Select and Enter to edit settings.

5.7.6.1

Pressure Unit

 PURPOSE
To select the unit of pressure in which PPC4 displays pressure values.

Note
For information on selecting the measurement mode (absolute,gauge, negative gauge), see Section 5.7.6.2.
 OPERATION[Settings], <Units>, Pressure Unit opens the Pressure Unit screen.
shortcut for Pressure Unit is the Unit field on the Main Run Screen.
Pressure Unit screen has three tabs.
<Favorites> Lists the most recently selected units.
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PPC4™ OPERATION AND MAINTENANCE MANUAL<All Units> Lists all available units.
<User Units> Lists units defined by the user.
[Back] to return to the Main Run Screen, [Esc] or  to exit to the Main Run
Screen.

Note
The pressure measurement unit selected is range specific.
When in a given range, all functions and settings are
represented in the current measurement unit for that range.
However, certain internal and/or metrological functions (e.g.,
Q-RPT calibration coefficients) are always represented in Pa
regardless of the active range unit of measure. In addition,
when the active unit is an altitude unit, the range and upper
limit indications are in kPa if the unit is meters (m) and psi if theunit is feet (ft).

5.7.6.1.1

Favorites

The Favorites tab in the Pressure Unit menu lists up to ten of the most recently
used units for quick and easy selection. Select and Enter the unit selection. Afterthe unit has been chosen the PPC4 returns to the Main Run Screen with the newunit active.

Note
Every time a new unit is selected from the All Units list (seeSection 5.7.6.1.2) the new unit is added to Favorites.
[Reset] to erase the list of Favorites, [Back] to return to <Pressure>, [Esc] or 
exit to the Main Run Screen without making a change.

5.7.6.1.2

All Units

If the desired unit has not been used recently and is not in the Favorites list, then<All Units> can be selected. The All Units tab provides a scrolling list of all
selectable units. These include the five user defined units (see Section
5.7.6.1.3).
First Enter the scrolling list then scroll through and Select the desired unit ofmeasure.  or Enter to select,  to exit the menu.

Note
Units representing a water column (inches/meters/millimeters of
Water) are all represented with a selection of temperatures fromwhich to calculated density. The temperature is part of the unit
definition. Choose from 4 ºC, 20 ºC or 60 ºF. For example, theunit for inches of water at 20 º is inH2O@20C.
[Back] to return to the <Pressure> tab, [Esc] or  exit to the Main Run Screen
without making a change.

5.7.6.1.3

User Units

If a unit of measure is needed that is not among the predefined units then up to
five user defined units may be created. To create a user defined unit first theconversion from the new unit to Pascal (Pa) must be specified. In order to edit auser defined unit, select [Settings], <Pressure>, Pressure Unit, <User Units>.
Then Select which of the five User Defined units to edit.
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To edit the name using the text editing screen, Select and Enter the Unit Name
field. Selecting and Entering a letter allows brings up the character drop down
list. Enter to accept a replacement character,  to exit the drop down list.
Scroll left and right by using [<<] and [>>]. [Delete] to erase the current
character.
[OK] to accept and return to the Unit edit screen, [Back] to reject changes andreturn to the Unit edit screen, [Esc] or  to reject changes and exit to the Main
Run Screen.
Enter the appropriate value for the number of Units/Pa in the second field of theUser Defined unit screen. For example, the unit kiloPascal (kPa) would haveUnits/Pa equal to 0.001.
[OK] to accept and return to the Main Run Screen, [Back] to reject changes andreturn to the <User Units> tab, [Esc] or  exit to the Main Run Screen without
making a change.

5.7.6.2

Measurement Mode

 PURPOSE
To set the measurement mode (absolute, gauge or negative gauge) for theactive range (see Section 3.2.11).
 OPERATION[Settings], <Pressure>, Measurement Mode brings up the Measurement Mode
screen with the available mode selections. The shortcut to Measurement Modeis the measurement mode field from the Main Run Screen (see Figure 11).
Select and Enter to change the selected mode and return to the Main Run
Screen with the new mode active.
If an Axxx Q-RPT or a utility sensor is active, all thee measurement modes aresupported: absolute, gauge and negative gauge. If absolute and negative
gauge modes are OFF then only gauge mode is available. (see Section 7.2.5).
If a Gxxx Q-RPT is active, only gauge measurement mode is available.
[Settings], <Pressure>, Measurement Mode results in a message: <Onlycurrent measurement mode is available>.
[Back] to return to <Settings>. [Esc] or  to return to the Main Run Screen
without making a change.

Note•

Certain PPC4 settings, including AutoZ ON/OFF (see Section
3.2.22) are range AND measurement mode specific. See
Table 4 for a listing of settings and what they are specific to.

•

Absolute and negative gauge modes on an Axxx Q-RPT canbe turned OFF in the calibration function (see Section 7.2.5).
When absolute and negative gauge modes are turned OFF
for an Axxx Q-RPT, only gauge mode can be activated.

5.7.6.3

Head PURPOSE
To cause a pressure fluid head correction to be added or subtracted to thepressure measured by the PPC4 reference pressure transducer in order topredict the pressure at a height other than the PPC4’s reference level (seeSection 3.2.16).

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Note
Use of the Head function to ensure in tolerance measurements ismost important in low absolute pressure ranges. Specifying thehead height within ± 3 in. (7.5 cm) is adequate to ensure that, evenin the worst case, the uncertainty on the head correction will beinsignificant relative to the tolerance on the measurement.
 OPERATION[Settings], <Pressure>, Head opens the Head screen. The shortcut to Head is
Head: on the Main Run Screen (see Figure 11). In this screen edit:
Height: The height of the UUT or measured pressure above thereference level of the PPC4.
The reference height of the
PPC4 pressure measurement is
the middle of the PPC4 TEST
port. The head height should beentered as a positive value if thedevice or system under test is
higher than the PPC4 andnegative if it is lower.

PPC4 PRESSURE CONTROLLER/CALIBRATOR

Unit: The unit of measure of the height measurement (centimeters or
inches)Medium: The fluid medium in the test connection between the TEST(+)
port and the UUT or measured pressure.
After editing values, [OK] to accept changes and return to the Main Run Screen.
[Back] to return to <Pressure>. [Esc] or  exit to the Main Run Screen without
making a change.

Note•

The currently active head values can be seen on the Headshortcut on the Main Run Screen (see Figure 11). The
height, unit and medium are shown. For example: Head:
0 cm, N2 represents no head correction because theheight is equal to 0.

•

The Head function is NOT range specific. The Head ON or
OFF status remains the same as ranges are changed.
Edits made to the head settings are independent of active
range or Q-RPT.

•

When using external Q-RPTs in RPM4, it is recommended
that the RPM4 head height be adjusted to the reference levelof the PPC4 before connecting the RPM4. Then, the normal
PPC4 reference level to UUT head corrections can be madefor all the Q-RPTs, whether internal or external to PPC4.

5.7.6.4

Resolution

 PURPOSE
To set the resolution with which measured pressures and other pressure
indications and settings are displayed.

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 OPERATION[Settings], <Pressure>, Resolution opens the Resolution screen. The shortcut
to Resolution is the measured pressure field from the Main Run Screen (seeFigure 11). In the resolution window choose from the available choices between
1.0% of full scale and 0.0001% of full scale. The currently active resolution value
is shown in gray.
[Back] to return to <Pressure>. [Esc] or  to exit to the Main Run Screen
without making a change.

Note

5.7.7

•

The resolution setting is range specific. A resolution
setting made in one range does NOT affect other ranges.

•

The measured pressure resolution is fixed for altitude units
at 1 m in meters and 1 ft in feet.

•

The maximum resolution setting is limited in AutoRange
ranges that are less than 10% of the Q-RPT default full scale.

•

The maximum resolution setting when using a utility sensor
is 0.001% of utility sensor span.

Preferences

Use [Settings], <Preferences> to access Screen Saver, Sounds, Time, Language andSecurity. The [Settings], <Preferences> tab displays the current values of each of thesesettings. Select and Enter to edit settings.

5.7.7.1

Screen Saver

 PURPOSE
To adjust the PPC4’s Screen Saver settings (see Section 3.2.26.1).
 OPERATION[Settings], <Preferences>, Screen Saver opens the Screen Saver screen. Edit
Time, from 10 minutes to 8 hours. If Time is set to Off then the screen saver
function will be disabled and the screen will remain on as long as the PPC4
power is on. Editing Style chooses the display when the screen saver isactivated. The choices include “Moving Pressure” which displays the current
measured pressure, moving on the screen, and “DHI” (the DHI logo).
[OK] to accept and return to the Main Run Screen. [Back] to return to<Preferences>. [Esc] or  to return to the Main Run Screen without making achange.

5.7.7.2

Sounds PURPOSE
To adjust or suppress the PPC4 key press sound (see 3.2.26.2).
 OPERATION[Settings], <Preferences>, Sounds opens the Sounds screen. From here choose
None, Low, Medium or High for the valid key press frequency. The currently active
frequency is shown in gray.
Choose None to suppress the key press tone.

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Select and Enter to choose the desired sound and return to the Main Run Screen.
[Back] to return to <Preferences>. [Esc] or  return to the Main Run Screen
without making a change.

5.7.7.3

Time PURPOSE
To view and edit the PPC4 internal time and date settings (see Section 3.2.26.3).
 OPERATIONNote
The PPC4 date and time are set to United States MountainStandard Time in the final test and inspection process at thefactory. If desired, use the Time and Date functions to set yourlocal time and date.
The PPC4 has an internal real time clock that is used for date
and time stamping calibrations and internal logs.
[Settings], <Preferences>, Time accesses the PPC4 date and time settings.
Select and edit these fields to set the time as desired. The year is inyear/month/day format (yyyymmdd). Time may be displayed in either a 12 hour
(AM/PM) or 24 hour format, set by editing Time Style. If Time Style is 24 hourthen AM/PM is blank.

5.7.7.4

Language PURPOSE
To specify the language for PPC4 Advanced Interface display, headings, menus
and screens (see 3.2.26.4).
 OPERATION[Settings], <Preferences>, Language opens the Language screen. Select thepreferred language for on screen display and Enter. The currently active
language is shown in gray.
Select a language and Enter or  to change languages and return to the Main
Run Screen. [Back] to make no change and return to <Preferences>. [Esc] or to make no change and exit to the Main Run Screen.

Note•

The language selection affects to headings, buttons, tabs,
field names and on-screen messages. Numeric displays,
including pressure units and DHI trademarked terms, suchas AutoRange, are always in English.

•

Remote commands and their responses are always in
English, regardless of language setting.

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5. ADVANCED USER INTERFACE

5.7.7.5

Security PURPOSE
To set user protection levels to restrict access to certain functions and to edit the
password required for changing user levels (see Section 3.2.26.5).
 OPERATION[Settings], <Preferences>, Security accesses the PPC4 Security screen. PPC4 isdelivered with no active password and access to the Security screen is open. The
security level is set to Low. Security levels can be changed freely until a password
has been created.
To change the Security level, access the security screen, [Settings],<Preferences>, Security. If there is a password in place, the Password screen
will be displayed. Enter the password at the prompt “Enter Password:”. If nopassword has been entered the Security screen will be displayed immediately,
bypassing the Password screen.

Note
At the bottom left of the Password entry screen is a code (SN:sss-nnnn). The first part (sss) is the PPC4 serial number. The
second part (nnnn) is a numer that is changed each time thesecondary password is used (see 3.2.26.5).
Select and Enter a Security from the choices, Off, Low or High (see Table 11 for
function access affected by the security level).
Entering a choice makes the change and returns to the Main Run Screen.
[Back] returns to <Preferences> without making a change. [Esc] or  exit to
the Main Run Screen without making a change.

5.7.7.6

Edit Security Password[Edit Password] from Security opens the password editing screen. Passwords
can be up to six numbers in length and cannot start with a zero.
If <0> is entered, the password is made inactive and the user will not be required
to enter a password to access the user level menu. This condition, with asecurity level of Low, is the factory default.

 Caution
Once a password has been entered, the user level cannot bechanged without reentering the password or the secondary
password.

Note
The factory secondary password is available in case the user’s
password has been misplaced or forgotten. It can be obtainedby contacting a DHI Authorized Service Center (see Table 36).
The factory secondary password is different for all PPC4’s andchanges each time it is used.
[OK] to accept the change and return to Security. [Back], [Esc] or  exit to
Security without making a change.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

5.7.8

Control
5.7.8.1

Pressure Limits PURPOSE
To set the upper and lower limit pressure value for a pressure range andmeasurement mode (see Section 3.2.21).
 OPERATION[Settings], <Control>, Pressure Limits opens the screen to edit or reset theUpper and Lower Limits.
To modify the upper limit, edit the value, noting the pressure units associatedwith this value. [OK] to accept changes and return to the Main Run Screen.
[Back] to return to <Control> and make no changes. [Esc] or  to exit to theMain Run Screen and make no changes.

Note•

If the current measurement mode is absolute or gauge,
there is an upper limit only. The maximum upper limit is
105 % of AutoRange range or 102 % of default Q-RPT
range, whichever is smaller.

•

RPM4 with Q-RPT full scale spans below 14 MPa have
SDS self defense system to isolate and protect the QRPTs. If an external RPM4 SDS pressure rating is lessthan the PPC4 maximum pressure then a warning will be
displayed on the PPC4 front panel when the RPM4 isdetected.
In addition, AutoRanged ranges greater thanthe SDS rating are not allowed (see Sections 3.2.5, 6.5.4,
3.2.8). In order to create AutoRanged ranges or generatepressures above the SDS pressure rating the RPM4 must
be disconnected or the RPM4 SDS must be upgraded to ahigher pressure rating. Upgrades may be done at the DH
Instruments service center (see Table 36).

If the current measurement mode is negative gauge or the Q-RPT is a BA100K,
there is also a lower limit that may be edited. For an Axxx Q-RPT operating in
negative gauge mode, the lower limit is –ATM by default. The value may be edited
but must be negative. To restore the value of –ATM use [Default Limits].

Note•

The lower limit must be a negative value.

•

The default lower limit for a BGxxx Q-RPT in negative
gauge mode is the negative equivalent of the upper limit•

The default lower limit for a BA100K Q-RPT in negative
gauge mode is 66 kPa (9.6 psi).

[Default Limits] resets the Upper and Lower Limits to the default values for theactive Q-RPT and range.
[OK] to accept the changes and return to the Main Run Screen. [Back] to returnto <Control> without making changes. [Esc] or  to exit to the Main Run
Screen without making changes.

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5. ADVANCED USER INTERFACE Caution
Upper limit values are specific to each range and measurement
mode. Be careful not to assume that the upper limit set in one
measurement
mode
will
apply
to
the
other.
For example, if you set 150 kPa as the upper limit in gaugemode, the upper limit will not be 150 kPa in negative gauge
mode of the same range.

Note
Upper limits are always specified and displayed in the current
pressure unit except for altitude units. When in altitude units,
upper limits are expressed in kPa if the altitude unit is meters(m) and psi if the altitude unit is feet (ft).

5.7.8.1.1

Over Pressure Function

In addition to the UL function, PPC4 has an over pressure function (see Section
3.2.21.1).
To recover from an overpressure condition, correct the overpressure conditionand cycle PPC4 power. Be sure to correct the condition that caused theoverpressure before cycling power.

5.7.8.2

Pressure Control

 PURPOSE
To set the automated pressure control mode for the active range, customize
control parameters, activate default control parameters (see Section 3.2.2).
 OPERATION[Settings], <Control>, Pressure Control opens the screen to select the control
mode and to set the control limits.
Select Static or Dynamic to change to that control mode and exit to the Main
Run Screen. The shortcut to Pressure Control is the control mode indicator on
the Main Run Screen (see Figure 11).
Select [Limits] from the Pressure Control screen to adjust or view the Control
Parameters.

NoteControl mode setting is range specific. A change in control
mode made while in one PPC3 range does NOT affect thecontrol mode setting in other ranges.

5.7.8.2.1

Custom Control Parameters (Limits)

 PURPOSE
To view active pressure control parameters and/or set custom control
parameters (see 3.2.2).
 OPERATION
To view active control parameters and/or set custom control parameters, use[Settings], <Control>, Control Limits from the Main Run Screen. Alternatively[Limits] from the [Settings], <Control>, Pressure Control screen or from thecontrol mode shortcut open this screen as well.
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Three fields are available to edit: Hold Limit, Stability Limit (see Section 3.2.13)
and Jog Step (see Section 3.2.20).
Edit the values of the desired parameters, noting the units of measure. [OK] toaccept and return to the Main Run Screen. [Back] to return to <Control> with nochanges. [Esc] or  to exit to the Main Run Screen with no changes.
To restore the default values of the three parameters use [Default Limits].

Note
Custom control parameters are range specific. Changes madein one range are stored for that range and are recalled whenthat range is returned to. Changes made in one range do notaffect any other range.

5.7.8.3

Jog Step PURPOSE
Adjust the nominal change in pressure caused by using the jog direct pressure
control keys ( and ) (see Section 3.2.20).
 OPERATION[Settings], <Control>, Jog Step accesses the Jog Control Limits screen, with the
Jog Step field active. Enter a new value in the currently active pressure units.
[OK] to accept the change and return to the Main Run Screen. [Back] to returnto <Control> without making changes. [Esc] or  to exit to the Main Run
Screen without making changes.

5.7.9

Remote PURPOSE
To configure the PPC4 COM1, COM2, IEEE-488 (GPIB), or LAN communication ports. To
test COM1 and COM2 communications. To select remote programming communications
format (see Section 3.2.24).
 OPERATION[Settings], <More >>>, <Remote> opens the Remote settings screen.
The remote setting screen varies, depending on the communications hardware installed. The
following choices are always available:
COM1: To view and edit COM1 settings (see Section 5.7.9.1).
COM2: To view and edit COM2 settings (see Section 5.7.9.1).
Command Format: To select remote programming command format (see Section
5.7.9.2)
If no optional interface hardware is installed, the following is also displayed.
USB: Indicates front USB port only, not selectable
If the optional IEEE-488 hardware is installed, the following two options are displayed.
IEEE-488: To view and edit IEEE-488 settings (see Section 5.7.9.3)
USB: Indicates front USB port only, not selectable
If the optional Ethernet interface is installed, the following two options are displayed.
USB: Indicates both front and back USB ports, not selectable
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5. ADVANCED USER INTERFACE

Ethernet: To view and edit LAN settings (see Section 5.7.9.4).

5.7.9.1

COM1 and COM2

The COMx ports can be set for specific communications settings. The settings
are baud rate, parity, data bits and stop bits. The available options are:Baud Rate: 1 200, 2 400, 4 800, 9 600, 19 200
Parity: None, Odd or Even
Data Bit: 7 or 8
Stop Bit: 1 or 2
The default is <2400, E, 7,1> for both COM1 and COM2.

Note
The PPC4 looks for an ASCII(13) (carriage return) to terminate areceived command but responds with both and ASCII(13)(carriage return) and an ASCII(10) (line feed). There are no
options.
See also Sections 6.3.1.1,6.3.1.2 and 6.3.1.3.

5.7.9.2

Command Format[Settings], <More >>>, <Remote>, Command Format opens the Command
Format screen. The highlighted format is the currently active format.
[Settings], <More >>>, <Remote>, Command Format, Classic selects theClassic format for commands (see Section 6.4.1)[Settings], <More >>>, <Remote>, Command Format, Enhanced selects the
Enhanced format (see Section 6.4.2).
Selecting a format resets the IEEE-488 interface and puts it into an idle state.
See also Section 6.4.

5.7.9.3

IEEE-488

The IEEE-488 port’s primary address can be set from 1 to 31 in this screen. The factory
default value is 10. Secondary addressing is not used or supported. This address
must not conflict with the address of any other device on the same IEEE-488 bus.

Note
The receiving terminating character must be a line feed and EOI.
Carriage returns are ignored if received. The PPC4 sends a line
feed and asserts the EOI line to terminate a reply. Thesesettings are fixed to agree with IEEE Std. 488.2. If the address
is changed, the IEEE interface resets (PON) and becomes idle.

5.7.9.4

Ethernet[Settings], <More >>>, <Ethernet>, Setting allows selection of DHCP (fordynamic selection of IP address by the LAN (Local Area Network) or
Manual for user entered IP address.
[Settings], <More >>>, <Ethernet>, IP displays IP address. If Setting is“DHCP” then IP is selected by LAN and cannot be edited. If Setting is“Manual” then IP address may be entered or edited.

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PPC4™ OPERATION AND MAINTENANCE MANUAL[Settings], <More >>>, <Ethernet>, UDP displays the UDP port. Cannot
be edited.
[Settings], <More >>>, <Ethernet>, MAC address displays the MAC
address unique to each PPC4 and contained in the Ethernet module if the
Ethernet option is selected. Cannot be edited.

5.7.10Calibration

 PURPOSE
To calibrate the PPC4 utility sensor, Hi and/or Lo Q-RPTs and adjust the on-board
barometer. This function is considered part of PPC4 maintenance and is therefore coveredin the maintenance section of this manual (see Sections 7.2, 7.3, 7.4).
 OPERATION
See Sections 7.2, 7.3 and 7.4.

5.7.11

Uncertainty

 PURPOSE
This function is considered part of PPC4 maintenance and is therefore covered in themaintenance section of this manual. See Section 7.2.7.3.
 OPERATIONThis function is considered part of PPC4 maintenance and is therefore covered in themaintenance section of this manual. See Section 7.2.7.3.

5.7.12

Internal

 PURPOSE
To view, set, adjust, and maintain various aspects of PPC4’s internal operation (seeSection 3.2.27).
 OPERATION[Settings], <More >>>, <Internal> opens the Internal settings screen.

5.7.12.1 ID
 PURPOSE
To enter an alphanumeric identification (ID) for the PPC4 (see Section 3.2.27.1).
 OPERATION[Settings], <More >>>, <Internal>, ID opens the ID edit screen.
[OK] to accept and return to the Main Run Screen, [Back] to return to the ID
screen without making changes, [Esc] or  to exit to the Main Run Screen
without making changes.

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5. ADVANCED USER INTERFACE

5.7.12.2 Control Reference PURPOSE
To specify whether the PPC4 should automatically determine whether a vacuum
source or atmospheric pressure is connected to the EXHAUST port and to
manually set the EXHAUST port condition (see Section 3.2.27.2).
 OPERATION[Settings], <More >>>, <Internal>,Control Reference opens the Control
Reference edit screen.
Setting:

Auto or Manual.

Control Reference:

Vacuum or Atmosphere

Note
Control Reference is only editable if Setting is set to Manual.
[OK] to accept and return to the Main Run Screen, [Back] to return to the ID
screen without making changes, [Esc] or  to exit to the Main Run Screen
without making changes.

5.7.12.3 Purge
 PURPOSE
To enable or disable the PPC4 Purge function (see Section 3.2.27.4).
 OPERATION[Settings], <More >>>, <Internal>, Purge opens the Purge screen. The current
state of the Purge function is shown in gray. On to enable the Purge function.
Select Off to disable.
[Back] to return to <Internal>, [Esc] to return to the Main Run Screen.

5.7.12.4 Event log
 PURPOSE
To view and/or clear the PPC4 event log (see Section 3.2.27.5).
 OPERATION[Settings], <More >>>, <Internal>, Event Log opens the Event log screen if there
are any entries in the log. If the word “None” is showing beside Event Log thenthere are no events (Pmax or Memory faults) in the log. If there are any log
entries then the date and time of the last entry are shown.
In the Event Log screen the log entries may be scrolled through. When a given
date and time are selected the specific entry is shown above the selection box. If
the entry is a Pmax event then the specific RPT is indicated as well as the
maximum recorded pressure in units of Pa.
[Clear Log] deletes and resets the entire log. [Back] returns to the <Internal>
screen and [Esc] or  exits to the Main Run Screen.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

5.7.12.5 TEST (-) Vent
 PURPOSE
To cause a PPC4 or external RPM4’s Gxxx or BGxxx Q-RPT TEST (-) Vent valve tostay open or closed rather than open and close automatically (see Section 3.2.27.6).

NoteThis menu selection is available only when the active Q-RPT is
a Gxxx (gauge) or BGxxx (bi-directional gauge) Q-RPT.
 OPERATION[Settings], <More >>>, <Internal>, TEST (-) Vent accesses the TEST (-) Vent
screen. Selections are Operation and Status.
Operation:

Auto or Manual

Status:Open or Closed

Automatic Operation is the default. Manual Operation allows the selection of always
Open or always Closed. Status entry is only available if Manual operation is
selected.
[Settings], <More >>>, <Internal> to view the settings of the TEST (-) Vent
Valve[OK] to accept and return to the Main Run Screen, [Back] to return to <Internal>
without making changes, [Esc] or  to exit to the Main Run Screen without
making changes.

Note
The TEST (-) VENT function setting always applies to the active QRPT module, whether the module is internal to PPC4 or in an
external RPM4 (see the RPM4 Operation and Maintenance
Manual).

 Caution
If the PPC4 detects a condition in which it determines there could
be a risk of overpressure to the RPT by opening the TEST (-) Vent
valve when a Manual Open is requested, a message indicating a
DP overpressure risk is displayed. If this message is displayed,
return to normal operation, vent the PPC4 and try again.

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6. REMOTE OPERATION

6.

Remote Operation

6.1

Overview

Most of the PPC4 front panel functions can also be executed by commands from a remote computer.
The host computer can communicate to the PPC4 using the PPC4 RS232 (COM1),, IEEE-488 or Ethernet
ports. Remote communications via USB are through the PPC4 API only. See PPC4 API documentation.

Note
The front and optional rear panel USB ports are not directly supported by the remotecommand set. The PPC4 USB interface is supported by the PPC4 Cockpit (see Section
6.2) as well as the PPC4 API (see PPC4 API documentation for details).
Before writing test code which makes use of PPC4 remote commands, familiarize yourself with its
operating principles by reading Section 3 of this manual. Also refer to Sections 6.3.1.3 and Section
6.3.2.1 for testing RS232 and IEEE-488 commands.

6.2

PPC4 Cockpit
6.2.1

Overview

The PPC4 Cockpit is a PC based application that emulates the PPC4 Advanced User
Interface (see Section 5), connecting via any of the available I/O options. The PPC4 Cockpit
allows a PC,monitor, mouse and keyboard to perform all PPC4 display and data entry
functions. All PPC4 Advanced Interface functions are available in the Cockpit. The Cockpit
can be used with either the Basic Interface or the Advance Interface versions of the PPC4.
Multiple PPC4s can be supported at the same time by opening multiple instances of the
Cockpit.
The PPC4 USB port does not support host software in the same manner as the IEEE-488,
RS232 or Ethernet ports (see Sections 6.3.1, 6.3.2 and 6.3.4). However communications
through the PPC4 USB ports may be accomplished through the PPC4 API. See the API
documentation for specifics.

6.2.2

Installation

The PPC4 Cockpit is included in the Software section of the General Accessories CD
distributed with the PPC4. The installation is also available in the PC based Software sectionof www.dhinstruments.com under “pc based free utilities”. The PPC4 USB driver and the
PPC4 Cockpit application are installed by the installation program.

6.2.2.1

USB Driver Installation

After a typical installation the front (or optional rear) USB port of the PPC4 canbe connected to a PC and used to interface with the PPC4 Cockpit. Some PC
configurations will not support the automatic installation of the driver. In this casethe driver must be setup manually. Begin the manual driver setup by connecting
the PPC4 to the PC using a standard USB cable. The Windows Hardware
Wizard will display. Follow the steps below to complete the driver setup process.

Page 125PPC4™ OPERATION AND MAINTENANCE MANUAL

Select the “Advanced” option to select the driver by location. [Next >] tocontinue.

Figure 15. Windows Hardware Wizard

The driver is located in the \Driver sub directory of the PPC4 Cockpit application.
By Default this directory is C:\Program Files\DH Instruments\PPC4 Cockpit\Driver.
Alternatively the driver can be updated from the General Accessories CD
distributed with the PPC4. The proper directory will include the file “cyusb.inf”.
[Browse] to locate the directory that contains the driver. Locate the appropriate
directory. [Next >] to continue.

Figure 16. Driver Location

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6. REMOTE OPERATION

Figure 17. Browse for Driver Location

A driver warning message will display. The PPC4 USB driver has not been
digitally signed for Windows Compatibility. [Continue Anyway] to proceed.

Figure 18. Driver Warning Message

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PPC4™ OPERATION AND MAINTENANCE MANUALThe necessary files will be copied and the setup complete dialog will display.
The PPC4 USB port can now be used with the PPC4 Cockpit. [Finish] toclose the dialog.

Figure 19. Driver Setup Complete

6.2.3

Running the Cockpit

The PPC4 Cockpit must be launched like any other application. It does not auto launch when
the USB or RS232 ports are connected to the host PC. Use the desktop short-cut or the
Windows Start menu to launch the PPC4 Cockpit. The opening program dialog provides the
choice of interface to use for communication between the PPC4 and the PPC4 Cockpit.
Select the appropriate interface to launch the Cockpit. The program loads the active PPC4
settings then displays the PPC4 Advanced display.

Figure 20. PPC4 Cockpit Main Display

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6. REMOTE OPERATION

Figure 21. PPC4 Cockpit Communication Selection

6.2.3.1

USB Interface

If USB is selected, a secondary dialog displays to facilitate the selection of thespecific PPC4. Only PPC4s actively connected to the host PC via USB are listed.
Choose the specific PPC4. [OK] to continue. The Cockpit will load the PPC4
information and run. There are no specific PPC4 menu options required to use
the PPC4 via USB.

Figure 22. PPC4 Cockpit Communication Selection

6.2.3.2

RS232 Interface

Select [RS232] on the opening Cockpit dialog to communicate to the PPC4 via
RS232. It is necessary to verify the PPC4 front panel RS232 settings prior tocompleting the RS232 setup in the PPC4 Cockpit. The selections on the RS232
Settings dialog represent the RS232 port that connects the host PC to the COM1
port of the PPC4. The RS232 settings must represent the RS232 settings
obtained from the front panel of the PPC4 (see Sections 4.5.2.1 and 5.7.9.1).

Figure 23. PPC4 Cockpit RS232 Settings
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6.2.3.3

Keyboard Shortcuts

Several keyboard shortcuts are provided to emulate the pressure control buttons
on the PPC4 front panel. See Table 18 for a list of all pressure control keyboard
shortcuts. There is also a pressure control panel accessed by pressing the arrowon the bottom right of the PPC4 Cockpit display. The pressure control panel has
the same function as the pressure control keys on the PPC4 front panel (seeSection 3.2.1).

Figure 24. PPC4 Cockpit Pressure Control Buttons

Table 18. PPC4 Cockpit Keyboard Shortcuts
PC KEYBOARD SHORTCUT

PPC4 KEY

OPERATION
Increase pressure at the fast slew rate. See Section 3.2.1.

Decrease pressure using the fast slew rate. See Section 3.2.1.

Increase pressure using the slow slew rate. When a dynamic control
pressure target is active, the function changes to increase the target pressure
by the jog step. See Section 3.2.1.
Decrease pressure using the down slow valve. When a dynamic control
pressure target is active, the function changes to decrease the target pressure
by the jog step. See Section 3.2.1.
Set a new target pressure. See Section 3.2.12.

Toggle the state of the PPC4 vent valve. See Section 3.2.14.

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6. REMOTE OPERATION

6.3

Remote Interfacing

Sending a program message to the PPC4 places it into Remote mode. The remote indicator below thethe display window lights when the PPC4 is in Remote mode. It will also flicker when a program
message is received. The menus usually accessed from the front panel are locked out while in remote.
[ESC] returns the PPC4 to local operation unless the <REMOTE> command, which locks out all keypad
operation, was sent to the unit.

6.3.1

RS232 Interface
6.3.1.1

COM1

The PPC4 COM1 RS232 interface is located on the back of the unit. It is a 9-pin
male DB-9F connector configured as a DCE device. Data is transmitted out of
the unit using pin 2, and is received on pin 3. This allows a normal pin-to-pin
DB-9M to DB-9F RS232 cable to be used to connect to a DTE host.

 Caution
Handshaking is not required or supported. The COM1 receive
buffer is 255 bytes deep. If the buffer overflows from sending
too much data, the data will be lost. Because of this, it isessential to send a single program message at a time and it isessential to wait for the PPC4 to reply to a command before
sending any other command.
Table 19. COM1 Pin Designations and Connections
PPC4 COM1 DB-9F PIN DESIGNATIONSPIN #FUNCTIONDESCRIPTION

2

TxD

3

RxD

This pin transmits serial data from the PPC4 to the host.
This pin accepts serial data from the host computer.

5

Grn

This pin is the common return for the TxD and RxD signals.

IBM PC/XT DB-9F
CONNECTIONS

6.3.1.2

IBM PC/XT DB-9M TO PPC4 DB9F
CONNECTION

DB-25M

DB-9F

DB-9M

2

3

3

DB-9F
3

3

2

2

2

7

5

5

5

COM2

The PPC4 COM2 RS232 interface is located on the back of the unit. Its mostcommon use is to connect to DHI RPM4 reference pressure monitors to PPC4 to
add external measurement devices to the PPC4 system (see Section 2.3.6)
COM2 can be used to allow the host computer to communicate with anotherdevice through the PPC4. This allows the user to use one host COM port tocommunicate with the PPC4 and an additional RS232 device. Refer to the “#”
and “PASSTHRU” remote program commands for details.
COM2 is a 9-pin female DB-9F connector configured as a DTE device. Data istransmitted out of the unit using pin 3, and is received on pin 2. This allows a normal
pin-to-pin DB-9M to DB-9F RS232 cable to be used to connect to a DCE device.
Handshaking is not required or supported.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Table 20. COM2 DB-9F Pin DesignationsPIN #FUNCTION

2

RxD

3

TxD

This pin accepts serial data from the external device.

4

DTR

This pin is Data Terminal Ready (DTR) (held at + 5 V).

5Grn

This pin is the common return for the TxD and RxD signals.

6.3.1.3

DESCRIPTIONThis pin transmits serial data from the PPC4 to a device.

RS232 Command TestingAn easy way to test RS232 communications independent of custom software is
to use the Windows Hyperterminal found in the accessories group under All
Programs (See Figure 25)

Figure 25. Windows selection of Hyperterminal

Hyperterminal must be configured to communicate with the PPC4 using theRS232 COM1 communication settings accessed through the PPC4 front panel(see Section 5.7.9.1 for the Advanced Interface and Section 4.5.2.1 for the Basic
Interface). Refer to the following series of steps to configure Hyperterminal
assuming that the PPC4 is connected to COM4 of a host PC using a baud rate of
2400, 7 data bits, event parity and 1 stop bit.
Figure 26 is displayed whenHyperterminal is run for the firsttime. Enter an easily identifiablenametoreference
thecommunications session. Future
Hyperterminal sessions are initiatedby selecting the named session.

Figure 26. Hyperterminal Initial Display

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6. REMOTE OPERATIONThe next dialog defines the
RS232
port
to
use
for
communication. Select the hostPC’s COM port that will beconnected to the PPC4. Do notconfuse this selection with theCOM1 and COM2 ports on theback of the PPC4.

After the COM port selection, theRS232 settings of the PPC4 must
be defined. The specific PPC4
settings are accessed through the
PPC4
front
panel.
RS232
handshaking is not supported by
the PPC4, therefore None is theappropriate selection for Flow
Control.

The focus will return to the main
Hyperterminal program after the
COM port properties are defined.
At this point, the last steps are todefine command and response
terminators.
Access the [File]menu and select [Properties]

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Within the Properties dialog, press
the ASCII setup button.

Make the selections listed in the
figure below. These selections
enable a carriage return (ASCII
13) and line feed (ASCII10) to be
appended to the end of thecommands to the PPC4 and thecorresponding responses. Press[OK] after the edits are complete.

Figure 27. Hyperterminal ASCII Setup

At this point it is best to save and close the current Hyperterminal session.
Open Hyperterminal a second time, choose [Cancel] on the opening dialog,
then use the [File][Open] menu to select the file just created “RemoteCommand testing.

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6. REMOTE OPERATION

6.3.2

IEEE-488

The PPC4 IEEE-488 interface is located on the back of the unit. The physical and electricalinterface conforms to IEEE Std 488.1-1987 Subset E2 and IEEE Std. 488.2-1992. Do not
attempt to communicate with the IEEE-488 interface while using the COM1, Ethernet or USB
interfaces. The IEEE-488 receive buffer is 250 bytes deep. If the buffer overflows, the PPC4
will hold off release of the NRFD handshake line until it can service and empty the receive buffer.
This keeps the buffer from overflowing. It is recommended that you use the query form for all
remote commands and wait for a reply to each command to ensure proper operation andorder of command execution. Not reading a command response will cause the PPC4 torespond improperly to future remote commands.

6.3.2.1

IEEE-488 Remote Command testing

Verify IEEE-488 communication with the PPC4 by using a communication tool
provided by the PC‘s IEEE-488 interface manufacturer. The following sequencedescribes the steps to setup and communicate with the PPC4 by using a NI
(National Instruments) IEEE-488 adapter. Different versions of the NI adapter
and cards from other manufacturers will have slightly different steps and labeling.
Install the IEEE-488 interface into the host PC and verify that the adapter isproperly setup.
Connect the PPC4 to the host PC by using an IEEE-488 communications cable.
Launch the NI Measurement and Automation Explorer. Locate the option toscan for instruments. The PPC4 should be detected at the addresseddefined in [Settings],<Interface>,IEEE-488.

Select the Communicate with Instrument option to invoke a dialog to enter discretecommands to the PPC4. No other specific PPC4 IEEE-488 setup is required.

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PPC4™ OPERATION AND MAINTENANCE MANUALEnter a PPC4 command into the Send String field and choose [Query] or[Write] based on the command entered and the PPC4 command format.
While communicating in Enhanced mode with IEEE-488, no response isprovided by the PPC4 unless a “?” is included with the command.
Attempting to read a response when a “?” is not included will yield aninterface error. If a “?” is included and a response is not read, futurecommands will not respond properly. For this reason, make sure to use the[Read] button if [Write] was used to send a query form command

6.3.3

USB

The PPC4 can be connected to a PC via USB (Universal Serial Bus) through the port on thefront of the instrument. If the PPC4 is equipped with the optional Ethernet module (see 6.3.4),
the connection can be established via the secondary USB port on the back of the unit. Do notconnect to both USB ports simultaneously. To connect the PPC4 to the PC use a standard
USB device cable (included with the hardware). Connect the USB-B plug into the PPC4 USB
socket and the USB-A plug to an available PC USB jack. It is not recommended to operate a
PPC4 via legacy USB 1.x ports. Expansion cards are available to upgrade older PCs to USB
2.0. It is also not recommended to utilize USB extension cords. USB communication is
supported only through PPC4 Cockpit and the PPC4 API (Application Programming
Interface). Refer to the PPC4 API documentation on how to access the PPC4
programatically. To test USB communications run PPC4 Cockpit or use commerciallyavailable 3rd party tools.

Note
PPC4 API documentation is available at www.dhinstruments.com in thesoftware section as well as on the local PC as part of the PPC Cockpit
installation at c:\DHI\help\ppc4api.chm.

6.3.4

Ethernet (Optional)

The optional PPC4 Ethernet interface (8P8C modular connector socket) is located on therear panel, paired with a secondary USB connector. Connect the PPC4 to a network switch
via a standard CAT5 or CAT6 network (patch) cable. The PPC4 communicates with the PC
via the Ethernet module using UDP/IP (User Datagram Protocol/Internet Protocol) on port
2362 (fixed). The IP address of the PPC4 can be assigned statically (typed in) or dynamicallyvia DHCP (Dynamic Host Configuration Protocol) on your LAN (Local Area Network). It might
be necessary to acquire special permission from your IT department in order to use static IP
addresses on a corporate network. It is possible to directly connect the PPC4 to a PC using a
network (patch) cable, bypassing a network. For direct connect enter static IP addresses onboth the PPC4 LAN setup screen and the PC network adapter (refer to Windows
documentation). To test communications via UDP use commercially available 3rd party tools.

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6.4

Programming Formats

PPC4 supports two program message formats, “Classic” and “Enhanced”. The user must select which
format to use. Selection can be accomplished from the front panel (see Section 5.7.9.2 for Advanced
Interface and Section 4.5.2.3 for Basic Interface) or remotely using the “MSGFMT” program message(see Section 6.5.4).
The main difference between the two formats is that when using the IEEE-488 interface, a “?” must be
included in an enhanced command for there to be a response from the PPC4. In all other cases (classic or
enhanced), every command has a response. In addition, the enhanced message format supports IEEE Std.
488.2 syntax, format and status reporting.
The default is the classic format to allow downward compatibility with existing host software.
In either format, it is recommended that you start out a command sequence with the “*CLS” command,
which clears all of the communication and error queues. The basic commands are similar for both theclassic and enhanced formats, but the usage, syntax, format and status reporting are different.

Note
The PPC4 program message set is downward compatible with the previous PPC3
program message set. In some cases additional arguments are available at theend of PPC4 commands that are not available in PPC3 commands. However thecommand function is not altered.

6.4.1

Classic Program Message Format

Each program message sent is also a query. Only one program message can be sent to the
PPC4 at time. After sending any program message, the PPC4 must reply before anotherprogram message can be sent. The reply will contain data, or a numeric error message if the
program message was invalid. The reply must be received before issuing another program
message to the PPC4. This insures that the PPC4 has completed the program message.
Most remote program messages will return a reply within 500 ms except:“PR”, “PRR”, “SR”, “ATM”, “RATE”: Up to 2.0 seconds to allow a new measurement.
“RPT”, “ARANGE”: Up to 10 seconds
The syntax and format used for each program message in the classic mode is listed next to
the keyword ‘Classic:’ in each program message summary in Section 6.5.4.

6.4.2

Enhanced Program Message Format

The enhanced program message format uses the IEEE Std. 488.2 format, syntax and status
reporting. Errors are reported using the IEEE Std. 488.2 status reporting model. If an error isreported, the error is put into an Error Queue and the “ERR?” query program message canbe used to get a text description of the most recent error. If you are using the IEEE-488 port,
the service request line can be setup to be asserted if this occurs (see Section 6.6.2). In theenhanced format, there are two possible program message types for every program
message. Each of these two types starts with the same basic text referred to as the program
message header. The two types are COMMAND type and QUERY type commands.

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6.4.2.1

Using Command Type Commands
Note

Enhanced format commands DO NOT reply when using theIEEE-488 interface unless a “?” is included in the command.
There will be no response from PPC4 to non-query (no “?”)commands.
Remote software can time-out waiting for a
response from PPC4. However, in RS232 communications,
there is always a response and the response MUST be readprior to issuing another command.
The COMMAND type of program message executes a process and can
additionally send data to the PPC4 in the form of comma delimited arguments.
This data is usually a setting of some sort that is stored in the PPC4. If data is
specified, it must be preceded by at least one white space from the program
message header and be within the range and format described in the program
message description. The keyword “Command:” appears to the left of therequired syntax in each program message description in Section 6.5.4 .
If you are using the IEEE-488 port, the Command type does not generate a reply
unless you place a query operator “?” immediately after the command. You also
may send multiple program messages at once by separating each program
message with a semicolon. The commands are queued and executed in asreceived order after the entire message stream has been received, so care in
determining order of execution is needed.
If you are using the RS232 port COM1, the Command type will always generate
a reply so you must wait for a reply before issuing another program message.
Because of this, you can only send one Command program message at a time
while using the COM1 port.
Examples:•IEEE-488 enhanced mode command series using query operator:“*CLS?”(Clear the error queue. Wait for reply.)“UNIT? KPA” (Generates a reply.
User must wait for reply before
continuing.)“MMODE? A” (Generates a reply.
User must wait for reply before
continuing.)“PS? 100”(Generates a reply.
User must wait for reply before
continuing.)•

IEEE-488 enhanced mode commands without query operator:“*CLS”“UNIT KPA”
“MMODE A”“PS 100”“ERR?”•(Clear the error queue. No reply.)(No reply)(No reply)(No reply)(Wait for reply. User should use “ERR?” query following aseries of non query commands to check for errors that may
have occurred.)IEEE-488 enhanced mode multiple commands without query operator:“*CLS”(Clear the error queue. No reply)“UNIT KPA;MMODE A;PS 100” (Three commands at once. No reply)“ERR?”(Wait for reply. User should use “ERR?”
query following a series of non querycommands to check for errors that may
have occurred)
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COM1 enhanced mode command:“*CLS” or “*CLS?”“UNIT KPA” or “UNIT? KPA”
“MMODE A” or “MMODE? A”“PS 100” or “PS? 100”

6.4.2.2(Clear the error queue. Wait for reply.)(Generates a reply. User must wait for
reply before continuing.)(Generates a reply. User must wait for
reply before continuing.)(Generates a reply. User must wait for
reply before continuing.)

Using Query Type Commands

The QUERY type of program message just requests data from the PPC4.
Placing the query operator “?” immediately after the command creates a query.
Software must wait for a reply with a query. If any type of program message is sent
to the PPC4 after a query before receiving a reply, the program message will bediscarded and an error will be generated. Errors are reporting using the IEEE
Std. 488.2 status reporting model. A Query program message always ends witha question mark. Most queries will return a reply within 200 ms except:“PR?”, “PRR?”, “SR?”, “ATM?”, “RATE?”: Up to 2.0 seconds.
“RPT”, “ARANGE”: Up to 10 seconds
The syntax for using a QUERY program message is listed next to the keyword“Query:” in each program message summary in Section 6.5.4 .

6.5Commands
6.5.1

Programming Messages
Table 21. Program Message List#

Send a command string out of the PPC4 COM2 port.

ABORT

Stop pressure generation.

ARANGE

Read or set a new AutoRange to use.

ATM

Read the current atmospheric pressure (on-board barometer).

AUTOPURGE

Read or set the status of the automatic purge function.

AUTOVAC

Read or set the status of the control reference (EXHAUST port).

AUTOZERO

Read or set the status of the AutoZ automatic zeroing function.

CALAMB

Read or set the on-board barometer calibration

CMDTERP

Gets or sets the command interpretation header.

COM1

Read or set the configuration of the COM1 port.

COM2

Read or set the configuration of the COM2 port.

DATE

Read or set the current date.

DF

Decrease the pressure quickly (fast).

DISPUNC

Enable or disable display of uncertainty and select the display modeDP

Decrease the pressure a given amount.

DRV

Read or set the status of the external valve drivers.

DS

Decrease pressure slowly.

ERR

Read the last error message.

GPIB

Read or set the GPIB interface address.

HEAD

Read or set the fluid head settings.

HS

Read or set the current control hold limit in pressure.

HS%

Read or set the current control hold limit in percent span of the active range.

ID

Read or set the PPC4 alphanumeric asset ID tag.
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Increase the pressure quickly (fast).

IP

Slowly increase the pressure a given amount.

IS

Increase the pressure slowly.

Ln

Gets or sets the command interpreter mode.

LAN

Read or set the optional network interface settings.

LL

Read or set the lower limit for the current range (negative gauge mode only).

LOCAL

Return control to the PPC4 front panel.

MEM

Read the power-up memory test status.

MMODE

Read or change the active measurement mode.

MODE

Read or set the current pressure control mode.

MSGFMT

Read or set the type of program message format to use.

NVENT

Read or set the status of the lo vent valve (Gxxx or BGxxx Q-RPT only).

PASSTHRU

Send a command string out of the PPC4 COM2 port.

PCAL:IH

Read or set the user Hi RPT calibration information.

PCAL:IL

Read or set the user Lo RPT calibration information.

PCALUNC:IH
PCALUNC:IL

Read or set the Q-RPT uncertainty settings used to determine the RPT’s measurement
uncertainty during operation.

PR

Read the next PPC4 pressure.

PRR

Read the next available pressure, rate, on-board barometer reading, control status, andthe QRPT uncertainty.

PS

Set a new target pressure and start automated pressure control.

PSF

Set a new target pressure and use only the fast speed to reach the target.

PSS

Set a new target pressure and use only the slow speed to reach the target.

QPRR

Quickly read the last known pressure, rate, on-board barometer reading, control status
and QRPT uncertainty.

RANGE

Read or set and Q-RPT or utility sensor default range (PPC4 command).

RATE

Read the next available rate of change of pressure.

READYCK

Read or set a flag that is cleared by a Not Ready condition.

REMOTE

Enable remote local lockout operation.

RES

Read or set the pressure display resolution for the current transducer and range.

RESET

Reset the PPC4 to the default user parameters.

RETURNStart a new automated pressure control set using the current target value.

RPT

Read the available Q-RPT data or initiate the RPT search process.

SCRSAV

Read or set the front panel display screen saver activation time & type.

SN

Read the serial number of the PPC4.

SR

Read the next available pressure status (Ready/Not Ready).

SS

Read or set the stability required for a Ready condition.

SS%

Read or set the stability required for a Ready condition (% span/ s).

STAT

Read the pressure control status.

TIME

Read or set the current time of day.

TIMEFMT

Read or set the clock time format.

TP

Read the current target pressure.

UCOEF

Convert a pressure in Pascal to pressure in the current units.

UDU

Read or set the user defined pressure unit.

UL

Read or set the upper limit for the current range.

UNIT

Read or set the pressure unit of measure for the current range.

VAC

Read or set the exhaust reference status flag.

VENT

Read, execute or abort a vent process.

VER

Read the PPC4 software version.

ZOFFSETn

Read or set the AutoZero Poffset for the specified Q-RPT.

ZOFFSET:IH

Read or set the AutoZ offset for Hi RPT.

ZOFFSET:IL

Read or set the AutoZ offset for Lo RPT.

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6.5.2

Error Messages
Table 22. Error #s and DescriptionsREPLY

DESCRIPTIONERR# 0“OK”

ERR# 2“Text argument is too long”

ERR# 3“Arguments cannot be 0”

ERR# 4“External device not detected”

ERR# 5“External device improperly configured”

ERR# 6“Numeric argument missing or out of range”

ERR# 7“Missing or improper command argument(s)”ERR# 8“External device time-out error”

ERR# 9“Unknown command”

ERR# 10“Missing or invalid command suffix”

ERR# 11“Command missing argument”

ERR# 12“System overpressured” or “overpressure may result”

ERR# 13“Text queue overflow”

ERR# 14“User unit not defined”

ERR# 16“Generation failure”

ERR# 18“Command not yet available”

ERR# 19“Not available with absolute units”

ERR# 20“Not available with gauge device”

ERR# 21“User device not defined”

ERR# 22“Pressure is not stable”

ERR# 23“Option not available or installed”

ERR# 24“Unit must be vented”

ERR# 25“Transducer out of calibration”

ERR# 26“COM port failed to initialize”

ERR# 27“Internal device failure”

ERR# 28“Device failure”

ERR# 29“Device not available”

ERR# 30“Must be on range IH”

ERR# 31“Exceeds upper or lower limit”

ERR# 32“Not stable enough”

ERR# 37“Data table is full”

ERR# 38“Selected range is not available”

ERR# 39“Data verify error”

ERR# 45“Argument not allowed”

ERR #46“Argument cannot be negative”

ERR #52“Command obsolete”

ERR# 53“Not Available”

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6.5.3

Program Message Description Overview

Each program message description is separated into the following sections:PurposeA brief description of the programs message’s function.

CommandThis is the Enhanced program message syntax to send data to the PPC4 or to execute a
PPC4 function. The PPC4 must be set to use the enhanced format (see Section 3.5.2.3)
to use the syntax and style shown. It may be sent alone, or followed by at least one whitespace and additional argument(s) to show that arguments can be passed. If there are
multiple arguments, then commas must separate them. If you are using the IEEE-488
port, multiple command type program messages can be sent in one message if you
separate them with a semicolon. There will be no reply from the PPC4 using the IEEE488 port unless the command is immediately followed by the query operator “?”. If you
are using the COM1 port, the PPC1 will reply and you must wait for this reply. If this field
is not listed in the program message description, then the Command type is not supported
when using the Enhanced format.

QueryThis is the Enhanced program message syntax to request data from the PPC4. The
PPC4 must be set to use the enhanced format (see Section 3.5.2.3). The PPC4 will
always reply to a query. You must wait for this reply before issuing another program
message. If this field (Query) is not listed in the program message description, then theQuery type for the program message is not supported when using the Enhanced format.

Classic

This is the Classic program message syntax to send data to the PPC4, to execute a
PPC4 function, or to query for data. The PPC4 must be set to use the classic format (seeSection 3.5.2.3).
The command may be followed by a ‘(=)’ and additional argument characters to show thatargument(s) can be passed. If there are multiple arguments, then commas must separate
them. The PPC4 will always reply to a Classic program message. You must wait for this
reply before issuing another program message. If this field is not listed in the program
message description, then it is not supported when using the classic format.

Arguments

If the program message can be used to set data inside the PPC4, then this section
describes the arguments and their limits.

Default

If the program message can be used to set data inside the PPC4, then this line shows(using the enhanced format) the default setting from the factory.

Remarks

This field has the details and remarks about the command.

ExampleExamples are given for the enhanced and classic methods.
Enhanced: An example of the use of an enhanced format program message to be sent
to the PPC4 is shown. The message sent to the PPC4 appears after the“Cmd sent:” label. If only a Query type exists, the “Query sent:” label isshown instead. Directly under this label, “Query reply” shows a typical
reply to a query type. “Reply:” shows that a query format does not exist.
It may have a short description next to it.
Classic:

An example of the use of a classic program message to be sent to the
PPC4 is shown. The command sent to the PPC4 appears after the “Cmd
sent:” label. The “Reply” label shows a typical reply to the “Sent”
example.
It may have a short description next to it.

ErrorsIf the program message can report an argument error, the types of errors are listed.
If using the classic format or the COM1 port, the error message is replied after receiving
the program message. If using the enhanced format via the IEEE-488 port, the error
condition is handled by the status reporting model which stores the errors in an Error
Queue and can be programmed to assert the IEEE-488 SRQ line to signal an error has
occurred. In either case, the “ERR” or “ERR?” program message can be used toretrieve a text description of the error.

See Also

Indicates related command (“----“) and refers to manual sections giving detail on PPC4
operation corresponding to the program message.

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6.5.4

Program Message Descriptions#
PurposeTo allow the host PC to communicate with a device connected to the PPC4 COM2 port.
The preferred method is to use the “PASSTHRU” program message.

Classic“#xx”

Arguments

xx:

Remarks

The PPC4 COM2 port can be used to communicate to another RS232 device (such as
another PPC4). This allows the user to use one COM port or IEEE-488 port on the hostcomputer to communicate with the PPC4 and another device. A carriage return and aline feed (<CR><LF>) are added to the string.

The string to send out of the COM2 port. It must be less than
40 characters long.

After this program message is issued, the PPC4 will reply back the first string received by
the PPC4 COM2 port that is terminated with a carriage return. Line feeds are discarded.
This will discontinue when the next program message is sent to the PPC4.
There is no other reply from this program message. Prior to using this program message,
you must ensure that the PPC4 COM2 port is correctly set up to communicate with thedevice on COM2. Refer to the “COM2=“ program message.
ExampleSent:“#VER”(classic)

Reply:“DH INSTRUMENTS, INC PPC4 us A1000/A0015 Ver2.00 ”

This example assumes that a second PPC4’s COM1 port is connected to the PPC4
COM2 port. This example gets the version of the second PPC4.
See Also“PASSTHRU”, “COM2”
3.2.24

Note
COM2 is generally used for connecting DHI RPM4s to supply externalmeasurement devices in which case communications are handled
automatically by the PPC4.
ABORT
PurposeStops active pressure generation/control. All control valves are closed. The exhaust andtransducer isolation valves are not affected.

Command“ABORT”

Classic“ABORT”

Remarks

This program message has no effect if the PPC4 is not using automated pressure control.
When using automated pressure control, it aborts the control. This command isrecommended to idle the PPC4 before setting a new target pressure.

ExampleCmd sent:“ABORT”(enhanced)

Reply:“ABORT” (no reply if IEEE-488)

ExampleCmd sent:“ABORT?”(enhanced)

Reply:“ABORT”

ExampleSent:“ABORT”(classic)

Reply:“ABORT”

See Also

3.2.12, 3.2.2

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ARANGE
PurposeCommandQuery
Classic
Arguments

Read existing AurtoRange range or create a new AutoRange range.
“ARANGE Range, unit, mode (,RptLabel)”“ARANGE?”“ARANGE= Range, units, mode (,RptLabel)”“ARANGE”
Range
The AutoRange maximum pressure. Cannot be negative.
Unit:
The unit of measure of the Range argument.
Mode:
The measurement mode of the Range argument:“A” for absolute“G” for gauge“N” for negative gauge

Note
Measured pressure values are returned with “g” toidentify measurement mode for both gauge and negative
gauge measurement modes.
RptLabel:(optional)

Remarks

Example(enhanced)
Example(classic)
Example(enhanced)
Example(classic)
Example(enhanced)
ErrorsOne of the Internal or External RPTs that is available.
“IH”:
Internal, Hi Q-RPT“IL”:
Internal, Lo Q-RPT“X1H”: External RPM4, Hi Q-RPT“X1L”: External RPM4, Lo Q-RPTThe ARANGE command is used to define a PPC4 range by specifying a desired unit ofmeasure, measurement mode and maximum pressure, and have the PPC4 pick the best
available Q-RPT and make operational adjustments to optimize that range. Available Q-RPTs
may be determined by the use of the “RPT” command to search for external RPM4
devices or use of the [RPT] function key.
The optional “RptLabel” argument can be used to specify which Q-RPT you wish to use
for the AutoRange range instead of allowing the PPC4 to pick the best Q-RPT. By using
this option you can override the internal logic that picks the most suitable Q- RPT. This Q-RPT
must have been previously found using the “RPT” command, [RPT Search] or <RPT> andmust be valid for the maximum pressure and measurement mode specified.
The reply indicates the current range data, including the RptLabel used for the range.
If a water column unit (inH2O, mH2O, mmH2O) is specified for the pressure unit ofmeasure, the temperature reference can be given after the unit text. For example,“inH2O4”, “inH2O20” or “inH2O60” corresponds to inH2O at 4 °C, 20 °C or 60 °F. If notemperature is specified, a default of 20 °C is assumed. There is no indication of thetemperature reference in the reply.
Cmd sent:“ARANGE?”(read the current range in the current units)
Query reply:“100.00, psi, A, IH”
Cmd sent:“ARANGE”(read the current range in the current units)
Query reply:“100.00, psi, A, IH”
Cmd sent:“ARANGE? 250, inWa4, G (range of 250 inWa @ 4 °C in gauge mode)ndQuery reply:“250.000 inWa, G, X2H”
(Hi RPT of 2 external RPM4 used)
Cmd sent:“ARANGE=250, kPa, G(set a range of 250 kPa in gauge mode)st
Query reply:“250.00 kPa, G, X1L”
(Lo RPT of 1 external RPM4 used)“ARANGE 50, psi, A, X1L (set a range of 50 psi in absolute mode on
Cmd sent:st
Lo RPT of 1 RPM4)“50.000 psi, A, X1L”
(No reply if IEEE-488)
Query reply:
ERR# 4:
ERR# 5:See Also

RPT previously found not detected. Usually occurs when the external
RPM4(s) have been disconnected since the last RPT “search”
RPT previously found not the same as now found. Usually occurs whenthe external RPM4(s) connections to the PPC4 have been changed
since the last RPT “search”.
“Range“ maximum pressure exceeds available RPTs or is negative.
Cannot Range to ‘0’ with absolute units.
Cannot Range to ‘0’ with gauge units.
Correct type of RPT for the selected “Mode” is not available.

ERR# 6:
ERR# 19:
ERR# 20:
ERR# 29:“RPT”, “RANGE”
3.2.8. 3.2.5, 3.2.6, 3.2.11

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ATM
PurposeReads the next measured pressure from PPC4’s on-board barometer (if present).

Query“ATM?”Classic“ATM”

Remarks

The atmospheric pressure as measured by the PPC4 on-board barometer is returned in
the current pressure units (always absolute). This measurement is followed by the units
text. Not all PPC4s are equipped with an on-board barometer.

ExampleQuery sent:“ATM?”(enhanced)

Query reply:“97.12348 kPaa”

Example

Sent:

“ATM”

(classic)

Reply:“97.12384 kPaa”

Errors

ERR# 23:

PPC4 is not equipped with a barometer.

See Also

3.2.27.3

AUTOPURGE
PurposeRead or set the status of the automatic purge function.

Command“AUTOPURGE n”

Query“AUTOPURGE?”Classic“AUTOPURGE=n”

Default“AUTOPURGE 0”

Argumentsn:“AUTOPURGE”’0’ To disable AUTO mode.
’1’ To enable AUTO mode.
Remarks

The PPC4 can automatically control the external SPLT functions to purge the test systembefore running a test, if desired.

ExampleCmd sent:“AUTOPURGE 1”(enhanced)

Query reply:“1” (No reply if IEEE-488)

ExampleCmd sent:(enhanced)

Query reply:“1”

ExampleSent:“AUTOPURGE=1”(classic)

Query reply:“AUTOPURGE=0”

Errors

ERR# 6:

The argument was other than a ‘0’ or a ‘1’.

See

3.2.17, 3.2.27.4

AUTOVAC
PurposeRead or set the status of the automated Control Ref determination mode.

Command“AUTOVAC n”

Query“AUTOVAC?”

Classic“AUTOVAC=n”“AUTOPURGE 1”“AUTOVAC”
Default“AUTOVAC 1”

Argumentsn:’0’ To disable AUTO mode. (“VAC” cmd determines status)’1’ To enable AUTO mode. This will override the manual selection.

Remarks

At low pressures, PPC4 control is affected by whether the EXHAUST port is open toatmosphere or connected to vacuum. The PPC4 has an internal sensor that can be used
to automatically determine if the EXHAUST port is open to atmosphere or to a vacuum.
You can disable it to manually override it. It is recommended to use the “VAC” command
to disable this feature instead of the “AUTOVAC=0” command, as you can also specify
vacuum or atmospheric reference at the same time with the VAC command.

ExampleCmd sent:“AUTOVAC 1”(enhanced)

Query reply:“1” (No reply if IEEE-488)

ExampleCmd sent:“AUTOVAC 1”(enhanced)

Query reply:“1”

ExampleSent:“AUTOVAC=0”(classic)

Query reply:“AUTOVAC=0”

Errors

ERR# 6:

The argument was other than a ‘0’ or a ‘1’.

See Also“VAC”
3.2.27.2

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PPC4™ OPERATION AND MAINTENANCE MANUALAUTOZERO
PurposeRead or set the status of the AutoZ function.

Command“AUTOZERO n”

Query“AUTOZERO?”Classic“AUTOZERO=n”

Default“AUTOZERO 1”’0’ Autozero OFFn:’1’ Autozero ON
The PPC4 AutoZ function can be turned ON and OFF. There is a separate AutoZ flag forthe gauge and absolute modes for each RPT. This command sets the AutoZ status forthe current mode of the active internal or external RPT only.

“AUTOZERO”
Arguments
Remarks

ExampleCmd sent:“AUTOZERO 0”(enhanced)

Query reply:“0”

ExampleCmd sent:“AUTOZERO? 0”(enhanced)

Query reply:“0”

ExampleSent:“AUTOZERO=1”(classic)

Query reply:“AUTOZERO=0”

Errors

ERR# 6:

The argument was other than a ‘0’ or a ‘1’.

See Also“ZOFFSET”, “MMODE”(No reply if IEEE-488)

3.2.22
CALAMB
PurposeRead or set the on-board barometer calibration coefficients.

Command“CALAMB adder, mult, CalDate”

Query“CALAMB?”Classic“CALAMB=adder, mult, CalDate”

Defaults“CALAMB = 0.0, 1.0, 19800101”

Arguments

Adder:The Barometer calibration adder (PA).In Pascal.

Mult:

The Barometer calibration multiplier (PM) from 0.1 to 100.

CalDate:The date of the calibration in the format “YYYYMMDD”“CALAMB”

Remarks

The barometer calibration information can be accessed with this program message. Using thisprogram message overwrites the current calibration coefficients, so caution must be used.
Changes made take effect immediately.

ExampleCmd sent:“CALAMB? 2.1, 1.000021, 20011201”(enhanced)

Query reply:“

ExampleSent:“CALAMB=2.1, 1.000021, 20011201”(classic)

Reply:“

Errors

ERR# 6:

One of the arguments is out of range.

See Also

3.2.27.3, 7.3

2.10, 1.000021, 20011201”(No reply if IEEE-488)

2.1, 1.000021, 20011201”

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COM1
PurposeRead or set the RS232 settings for the COM1 port.

Command“COM1 baud, parity, data, stop”

Query“COM1?”Classic“COM1=baud, parity, data, stop”“COM1”

Arguments

Baud:

The baud rate. This may be ’2400’,’4800’, ‘9600’ or ‘19200’.

Parity:The data parity. This may be ‘O’ for odd, ‘E’ for even, or ‘N’ for none.

Data:

The number of data bits. This may be ‘7’ or ‘8’.

Stop:

The number of stop bits. This may be ‘1’ or ‘2’.

Defaults“COM1 2400,E,7,1”

Remarks

The COM1 port is used to communicate to the PPC4. When the COM1 port configuration of
the PPC4 is changed, the program message reply (COM1 use only) is sent at the old COM1
settings, but all subsequent communications are accomplished at the new COM1 settings.
A 200ms or longer delay after receiving the reply to this command will ensure that the PPC4
has changed the COM port settings and is ready for communications at the new settings.

ExampleCmd sent:“COM1 9600,N,8,1”(enhanced)

Query reply:“9600,N,8,1”

ExampleCmd sent:“COM1? 9600,N,8,1”(enhanced)

Query reply:“9600,N,8,1”

ExampleSent:“COM1=9600,N,8,1”(classic))

Reply:“9600,N,8,1”

Errors

ERR# 7:

Missing or improper program message argument(s).

See Also“PASSTHRU”(No reply if IEEE-488)

3.2.24
COM2
PurposeRead or set the RS232 settings for the COM2 port.

Command“COM2 baud,parity,data,stop”

Query“COM2?”Classic“COM2= baud,parity,data,stop”

Arguments

baud:

The baud rate. This may be ’2400’,’4800’, ‘9600’ or ‘19200’.

parity:The data parity. This may be ‘O’ for odd, ‘E’ for even, or ‘N’ for none.

Data:

The number of data bits. This may be ‘7’ or ‘8’.

stop:

The number of stop bits. This may be ‘1’ or ‘2’.

“COM2”

Defaults“COM2 2400,E,7,1”

Remarks

COM2 is generally used to connect DHI RPM4 external measurement devices. The COM2
port can also be used to allow the host computer to communicate through the PPC4 to an
additional device connected to COM2. This can be useful if the host computer does not have
2 serial ports available.

ExampleCmd sent:“COM2 9600,N,8,1”(enhanced)

Query reply:“9600,N,8,1” (No reply if IEEE-488)

ExampleCmd sent:“COM2? 9600,N,8,1”(enhanced)

Query reply:“9600,N,8,1”

ExampleSent:“COM2=9600,N,8,1”(classic)

Reply:“9600,N,8,1”

Errors

ERR# 7:

Missing or improper program message argument(s).

See Also“#”, “PASSTHRU”
3.2.24

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DATE
PurposeRead or set the PPC4 date.

Command“DATE date”

Query“DATE?”Classic“DATE= date”

Arguments

date:

Remarks

The PPC4 has an internal real time calendar clock. It is used for date stamping calibrations.
The reply is always in the YYYYMMDD format.

ExampleCmd sent:“DATE 20030115”(enhanced)

Query reply:“20030105” (No reply if IEEE-488)

ExampleCmd sent:“DATE? 20030105”(enhanced)

Query reply:“20020105”

Errors

ERR# 7:

Missing or improper program message argument(s).

See Also“TIME”“DATE”The date in the numerical only format YYYYMMDD.

3.2.26.3
DF
PurposeDecrease the pressure quickly (fast).

Command“DF n”Classic“DF=n”

Arguments‘0’

Closes the fast down valve.

‘1’

Opens the fast down valve.

Remarks

Opening the fast down valve causes the pressure to decrease quickly.

ExampleCmd sent:“DF 1”(enhanced)

Reply:“1”

ExampleCmd sent:“DF? 1”(enhanced)

Reply:“1”

ExampleSent:“DF=1”(classic)

Reply:“DF=1”

Errors

ERR# 6:

See Also“IF” , “DS”, “IS”, “IP”, “DP”,(no reply if IEEE-488)

The n argument is a ‘0’ or a ‘1’.

Figure 31
DISPUNCn
PurposeRead or set the Q-RPT uncertainty display mode.

Command“DISPUNCn Enable, Mode”

Query“DISPUNCn?”

Classic“DISPUNCn=Enable, Mode”

Defaults“DISPUNCn = 1, 1”

Suffixn:

Arguments

Enable:’0’ or ‘1’ to disable or enable the uncertainty display.

Mode:‘0’ or ‘1’ to display measured ro delivered pressure uncertainty (optional).

“DISPUNCn”‘1’ to access the IH RPT settings‘2’ to access the IL RPT settings

Remarks

The Mode argument is optional, so that the display can be enabled or disabled withoutchanging the mode.

ExampleCmd sent:“DISPUNC 1, 1”(enhanced)

Query reply:“1, 1”

ExampleSent:“DISPUNC=0”(classic)

Reply:“0, 1”

Errors

ERR# 6:

One of the arguments is out of range.

See Also“PCALUNC” command(No reply if IEEE-488)

3.2.29Page 148

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DP
PurposeDecrease the pressure slowly a given amount using the slow speed.

Command“DP n”Classic“DP=n”

Argumentsn:Remarks

The slow speed will be used for a calculated amount of time (up to 5 seconds) to create thedesired change. The PPC4 will not attempt to control the pressure to a target, so the change inpressure will be approximate. This is the equivalent of using .

ExampleCmd sent:“DP 2”(enhanced)

Reply:“2.000 kPa”

ExampleCmd sent:“DP? 2”(enhanced)

Reply:“2.000 kPa”

ExampleSent:“DP=2”(classic)

Reply:“2.000 kPa”

Errors

ERR# 6:

The n argument is not within given limits.

See Also“IP”, “DS”, “IS”, “DF”, “IF”

The decrease in pressure desired (current pressure units). This can be from0 to 2 % FS of the active range.

(no reply if IEEE-488)

3.2.1
DRVn
PurposeRead or set the status of external electrical drivers.

Command“DRVn x”

Query

“DRVn?”Classic“DRVn=x”“DRVn”

Argumentsn:

The driver to operate. This can be from 1 to 8.

x:

The state to change the driver to; ‘0’ to de-activate it, ‘1’ to activate it.

Remarks

The PPC4 control has eight optional external drivers. Driver is used by the optional Purge
function.

ExampleCmd sent:“DRV1 1”(enhanced)

Query reply:“1” (No reply if IEEE-488)

ExampleCmd sent:“DRV2? 1”(enhanced)

Query reply:“1”

ExampleSent:“DRV1=1”(classic)

Reply:“DRV1=1”

Errors

ERR# 6:

The n or x arguments are not within given limits.

See Also

3.2.23

DS
PurposeDecrease the pressure slowly.

Command“DS n”Classic“DS=n”

Argumentsn:Remarks

Opening the slow down valve causes the pressure to decrease slowly.

ExampleCmd sent:“DS 1”(Enhanced)

Reply:“1” (no reply if IEEE-488)

ExampleCmd sent:“DS? 1”(Enhanced)

Reply:“1”

ExampleSent:“DS=1”(Classic)

Reply:“DS=1”

Errors

ERR# 6:

The n argument is a ‘0’ or a ‘1’.

See Also“IS”, “DF”, “IF”, “DP, “IP”

‘0’ Closes the slow down valve.
‘1’ Opens the slow down valve.

Figure 31

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ERR
PurposeRead the new available error message from the Error Queue.

Query“ERR?”Classic“ERR”

Remarks

This program message obtains additional details about an error that has occurred. If the user
receives an “ERR# nn” reply, or the enhanced mode is enabled using the IEEE-488 interface andan error has been detected, the error is put into a FIFO Error Queue. The “ERR” program
message pulls and replies the oldest error message available. “OK” is replied if there are no error
messages left.

ExampleQuery sent:“ERR?”(enhanced):

Query reply:“Numeric argument missing or out of range”

Example

Sent:

“ERR”

(classic)

Reply:“Numeric argument missing or out of range”

See Also

6.5.2

GPIB
PurposeRead or set the GPIB interface address.

Command“GPIB addr”

Query“GPIB?”Classic“GPIB=addr”

Defaults“GPIB 10”

Arguments

addr:

Remarks

The GPIB address is changed following the reply of this command. Each device on a GPIB
interface bus requires a unique address.

ExampleCmd sent:“GPIB 21”(enhanced)

Query reply“21”

ExampleCmd sent:“GPIB? 21”(enhanced)

Query reply“21”

ExampleSent:“GPIB=21”(classic)

Reply:“21”

Errors

ERR# 6:

The argument is not within given limits.

See Also:

3.2.24HEAD
PurposeRead or set the fluid head settings.

Command“HEAD h,u,f”

Query“HEAD?”Classic“HEAD=h,u,f”

Defaults“HEAD 0,cm,N2”

Argumentsh:

The height of the test in relation to the PPC4. This is positive if the test
is above the PPC4, or negative if below the PPC4. This value can be between- 9999 and 9999. Setting this value to ‘0’ disables the head correction.

u:

The height units. This must be “in” or “cm”.

f:

The fluid type. This must be “N2”, “Air”, “He” or “User”.

“GPIB”
The address of the GPIB488 interface (1 to 31)(No reply if IEEE-488)“HEAD”

Remarks

The PPC4 can make a fluid head correction to allow it to display the pressure at the level ofthe device under test instead of at the level of the PPC4.

ExampleCmd sent:“HEAD 10,in,N2”(enhanced)

Query reply:“10, in, N2”

ExampleSent:“HEAD=10,in,N2”(classic)

Reply:“10, in, N2”

Errors

ERR# 6:

The arguments are not within given limits.

See Also:

3.2.16

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HS
PurposeRead or set the automated pressure control hold limit as a pressure value.

Command“HS hold”

Query

“HS?”

Classic“HS=hold”“HS”
The hold limit in the current pressure unit of measure.

Arguments

Hold:

Remarks

Errors

The hold limit can be read and set as a pressure.
“HS .1”
Cmd sent:“0.1 kPa”(No reply if IEEE-488)
Query reply:“HS? .1”
Cmd sent:“0.1 kPa”
Query reply:“HS=0.1”
Sent:“0.1 kPa”
Reply:The ‘hold’ argument was invalid.
ERR# 6

See Also“HS%”

Example(enhanced)
Example(enhanced)
Example(classic)

3.2.2 , 3.2.13
HS%
PurposeRead or set the automated pressure control hold limit for as a percent of range span.

Command“HS% hold”

Query“HS%?”Classic“HS%=hold““HS%”

Arguments

hold:

Remarks

The hold limit can be read and set as a pressure or as a percent of the span.

The hold limit in % span of the active range.

ExampleCmd sent:“HS .01”(enhanced)

Query reply:“0.0100 %”ExampleCmd sent:“HS? .01”(enhanced)

Query reply:“0.0100 %”ExampleSent:“HS=.01”(classic)

Reply:“0.0100 %”Errors

ERR# 6The ‘hold’ argument was invalid.

See Also“HS”(No reply if IEEE-488)

3.2.2 , 3.2.13
ID
PurposeRead or set the user defined instrument identification label.

Command“ID string”

Query

“ID”

Classic“ID=string”“ID”

Arguments

String:An alphanumeric string up to 12 characters long.

Remarks

The user defined ID label can be used to allow the user to “tag” the PPC4 with a unique identifier.
This ID is stored in non-volatile memory and cannot be erased by a power failure, system fault or
reset

ExampleCmd sent:“ID PPCK #A01”(enhanced)

Query reply“PPCK #A01”

ExampleCmd sent:“ID PPCK? #A01”(enhanced)

Query reply“PPCK #A01”

ExampleSent:“ID=PPCK #A01”(classic)

Reply:“PPCK #A01”

Errors

ERR# 6The ‘string’ argument was longer than 12 char.

See Also

3.2.27.1

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IF
PurposeIncrease the pressure quickly (fast).

Command“IF n”Classic“IF=n”

Argumentsn:Remarks

Opening the fast up valve causes the pressure to increase quickly. Care must be used, as thepressure will not stop increasing until the valve is closed, or the upper limit is exceeded.

ExampleCmd sent:“IF 1”(enhanced)

Reply:“1”

ExampleCmd sent:“IF? 1”(enhanced)

Reply:“1”

ExampleSent:“IF=1”(classic)

Reply:“IF=1”

Errors

ERR# 6:

The n argument is a ‘0’ or a ‘1’.

See Also“DF”, “IS” , “DS”, “IP”, “DP”,‘0’ Closes the fast up valve.
‘1’ Opens the fast up valve.

(no reply if IEEE-488)

Figure 31
IP
PurposeIncrease the pressure a given amount using the slow speed.

Command“IP n”Classic“IP=n”

Argumentsn:Remarks

The slow speed will be used for a calculated amount of time (up to 5 seconds) to create thedesired change. The PPC4 will not attempt to control the pressure to a target, so the change inpressure will be approximate. This is the equivalent of using .

ExampleCmd sent:“IP 2”(enhanced)

Reply:“2.000 kPa”

ExampleCmd sent:“IP? 2”(enhanced)

Reply:“2.000 kPa”

ExampleSent:“IP=2”(classic)

Reply:“2.000 kPa”

Errors

ERR# 6:

The n argument is not within given limits.

See Also“DP”, “IF” , “DF”, “IS”, “DS”

The increase in pressure desired (current pressure units). This can be from0 to 2 % FS of the active range.

(no reply if IEEE-488)

3.2.1
IS
PurposeIncrease the pressure slowly.

Command“IS n”Classic“IS=n”

Argumentsn:Remarks

Opening the slow up valve causes the pressure to increase slowly. Care must be used, as thepressure will not stop increasing until the valve is closed, or the upper limit is exceeded.

ExampleCmd sent:“IS 1”(enhanced)

Reply:“1”

ExampleCmd sent:“IS? 1”(enhanced)

Reply:“1”

ExampleSent:“IS=1”(classic)

Reply:“IS=1”

Errors

ERR# 6:

The n argument is a ‘0’ or a ‘1’.

See Also“DS” , “IF” , “DF”, “IP”, “DP”

‘0’ Closes the slow up valve.
‘1’ Opens the slow up valve.

(no reply if IEEE-488)

Figure 31

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6. REMOTE OPERATION

L2 / L3
PurposeRead or set the type of program command format to use (classic or enhanced).

Command“L2” enables “classic” mode
“L3” enables “enhanced” mode

Defaults“L2”

Remarks

The user can select the type of remote command format using these simplified commands.
There is no query format. This format must agree with the format sent to the RPM4. This
command is a replacement for the “MSGFMT” command.

(Classic mode)

ExampleCmd sent:“L3”(enhanced)

Query reply:“L3”

Example

Sent:

“L2”

(classic)

Reply:“L2”

See Also“MSGFMT”(No reply if IEEE-488)

6.4
LL(=)
PurposeRead or set the lower pressure limit for the active range and measurement mode (negative
gauge measurement mode only).

Command“LL n”Classic“LL=n”

Argumentsn:Remarks

Negative gauge mode in PPC4 has a lower limit. New automated pressure control targets can not
be less than this value. If the pressure exceeds the lower limit, the pressure display flashes, andpressure control is aborted. Manual decreases in pressure are not allowed as long as the pressure
is below the lower limit. Increases in pressure are allowed. This feature should always be used toprevent accidental over (under) pressure of a device under test.

ExampleCmd sent:“LL -4”(enhanced)

Reply:“-4 kPa g”

ExampleCmd sent:“LL? -4”(enhanced)

Reply:“-4 kPa g”

ExampleSent:“LL=-4”(classic)

Reply:“-4 kPa g”

Errors

ERR# 6:

The n argument is invalid.

ERR# 23

The mode must be negative gauge to specify a lower limit.

See Also

The lower pressure limit for the current pressure range in the current unit ofmeasure. Value is always a negative value of gauge pressure.

(no reply if IEEE-488)“UL”
3.2.21

LOCAL
PurposeReturns control to the PPC4 front panel.

Command“LOCAL”

Classic“LOCAL”

RemarkThe REMOTE program message can lock the front panel out completely. The user can return
to local operation by sending the LOCAL program message, sending the IEEE-488 ‘GTL’
command (if in enhanced format), or by cycling PPC4 power.

ExampleCmd sent:“LOCAL”(enhanced)

Reply:“LOCAL”

ExampleCmd sent:“LOCAL?”(enhanced)

Reply:“LOCAL”

ExampleSent:“LOCAL”(classic)

Reply:“LOCAL”

See Also“REMOTE”(no reply if IEEE-488)

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MEM
PurposeRead the status from the power-up memory test.

Query“MEM?”Classic“MEM”

Remarks

The PPC4 system memory stores the user settings (units, resolution, generation settings) andretains them when the unit is OFF. On power-up, this memory is checked. If this memory is
corrupted, all user settings are reset to default , and the MEM status will be set to reflect this.

ExampleQuery sent:“MEM?”(enhanced)

Reply:“0” PPC4 data corrupted and was set to factory defaults.

Example

Sent:

“MEM”

(classic)

Reply:“MEM=0” PPC4 data corrupted and was set to factory defaults.

“1” The memory was found to be OK on power-up.

“MEM=1” The memory was found to be OK on power-up.
See Also

3.2.27.5

MODE
PurposeRead or set the automated pressure control mode.

Command“MODE n”

Query

“MODE?”Classic“MODE=n”“MODE”

Argumentsn:’0’ for static pressure control.
’1’ for dynamic pressure control.

Remarks

The method which the PPC4 controls pressure is selected with the “MODE” program message.
When the control mode is set, control parameters go to default parameters for that range.
The control mode setting is range dependent.

ExampleCmd sent:“MODE 1”(enhanced)

Query reply:“1”

ExampleCmd sent:“MODE? 1”(enhanced)

Query reply:“1”

ExampleSent:“MODE=1”(classic)

Reply:“MODE=1”

Errors

ERR# 6

The argument is invalid.

See Also“HS”, “SS”

(No reply if IEEE-488)

3.2.13, 3.2.2

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MMODE
PurposeRead or change the active measurement mode.

Command“MMODE=mode”

Query“MMODE”

Classic“MMODE=mode”“MMODE ”

Arguments

Mode:"A" Absolute mode
"G" Gauge mode
"N" Negative gauge mode

Note
Measured pressure values are returned with “g” to identify
measurement mode for both gauge and negative gaugemeasurement modes.
Remarks

The active RPT or an AutoRange range should selected before setting measurement mode
since measurement mode is range specific. The measurement mode can also be set using
the “UNIT” command but the “UNIT” command does not distinguish between gauge andnegative gauge while the “MMODE” does.

ExampleCmd sent:“MMODE A”(enhanced)

Query reply:“A”

ExampleCmd sent:“MMODE? A”(enhanced)

Query reply:“A”

ExampleCmd sent:“MMODE=G”(enhanced)

Query reply:“G”

Errors

ERR# 6:

Invalid argument text.

ERR# 7:

Abs mode only with altitude units or gauge mode only with gauge RPT.

ERR# 20:

Absolute or negative gauge mode not available with gauge RPT or absolute
RPT with an absolute and negative gauge OFF calibration.

(No reply if IEEE-488)

The current range cannot support gauge mode.
ERR# 53:
See Also

Not available.

“UNIT”
3.2.11MSGFMT
PurposeRead or set the type of program command format to use (enhanced or classic).

Command“MSGFMT n

Query“MSGFMT?”Classic“MSGFMT=n“MSGFMT”

Argumentsn:‘1’ to use the enhanced command format.
‘0’ to use the classic command format.

Defaults“MSGFMT 0”

Remarks

The user can select the type of remote command format to use. This format must agree withthe format sent to the PPC4.
The enhanced query form of this command (“MSGFMT? n”) should always be used to set thedesired format, as it will be accepted regardless of the current format (classic or enhanced).

ExampleCmd sent:“MSGFMT 1”(enhanced)

Query reply:“1”

ExampleCmd sent:“MSGFMT? 1”(enhanced)

Query reply:“1”

ExampleSent:“MSGFMT=1”(classic)

Reply:“MSGFMT=1”

Errors

ERR# 6:

Missing or improper program message argument(s).

See Also

6.4(No reply if IEEE-488)

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NVENT
PurposeRead or set the status of TEST (-) (negative) vent valve (Gxxx or BGxxx Q-RPT only)

Command“NVENT n”

Query“NVENT?”

Classic“NVENT=n”

Default“NVENT AUTO”

Argumentsn:“NVENT”’0’ to close the low vent valve.
’1’ to open the low vent valve.
‘AUTO’ for the PPC4 to automatically open and close the low vent valve.
RemarksA PPC4 with at least one Gxxx or BGxxx Q-RPT has a valve that is used to vent the TEST (-) port.
This valve is normally controlled automatically depending on current PPC4 operation but it can becommanded to open or close using the “NVENT” command. The PPC4 may not immediately open
the negative vent valve when commanded to do so, as it checks to make sure that such an action
will not cause harm to the low pressure Q-RPT.
The reply includes two fields. The first indicates the low vent status. The second indicates whether
the low vent function is AUTO or MANUAL

ExampleCmd sent:“NVENT 0”(enhanced)

Query reply:“0, MANUAL”

ExampleCmd sent:“NVENT? AUTO”(enhanced)

Query reply:“1, AUTO”

ExampleSent:“NVENT=1”(classic)

Query reply:“0, MANUAL”

See Also“VENT”
3.2.27.6

PASSTHRU
PurposeTo allow the host PC to communicate with a device connected to the PPC4 COM2 port.

Command“PASSTHRU n

Query“PASSTHRU?”Classic“PASSTHRU= n”“PASSTHRU”

Argumentsn:

The string to send out of the COM2 port. It must be less than 40 characters long.

Remarks

Generally, the PPC4 COM2 port is used for communication with DHI RPM4s used as PPC4
external measurement devices.
The COM2 port can alternatively be used to communicate to another RS232 device (such as
another PPC4). This allows the user to use one COM port or IEEE-488 port on the host computer
to communicate with the PPC4 and another device. The Command format specifies and sends
the argument. A carriage return and a line feed (<CR><LF>) are added to the string that is sent.
The Query format is used to check the PPC4 COM2 receive buffer to see if a message has been
received on COM2 from the device. The message received by the COM2 port must be terminatedwith a carriage return or a carriage return and a line feed. Only one message is retained by theCOM2 port. The label “COM2:” precedes the message text. If the COM2 receive buffer is empty,
then the reply is just be ‘COM2:”

ExampleCmd sent:“PASSTHRU VER”

(enhanced)

Query reply:“COM2:DH INSTRUMENTS, INC PPC4 VER1.01a”

Query reply:“COM2:” (If the COM2 buffer is empty)

ExampleSent:“PASSTHRU=VER”(classic)

Reply:“COM2:DH INSTRUMENTS, INC PPC4 VER1.01a”

Reply:“COM2:” (If the COM2 buffer is empty)

See Also“#” , “COM2”
6.3.1.1, 6.3.1.2

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6. REMOTE OPERATION

PCAL:IH and PCAL:IL
PurposeRead or set the Q-RPT or utility sensor calibration information for the “IH” (internal high) and“IL” (internal low) RPTs. “IH” is equivalent to “IuH”.

Command“PCAL:IH adder, mult, CalDate, (GaOnly)”“PCAL:IL adder, mult, CalDate, (GaOnly)”

Query“PCAL:IH?”“PCAL:IL?”

Classic“PCAL:IH =adder, mult, CalDate, (GaOnly)”“PCAL:IL =adder, mult, CalDate, (GaOnly}”“PCAL:IH”“PCAL:IL”

Defaults“PCAL:IH = 0.0, 1.0, 19800101, 0”“PCAL:IL = 0.0, 1.0, 19800101, 0”

Arguments

Adder:The RPT calibration adder (PA). In Pascal.

Mult:

The RPT calibration multiplier (PM) from 0.1 to 100.

CalDate:The date of the calibration in the format “YYYYMMDD” by default. The format“YYMMDD” is also be accepted, and the replied format is in the previously
entered format.

GaOnlyOptional “Gauge only” flag. Indicates that the an Axxx Q-RPT is set tooperate in gauge measurement mode only. This field does not apply and isignored for Gxxx and BGxxx Q-RPTs or utility sensors.
‘0’ Absolute, negative gauge and gauge modes are available.
‘1’ Gauge mode only.

Remarks

The user defined pressure calibration information for the specified RPT (IH or IL pressure)can be accessed with this program message. Using this program message overwrites thecurrent calibration coefficients, so caution must be used. If the “GaMode” flag is set and the
RPT is an Axxx Q-RPT, then the RPT will only be allowed to operate in gauge mode.
Changes made using this program message take effect immediately.
The calibration information of DHI RPM4s connected to PPC4 must be adjusted directly on
the RPM4. The information cannot be adjusted through the PPC4.

ExampleCmd sent:“PCAL:LO 2.1, 1.000021, 20011201, 0”(enhanced)

Query reply:“

ExampleCmd sent:“PCAL:LO? 2.1, 1.000021, 20011201, 0”(enhanced)

Query reply:“

ExampleSent:“PCAL:LO=2.1, 1.000021, 20011201, 1”(classic)

Reply:“

Errors

ERR# 6:

One of the arguments is out of range.

See Also

7.2

2.10 Pa, 1.000021, 20011201, 0”(No reply if IEEE-488)

2.10 Pa, 1.000021, 20011201, 0”
2.10 Pa, 1.000021, 20011201, 1”

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PPC4™ OPERATION AND MAINTENANCE MANUALPCALUNC:IH and PCALUNC:IL
PurposeRead or set the Q-RPT uncertainty settings used to determine the RPT’s measurement
uncertainty during operation.
Command“PCALUNC:IH Reading, Span, Scale, Head, StabAZon, StabAZoff”“PCALUNC:IL Reading, Span, Scale, Head, StabAZon, StabAZoff”

Query“PCALUNC:IH?”

Classic“PCALUNC:IH=Reading, Span, Scale, Head, StabAZon, StabAZoff”“PCALUNC:IL?”“PCALUNC:IL=Reading, Span, Scale, Head, StabAZon, StabAZoff”“PCALUNC:IH”“PCALUNC:IL”
Defaults“PCALUNC:IH = 0.0080, 0.0024, 30, 0.00, 0.0000, 0.005” (Premium Q-RPT)“PCALUNC:IH = 0.0100, 0.0030, 100, 0.00, 0.0000, 0.005”(Standard Q-RPT)“PCALUNC:IH = 0.0, 0.015, 30, 0.00, 0.0000, 0.005" (Full Scale Standard Q-RPT)"PCALUNC:IH = 0.0, 0.015, 10, 0.00, 0.0000, 0.005" (Full Scale Standard Q-RPT BG or G)“PCALUNC:IL = 0.0080, 0.0024, 30, 0.00, 0.0000, 0.005” (Premium Q-RPT)“PCALUNC:IL = 0.0100, 0.0030, 100, 0.00, 0.0000, 0.005”(Standard Q-RPT)"PCALUNC:IL = 0.0, 0.015, 30, 0.00, 0.0000, 0.005" (Full Scale Standard Q-RPT)"PCALUNC:IL = 0.0, 0.015, 10, 0.00, 0.0000, 0.005" (Full Scale Standard Q-RPT BG or G)
Arguments

Reading:

The % of reading uncertainty component (%).

Span:

The % of range span uncertainty component (%).

Scale:The miminum scaling limit (%).

Head:

The uncertainty head height in the current head units.

StabAZon:

The stability uncertainty component when auto zero is ON.

StabAZoff:

The stability uncertainty component when auto zero is OFF.

Remarks

Use the PPC4 uncertainty function to obtain a re-time update of delivered, or measured
pressure uncertainty. The uncertainty feature is available for Q-RPTs only.

ExampleCmd sent:“PCALUNC:IH=.005, .001, 50, 0, 0, .01”

(enhanced)

Query reply:“0.0050, 0.0010, 50.0, 0.00, 0.0000, 0.0100”

ExampleSent:“PCALUNC:IL= .005, .001, 50, 0, 0, .01”

(classic)

Reply:“0.0050, 0.0010, 50.0, 0.00, 0.0000, 0.0100”

Errors

ERR# 6:

One of the arguments is out of range.

See Also“DISPUNC” command(No reply if IEEE-488)“HEAD” command
3.2.29, 7.2.7.3
PR
PurposeRead the next available pressure.

Query

“PR?”

Classic“PR”

Remarks

The next available pressure value for the active Q-RPT or utility sensor is read in the current
pressure units. The data returned also contains Ready/Not Ready information, and the pressure
unit of measure and measurement mode.
The reply field is always 20 characters long. The first 3 characters of the reply are reserved for the
ready status (R or NR). The ready status is described in the “SR” program message. The
pressure value and pressure unit of measure are right justified in this field.
After receiving this program message, the PPC4 replies back with the data after a new pressure
measurement cycle is complete. This can take up to 1.5 seconds.

ExampleQuery sent:“PR?”(enhanced)

Query reply:“R

ExampleQuery sent:“PR”(classic)

Reply:

See Also“PRR”, “QPRR”, “SR”

1936.72 kPaa”“R

1936.72 kPaa”

3.2.3

Page 158

6. REMOTE OPERATION

PRR
PurposeRead the next available pressure, rate, on-board barometer reading, control status, and the
QRPT uncertainty.

Query“PRR?”Classic“PRR”

Remarks

The next available Ready condition, Q-RPT or utility sensor pressure, rate of pressure change,
barometric pressure, generation status and Q-RPT uncertainty is replied in the current
pressure unit of measure. Each data field is separated by a comma, and is returned in thefollowing order up to 1.2 seconds after the command is received:
ready, pressure UNITS, rate UNITS/s, atm UNITS, status, uncert UNITS
Here are the field descriptions:ready:‘R’ if the current pressure Ready criteria has been met,
‘NR’ if the criteria has not been met (see the “SR” program message).

pressure:

The measured pressure for the active Q-RPT or utility sensor in the current
pressure unit. This is followed by the current pressure unit.

rate:

The measured rate of pressure change for the active Q-RPT or utility sensor
in the current pressure unit per second. This is followed by the current
pressure unit of measure.

atm:

The pressure measured by the PPC4 on-board barometer in the current
pressure unit (and always absolute). This is followed by the current
pressure unit. Not all PPC4s are equipped with an on-board barometer.
This field is “NONE” if the PPC4 is not equipped with an on-board barometer.

status:Generation status. Similar to the reply of the STAT command. Can be asum of the following states::
0

The system is not generating or holding a pressure or vented.

1

A new generation is preparing to start.

2

Quick ramping to the target.

4

Quick pulsing to the target.

8

Slow ramping to the target.

16

Slow pulsing to the target.

32

Reached the target, will re-adjust as needed to stay ready.

64

Quick ramping to a vent condition.

128

Executing a purge operation.

256

Quickly decreasing the pressure to reach a hard vacuum.

512

System is vented

1024

A new target has been requested but generation has not started.

2048

PWM low pressure control

4096

Dynamic pulsing is being used to control a pressure.

8291

Static pulsing is being used to control a pressure.

16394

Low pressure pulsed control is active.

32768

Very low pressure pulsed control is active.

65536

Determining external volume

uncert:The uncertainty is calculated as the measured uncertainty or the delivered
uncertainty, depending on the current setting as determined by the
DISPUNC command. Always returned as ‘0’ for utility sensors.

ExampleQuery sent:“PRR?”(enhanced)

Query reply:“R,2306.265 kPaa,0.011 kPa/s,97.000 kPaa, 0, 0.0034 kPa”

ExampleQuery sent:“PRR”(classic)

Reply:“R,2306.265 kPaa,0.011 kPa/s,97.000 kPaa, 0, 0.0034 kPa”

See Also“PR”, “QPRR”, “SR”, “DISPUNC”“R,2306.265 kPaa,0.011 kPa/s, NONE, 0, 0.0034 kPa ” (no barometer)

3.2.2, 3.2.27.3, 3.2.29

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PPC4™ OPERATION AND MAINTENANCE MANUAL

PS
PurposeSet a new target pressure and start a new pressure generation cycle. Allows the test volume
to be specified which causes the pressure generation cycle to be executed omitting theautomated control configuration routine.

Command“PS n (,v)”

Classic“PS=n (,v)”

Argumentsn:

The target pressure in the current pressure units.

v:

The volume of the system connected to the PPC4 TEST(+) port in cm (cc).
This argument is optional and should be used only to reduce pressure
setting time in know volumes.

Remarks

3

The PPC4 sets the specified target pressure using the current control settings and mode.
Control continues until a new target pressure is set, the PPC4 goes into LOCAL mode, or an“ABORT” program message is executed. If the given target is ‘0’ and the pressure units aregauge, the PPC4 vents.
The “PR?”, “PRR?”, “STAT?”, or “SR?” program message queries can be used to monitor the
progress of the pressure setting routine.
If the optional “v” argument is used, the PPC4 does not perform its test volume determination
routine at the beginning of the pressure setting procedure, but instead uses the volume
specified for the pressure generation. This can reduce pressure set times when operating into
a consistent volume since the configuration routine takes 5 to 6 seconds to execute. The “v”
argument should only be used in automated conditions, where the test volume is constant andthe configuration does not change. This argument is only an approximation value, and it may
be adjusted empirically for correct operation. A higher “v” setting speeds up the generation
with a higher risk of significant control overshoot. A lower “v” setting slows down thegeneration and reduces overshoot. Note: When using a BG15K or G15K low gauge pressure QRPT with a DVU, the volume size specified should NOT include the DVU volume.

ExampleCmd sent:“PS 1000”(enhanced)

Reply:“1000.000 kPa a “

ExampleCmd sent:“PS? 1000”(enhanced)

Reply:“1000.000 kPa a “

ExampleSent:“PS=1000, 75”(classic)

Reply:“1000.000 kPa a “Errors

ERR# 6

The target pressure is out of range.

See Also“PR”, “PRR”, “STAT”, “SR”, “QPRR”(no reply if IEEE-488)(includes test volume definintion)

3.2.2, 3.2.12
PSF
PurposeSet a new target pressure, using only the fast control valve(s) and aborting pressure control
once the pressure target is reached..

Command“PSF n”

Classic“PSF=n”

Arguments

N:

Remarks

The PPC4 sets the given target pressure using just the fast speed, and stops controlling when
the pressure has reached or passed the given target. The system does not attempt tomaintain the target pressure.

The target pressure in the current pressure unit of measure.

The “PR?”, “PRR?”, “STAT?”, or “SR?” program message queries can be used to monitor the
progress of the generation.
ExampleCmd sent:“PSF 1000”(enhanced)

Reply:“1000.000 kPaa (no reply if IEEE-488)

ExampleSent:“PSF=1000”(classic)

Reply:“1000.000 kPaa

Errors

ERR# 6

The target pressure is out of range.

See Also“PR”, “PRR”, “STAT”, “SR”, “PSS”, “PS”
Figure 31

Page 160

6. REMOTE OPERATION

PSS
PurposeSet a new target pressure using only the slow control valve(s) and aborting pressure control
once the target is reached.

Command“PSS n”

Classic“PSS=n”

Arguments

N:

Remarks

The PPC4 sets the given target pressure using just the slow speed, and stops controllingwhen the pressure has reached or passed the given target. The system does not attempt tomaintain the target pressure.

The target pressure in the current pressure units.

The “PR?”, “PRR?”, “STAT?”, or “SR?” program message can be used to monitor the
progress of the generation.
ExampleCmd sent:“PSS 1000”(enhanced)

Reply:“1000.000 kPaa”

ExampleCmd sent:“PSS? 1000”(enhanced)

Reply:“1000.000 kPaa”

ExampleSent:“PSS=1000”(classic)

Reply:“1000.000 kPaa”

Errors

ERR# 6

The target pressure is out of range.

See Also“PR”, “PRR”, “STAT”, “SR”, “PSF”, “PS”
Figure 31

Page 161(no reply if IEEE-488)

PPC4™ OPERATION AND MAINTENANCE MANUAL

QPRR
PurposeQuickly read the last known pressure, rate, on-board barometer reading, control status and
QRPT uncertainty.

Query“QPRR?”Classic“QPRR”

Remarks

The last known Ready condition, Q-RPT or utility sensor pressure, rate of pressure change,
barometric pressure, generation status and Q-RPT uncertainty is replied in the current
pressure unit of measure. Each data field is separated by a comma, and is returned in thefollowing order:
ready, pressure UNITS, rate UNITS/s, atm UNITS, status, uncert UNITS
Here are the field descriptions:ready:‘R’ if the current pressure Ready criteria has been met,
‘NR’ if the criteria has not been met (see the “SR” program message).

pressure:

The measured pressure for the active Q-RPT or utility sensor in the current
pressure unit. This is followed by the current pressure unit.

rate:

The measured rate of pressure change for the active Q-RPT or utility sensor
in the current pressure unit per second. This is followed by the current
pressure unit of measure.

atm:

The pressure measured by the PPC4 on-board barometer in the current
pressure unit (and always absolute). This is followed by the current
pressure unit. Not all PPC4s are equipped with an on-board barometer.
This field is “NONE”if the PPC4 is not equipped with an on-board barometer.

status:Generation status. Similar to the reply of the STAT command. Can be a sumof the following states:
0

The system is not generating or holding a pressure or vented.

1

A new generation is preparing to start.

2

Quick ramping to the target.

4

Quick pulsing to the target.

8

Slow ramping to the target.

16

Slow pulsing to the target.

32

Reached the target, will re-adjust as needed to stay ready.

64

Quick ramping to a vent condition.

128

Executing a purge operation.

256

Quickly decreasing the pressure to reach a hard vacuum.

512

System is vented

1024

A new target has been requested but generation has not started.

2048

PWM low pressure control

4096

Dynamic pulsing is being used to control a pressure.

8291

Static pulsing is being used to control a pressure.

16394

Low pressure pulsed control is active.

32768

Very low pressure pulsed control is active.

65536

Determining external volume

uncert:The uncertainty is calculated as the measured uncertainty or the delivered
uncertainty, depending on the current setting as determined by the
DISPUNC command. Always returned as ‘0’ for utility sensors.

ExampleQuery sent:“QPRR?”(enhanced)

Query reply:“R,2306.265 kPaa,0.011 kPa/s,97.000 kPaa, 0, 0.0034 kPa”

ExampleQuery sent:“QPRR”(classic)

Reply:“R,2306.265 kPaa,0.011 kPa/s,97.000 kPaa, 0, 0.0034 kPa”

See Also“PR”, “PRR”, “SR”, “DISPUNC”“R,2306.265 kPaa,0.011 kPa/s, NONE, 0, 0.0034 kPa ” (no barometer)

3.2.2, 3.2.27.3, 3.2.29

Page 162

6. REMOTE OPERATIONRANGE (PPC4 version)
PurposeChange the active range to one of the available internal or external default RPT ranges.
Read the active range full scale, pressure unit and measurement mode.

Command“RANGE Rng”

Query

“RANGE?”Classic“RANGE= Rng”

Default“RANGE IH”“RANGE ”
Rng:“IH” for the internal, hi Q-RPT or utility sensor“IL” for the internal lo Q-RPT“X1H” for the first external RPM4, hi Q-RPT“X1L” for the first external RPM4, lo Q-RPT

Remarks

The active RPT must be selected before making changes to settings that are dependent on
the range. The system MUST BE VENTED to change active RPTs.
RPTs selected with this command are used with their full default pressure range. External RPTs
must be found and initialized using the “RPT” command or function key before the can beselected
The reply indicates the active range in psi if the PPC4 is a “US” version or in kPa if the PPC4
is an “SI” version.
Used as a simple query, the active range is returned, which can be an AutoRanged range or adefault range (see “ARANGE” cmd).

ExampleCmd sent:“RANGE IL”(select internal Lo Q-RPT in it’s full default range)(enhanced)

Query reply:“50 psia”(no response in IEEE-488)

ExampleSent:“RANGE=IH”(select internal Hi Q-RPT in it’s full default range)(classic)

Reply:“1000 psia”

ExampleSent:“RANGE=X2H”(classic)

Reply:“500 psia”

ExampleSent:“RANGE”(classic)

Reply:“220 psia”

ErrorsSee Also(select external 2ndRPM4, Hi Q-RPT)(request current range)

ERR# 6:

Invalid Rng argument.

ERR# 22:

System must be vented for the requested operation.

ERR# 38:

The selected RPT is not available.

“ARANGE”, “RPT”
3.2.6, 3.2.9, 3.2.8,

RATE
PurposeRead the next available pressure rate of change.

Query“RATE?”Classic“RATE”

Remarks

The next available pressure rate of change in the current pressure unit per second isreturned.
After receiving this program message, the PPC4 replies back with the data once a newpressure measurement cycle is complete. This can take up to 1.5 seconds.

ExampleQuery sent:“RATE?”(enhanced)

Query reply:“0.01 kPa/s”

ExampleSent:“RATE”(classic)

Reply:“0.01 kPa/s”

See Also“PRR”, “QPRR”

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PPC4™ OPERATION AND MAINTENANCE MANUALREADYCK
PurposeRead or set the Ready check flag.

Command“READYCK 1”

Query“READYCK?”Classic“READYCK=1”

Remarks

The internal ready check flag is cleared whenever the PPC4 reaches a Not Ready (NR)condition. The “READYCK” query returns the status of the flag. The flag is set by sending the“READYCK 1” program message while the PPC4 is in a Ready condition. The “READYCK”
program message query can then be used at a later time to determine whether a Not Readycondition has occurred since the ready check flag was set.

ExampleCmd sent:“READYCK 1”(enhanced)

Query reply:“1” (no reply if IEEE-488)

ExampleCmd sent:“READYCK?”(enhanced)

Query reply:“1”

ExampleCmd sent:“READYCK?”(enhanced)

Query reply:“1” (if PPC4 condition has stayed Ready)“READYCK”“0” (if PPC4 condition has NOT stayed Ready)ExampleSent:“READYCK=1”(classic)

Query reply:“READYCK=1”

ExampleSent:“READYCK”(classic)

Query reply:“READYCK=1” (if PPC4 condition has stayed Ready)“READYCK=0” (if PPC4 condition has NOT stayed Ready)Errors

ERR# 6:

See Also“SR”

Argument is not a ‘0’ or a ‘1’.

3.2.3
REMOTE
PurposeLock out the front panel keypads during remote operation.

Command“REMOTE”

Classic“REMOTE”

Remarks

The PPC4 goes into remote mode whenever communications take place. The user canreturn to local operation by pressing . The REMOTE program message locks out the front
panel completely. The only way to unlock the front panel after the “REMOTE” command isusing the “LOCAL” program message, the IEEE-488 “GTL” command, or by cycling the PPC4
power.

ExampleCmd sent:“REMOTE”(enhanced)

Reply:“REMOTE” (no reply if IEEE-488)

ExampleCmd sent:“REMOTE?”(enhanced)

Reply:“REMOTE”

ExampleSent:“REMOTE”(classic)

Reply:“REMOTE”

See Also“LOCAL”

Page 164

6. REMOTE OPERATION

RES
PurposeTo read or set the pressure display resolution for the active range.

Command“RES n”

Query

“RES”

Classic“RES=n”

Default“RES 0.001”“RES”
Argumentsn:Remarks

The pressure display resolution is defined as % span of the active range. The setting isseparate for each range, and changes as the range is changed.

The pressure display resolution in % span of the current RPT range (0.0001 to 1 % FS).

ExampleCmd sent:“RES .01”(enhanced)

Query reply:“0.01”

ExampleCmd sent:“RES? .01”

(enhanced)

Query reply:“0.01”

ExampleSent:“RES=.01”(classic)

Reply:“0.01”

Errors

ERR# 6

The argument is invalid.

See Also

3.2.19(No reply if IEEE-488)

RESET
PurposeReset the user’s settings to factory defaults.

Command“RESET”

Classic“RESET”

Remarks

The PPC4 has user settings (units, resolution, control modes, etc.) that can be reset to factory
defaults. System calibration coefficients and communications settings are not affected. The
remote “RESET” program message corresponds to the front panel “Reset Settings.” The reset
cycle takes up to 5 seconds to complete and involves a power cycle of the PPC4. Remotecommunications should not take place during this period.

ExampleCmd sent:“RESET”(enhanced)

Reply:“RESET”

ExampleCmd sent:“RESET?”(enhanced)

Reply:“RESET”

ExampleSent:“RESET”(classic)

Reply:“RESET”

See Also

3.2.25.1(no reply if IEEE-488)

RETURN
PurposeStart a new pressure setting sequence equivalent to the “PS” command using the last target
pressure.

Command“RETURN”

Classic“RETURN”

Remarks

The “RETURN” program message starts a new pressure setting sequence using the current
settings and target pressure. Pressure control continues until a new target pressure is set, the
PPC4 is put into LOCAL mode, or an “ABORT” program message is executed.

ExampleCmd sent:“RETURN”(enhanced)

Reply:“1000.000 kPaa” (no reply if IEEE-488)

ExampleSent:“RETURN”(classic)

Reply:“1000.000 kPaa”

Errors

ERR# 6The current target pressure is invalid.

See Also“PS“, “TP”
3.2.12

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PPC4™ OPERATION AND MAINTENANCE MANUAL

RPT(n)
PurposeRead the available Q-RPT data or initiate the Q-RPT search and initialize process.

Command

“RPT”

Query

“RPT(n)”Classic“RPT”

Default“RPT”

Prefixn“RPT(n)”(optional)

Specify the position locator of the RPT about which to collect information:‘1’ The internal, Hi RPT‘2’ The internal, Lo, Q-RPT‘3’ The first external RPM4, Hi Q-RPT‘4’ The first external RPM4, Lo Q-RPT

Remarks

Up to four Q-RPTs can be available for use in one PPC4 system. Two of these can be internal, andthe other two are external. These Q-RPTs must be identified and initalized before the can be usedby the PPC4. This command allows the search process to be executed (by omitting the prefix ‘n’)
and allows review of the Q-RPTs identified. Note that the search process can take up to 10
seconds to complete, and that the communications settings for the PPC4’s COM2 port and theexternal RPM4 devices should be setup prior to this. If you are querying the unit for information
about a particular Q-RPT Using the prefix ‘n’), then the Q-RPT data found during the execution of
the last search is returned in the following format::
RPTType, RPTLocator, Serial#, RngGa, RngAbs, RptMode
RngLabe:

RPT type label. This label identifies the RPT type and range. This is the samelabel used on the PPC4 front panel screen.

RptLocator: Text field identifying the Q-RPT position in the PPC4 system.
“IH” identifies this as an internal, Hi Q-RPT“IuH” identifies this as an internal, Hi utility sensor“IL” identifies this as an internal, Lo Q-RPT“X1H” identifies this as the first external RPM4, Hi Q-RPT“X1H” identifies this as the first external RPM4, Lo Q-RPT
Serial#:The serial number of the PPC4 or RPM4 in which the Q-RPT is located.

RngGa:The Q-RPT gauge mode range in the current pressure unit.

RngAbs:The Q-RPT absolute mode range in the current pressure unit. “NONE” appears
in the field if the Q-RPT is a Gxxx, BGxxx or Axxx with absolute and negative
gauge modes OFF.

RptMode:‘A’ if Q-RPT is Axxx and supports absolute, gauge and negative gaugemeasurement modes.
‘G’ if Q-RPT is gauge Gxxx or Axxx with absolute and negative gauge modes
OFF and supports only gauge measurement mode.
‘N’ if Q-RPT is BGxxx and supports gauge and negative gauge measurement

modes.
ExampleCmd sent:“RPT?

(find external Q-RPTs in RPM4(s))(enhanced)

Query reply:“OK”(takes up to 10 seconds to reply)

ExampleCmd sent:“RPT(find external Q-RPTs in RPM4(s))(classic)

Query reply:“OK”(takes up to 10 seconds to reply)

ExampleCmd sent:“RPT2?”(enhanced)

Query reply:“A350K, IL, 82345, 35, 50,A”

ExampleCmd sent:“RPT6”(classic)

Query reply:“A7M, IH, 82345, 1000, 1000,A”

ERR# 4:

RPT not previously found

ERR# 10:Invalid prefix.

ErrorsSee Also(Get information on internal, Lo Q-RPT)(Get information on Q-RPT in ext RPM4, Lo position)“ARANGE”, “COM2”
3.2.5, 3.2.8

Page 166

6. REMOTE OPERATIONSCRSAV
PurposeRead or set the front panel display screen saver activation time & type.

Command“SCRSAV n,t”

Query

“SCRSAV?”Classic“SCRSAV=n, t”“SCRSAV”

Argumentsn:

The inactivity period. (minutes) after which screen saver activates.

t:

Optional screen saver type (GUI only):‘0’ Moving pressure screen saver‘1’ DHI screen saver

Default“SCRSAV 10, 0”

Remarks

The PPC4 front panel will dim basic display or switch the GUI to a screen saver pattern after
a period of keyboard and remote inactivity. Setting this value to ‘0’ disables this feature.

ExampleCmd sent:“SCRSAV 30, 1”(enhanced)

Query reply:“30, 1”

ExampleCmd sent:“SCRSAV? 30”(enhanced)

Query reply:“30, 0”

ExampleSent:“SCRSAV=30, 0”(classic)

Reply:“30, 0”Errors

ERR# 6

The argument was invalid.

See Also

3.2.26.1(No reply if IEEE-488)

SN
PurposeTo read the serial number of the PPC4.

Query

“SN?”

Classic“SN”

Remarks

The PPC4 is serialized. The serial number can be read using this program message.

ExampleQuery sent:“SN?”(enhanced)

Query reply:“321”

Example

Sent:

“SN”

(classic)

Reply:“321”

See Also

3.2.27.1

SR
PurposeRead the next available Ready/Not Ready status.

Query

“SR?”

Classic“SR”

Remarks

The current Ready status can be read using this program message.
Possible replies:“NR”

The pressure is Not Ready within the limits defined by the control mode and current
control parameters.

“R ”

The pressure meets the ready criteria. The status is replied when the next pressure
measurement is finished.

“OL”

The pressure of one of the active Q-RPTs has exceeded the user defined upper or lower limits.

“OP”

The pressure of one of the Q-RPTs has exceeded the Q-RPT’s maximum limits.

“ER”

An internal device failure has occurred.

ExampleQuery sent:“SR?”(enhanced)

Query reply:“NR”

Example

Sent:

“SR”

(classic)

Reply:“NR”

See Also“PR”, “PRR”, “HS”, “SS”, “UL”, “LL” Commands
3.2.3, 3.2.21, 3.2.21.1

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PPC4™ OPERATION AND MAINTENANCE MANUAL

SS%
PurposeRead or set the current stability limit as a % of range.

Command“SS% n”

Query“SS%?”Classic“SS%=n”

Argumentsn:Remarks

The stability limit can be read and set as a percent of the full scale range of the Q-RPT range. If
this program message is used to set the stability limit, the PPC4 will then use CUSTOM control
settings.

ExampleCmd sent:“SS% .1”(enhanced)

Query reply:“0.10 %” (No reply from IEEE-488)

ExampleCmd sent:“SS%? .1”

(enhanced)

Query reply:“0.10 %”

ExampleSent:“SS%=.1”(classic)

Reply:“0.10 %”

Errors

ERR# 6

The argument was invalid.

See Also

“SS”

“SS%”
The stability limit in %FS of the current active range.

3.2.13SS
PurposeRead or set the current pressure stability limit.

Command“SS n”

Query

“SS?”

Classic“SS=n”

Arguments

N:

Remarks

The stability limit can be read and set as a pressure. The stability limit is used as theReady/Not Ready criterion in static control mode and when PPC4 not controlling.

ExampleCmd sent:“SS .1”(enhanced)

Query reply:“0.10 kPa/s”

ExampleCmd sent:“SS? .1”(enhanced)

Query reply:“0.10 kPa/s”

ExampleSent:“SS=.1”(classic)

Reply:“0.10 kPa/s”

Errors

ERR# 6

The argument was invalid.

See Also

“HS”

“SS”
The stability limit in the current pressure unit of measure.

3.2.13

Page 168(No reply from IEEE-488)

6. REMOTE OPERATION

STAT
PurposeRead the pressure control status.

Query“STAT?”Classic“STAT”

Remarks

The pressure control cycle status can be checked using this program message. The reply isa numeric code which references a specific pressure control action: Multiple codes are
returned by adding them them together.
0

The system is not generating or holding a pressure.

1

A new generation is preparing to start.

2

Quick ramping to the target.

4

Quick pulsing to the target.

8

Slow ramping to the target.

16

Slow pulsing to the target.

32

Reached the target, will re-adjust as needed to stay ready.

64

Quick ramping to a vent condition.

128

Executing a purge operation.

256

Quickly decreasing the pressure to reach a hard vacuum.

1024

A new target has been requested but generation has not started.

2048

PWM low pressure control

4096

Dynamic pulsing is being used to control a pressure.

8192

Static pulsing is being used to control a pressure.

16394

Low pressure pulsed control is active.

32768

Very low pressure pulsed control is active.

65536

Determining external volume

ExampleQuery sent:“STAT?”(enhanced)

Query reply:“32”

ExampleSent:“STAT”(classic)

Reply:“32”

See Also“PS“
3.2.2, 3.2.12

TIME
PurposeRead or set the PPC4 internal clock.

PurposeRead or set the PPC4 internal clock.

Command“TIME hh:mm:ssXX” or “TIME hh:mm:ss

Query“TIME?”Classic“TIME=hh:mm:ssXX” or “TIME=hh:mm:ss”“TIME”

Arguments

hh:mm:The time in a 12 hour format using a colon delimiter.

(12 hour mode)XX:”am” or “pm”

Arguments

hh:mm:The time in a 24 hour format using a colon delimiter(24 hour mode)
Remarks

The PPC4 has an internal real time clock. It is used for date stamping calibrations and log data.
The TIMEFMT command can be used to set the clock for 12hr or 24hr mode

ExampleCmd sent:“TIME 12:52PM”(enhanced 12hr)

Query reply:“12:52pm”

ExampleCmd sent:“TIME? 12:52PM”(enhanced 12hr)

Query reply:“12:52pm”

ExampleSent:“TIME=12:52PM”(classic 12hr)

Reply:“12:52pm”

ExampleSent:“TIME=18:22”(classic 24hr)

Reply:“18:22”Errors

ERR# 7:

Missing or improper program message argument(s).

See Also“TIMEFMT”, “DATE”
3.2.26.3

TIMEFMT
Page 169(No reply if IEEE-488)

PPC4™ OPERATION AND MAINTENANCE MANUAL

PurposeRead or set the clock time format.

Command“TIMEFMT n”

Query“TIMEFMT?”Classic“TIMEFMT=n”“TIMEFMT”

Argumentsn:‘0’ 12 hour format

Default“TIMEFMT 0”

Remarks

The real time clock can be set to report time in either a 12 hour or a 24 hour format.

ExampleCmd sent:“TIMEFMT 1”(enhanced)

Query reply:“1”

ExampleCmd sent:“TIMEFMT? 1”(enhanced)

Query reply:“1”

ExampleSent:“TIMEFMT=0”(classic)

Reply:“TIMEFMT=0”

Errors

ERR# 6

The argument was invalid.

‘1’ 24 hour format

See Also(No reply if IEEE-488)“TIME”
3.2.26.3

TP
PurposeTo read the current target pressure.

Query

“TP?”

Classic“TP”

Remarks

The current target pressure is replied in the current pressure unit of measure.

ExampleQuery sent:“TP?”(enhanced)

Query reply:“1000.00 kPa a”

Example

Sent:

“TP”

(classic)

Reply:“1000.00 kPa a”

See Also

“PS“
3.2.2

UCOEF
PurposeTo convert 1 Pascal to the current pressure units.

Query“UCOEF?”Classic“UCOEF”

Remarks

The PPC4 handles all pressure values internally in Pascal. The coefficient replied is equivalent of
1 Pa in the current pressure unit of measure. This program message allows the user to convert
pressures

ExampleQuery sent:“UCOEF?”(enhanced)

Query reply:“0.0010000000 kPa”

ExampleSent:“UCOEF”(classic)

Reply:“0.0010000000 kPa”

See Also

3.2.10, 9.2.1

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6. REMOTE OPERATION

UDUn
PurposeRead or set the user defined pressure units.

Command“UDUn label, ucoef”

Query“UDUn?”Classic“UDUn=label, ucoef”“UDUn”
label:

User unit label (5 alphanumeric char maximum). It cannot be an alreadysupported unit label.

ucoef:“User unit conversion coefficient (units/Pa).

Argumentsn:

The optional user defined unit to access (1 to 5). Assumes ‘1’ if not given.

Default“UDU USER,1.0”

Remarks

The user defined unit must be set up with this command prior to remote or local selection.
There are 5 separate user definable units. The GUI supports all 5 user defined user units,
while the basic version only has access to the first one (n = 1)

ExampleCmd Sent:“UDU MYUN, .001”(enhanced)

Query reply:“MYUN, 0.001000”

ExampleCmd Sent:“UDU? MYUN, .001”(enhanced)

Query reply:“MYUN, 0.001000”

ExampleSent:“UDU=MYUN, .001”(classic)

Reply:“MYUN, 0.001000”

ExampleSent:“UDU2=UN2, .01”

(classic)

Reply:“UN2, 0.010000”

See Also

3.2.10(No reply if IEEE-488)

UL
PurposeRead or set an upper limit for the current range.

Command“UL n”

Query

“UL?”

Classic“UL=n”“UL”

Argumentsn:Remarks

The PPC4 has an upper limit for each range and for each measurement mode (gauge andabsolute). New automated pressure control targets cannot be greater than this value. If thepressure does exceed the upper limit, the pressure display flashes, and pressure control stops.
Manual increases in pressure are not allowed as long as the pressure is above the upper limit.
Decreases in pressure are allowed. This feature should always be used to prevent accidental overpressure of a device under test.

The upper limit pressure in the current pressure unit and measurement mode.

ExampleCmd sent:“UL 1000”(enhanced)

Query reply:“1000.00 kPaa”

ExampleCmd sent:“UL? 1000”(enhanced)

Query reply:“1000.00 kPaa”

ExampleSent:“UL=1000”(classic)

Reply:“1000.00 kPaa”

Errors

ERR# 6:

The argument is out of range.

See Also“LL”
3.2.21Page 171(No reply if IEEE-488)

PPC4™ OPERATION AND MAINTENANCE MANUAL

UNIT
PurposeRead or set the pressure unit of measure unit and measurement mode.

Command“UNIT unit (, ref”)”“UNIT unitg (, ref”)”“UNIT unita (, ref”)”

Query“UNIT?”Classic“UNIT=unit (, ref”)”“UNIT=unitg (, ref”)”“UNIT=unita (, ref”)”“UNIT”

Arguments
Remarksunit:

The text corresponding to the pressure unit of measure.

ref:

The optional unit reference temperature only if the unit is “InWa”.

This program message determines what unit of measure and what measurement mode isused to display pressure values. Refer to Table 13 for a detailed list of the units available andtheir labels.
The unit text must be followed by ‘a’ if absolute measurement mode is desired, or gauge mode isassumed. The unit text can optionally be followed by a ‘g’ to specify gauge measurement
mode. There can be a space between the unit text and the ‘a’ or the ‘g’.
If a water column unit (inH2O, mH2O, mmH2O) is specified for the pressure unit of measure,
an optional second argument “ref” can be set. The “ref” can be 4, 20, or 60 corresponding to
InH2O at 4 °C, 20 °C or 60 °F. The reference temperature can also be added directly onto theend of the Unit argument or “@” plus the reference temperature if desired (“inH2O4”,“inH2O@4”, “inH2O20”, “inH2O@20”, “inH2O60”, or “inH2O@60 corresponding to inH2O at
4 °C, 20 °C or 60 °F). If a temperature reference is not specified, when the unit is “InH2O” or“mmH2O”, then the reference temperature is assumed to be 20 °C.

Note
The legacy units inWa, mWa and mmWa have been replaced by inH2O, mH2O
and mmH2O in the PPC4 and in documentation. The unit command andothers such as ARANGE continue to support the former “xxWA” units. The
conversion factors are identical.
The fifth character of the reply is always ‘a’ for absolute mode, or ‘g’ for gauge mode. White
spaces proceed this character if needed. The temperature reference is added to the reply
only if the unit is “InWa” or “mmWa”.
“MMODE” must be used to set the measurement mode to negative gauge. The “MODE”
command can also be used to set the desired measurement mode only.
ExampleCmd sent:“UNIT kPaa”(enhanced)

Query reply:“kPaa”

Sent:“UNIT InH2Og, 4”Query reply:“inH2Og, 4”

Sent:“UNIT InH2Og60”

Query reply:“inH2Og, 60”

Sent:“UNIT InH2O@20”

Query reply:“inH2Og, 20”

ExampleSent:“UNIT=kPaa”(classic)

Reply:“kPaa”

Sent:“UNIT=InH2Og, 4”

Reply:“inH2Og, 4”

Sent:“UNIT=InH2Og@20”

Reply:“inH2Og, 20”

ErrorsSee Also

ERR# 7:The unit is invalid.

ERR# 6:

The ref is invalid.

ERR# 20:

Absolute measurement mode and altitude units are not allowed with a gauge QRPT.

“MMODE”, “MODE”
3.2.10, 3.2.11

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6. REMOTE OPERATION

VAC
PurposeRead or set the status of the PPC4 EXHAUST port vacuum or atmosphere monitoring system.

Command“VAC n”

Query“VAC?”Classic“VAC=n”

Default“VAC 0”

Arguments

n:

“VAC”
’0’ To disable auto mode and specify that the PPC4 EXHAUST port is open
to atmosphere.
’1’ To disable auto mode and specify that the PPC4 EXHAUST port isconnected to a vacuum source.
NOTE: Use “AUTOVAC” to enable automated determination of EXHAUST
port conditions.
Remarks

The PPC4 has an internal sensor that determines if the EXHAUST port is open to atmosphereor to vacuum. You can manually override it if desired. The query can also be used to see thesensor status (if auto is enabled). If the auto function is disabled, then the query returns thelast VAC setting.

ExampleCmd sent:“VAC 1”(enhanced)

Query reply:“1”

ExampleCmd sent:“VAC? 1”(enhanced)

Query reply:“1”

ExampleSent:“VAC=1”(classic)

Query reply:“VAC=1”

Errors

ERR# 6:

The argument is not a ‘0’ or a ‘1’.

See Also“AUTOVAC”(No reply if IEEE-488)

3.2.27.2
VENT
PurposeRead, execute or abort a vent process.

Command“VENT n”

Query

“VENT?”Classic“VENT=n”“VENT”

Arguments

N:’1’ to start a vent process.
’0’ to abort a vent process and close the exhaust valve.

Remarks

The PPC4 vents by setting pressure close to atmospheric and then opening the vent valve.
This program message query returns a ‘0’ if the vent valve is closed, or a ‘1’ if the vent valve
is open.
In gauge measurement modes, a “PS” command of zero is interpreted as a vent command.

ExampleCmd sent:“VENT 1”(enhanced)

Query reply:“0” (if not finished venting) (No reply if IEEE-488)

ExampleCmd sent:“VENT? 1”(enhanced)

Query reply:“0” (if not finished venting)

ExampleSent:“VENT=1”(classic)

Reply:“VENT=0” (if not finished venting)Errors

ERR# 6:

See Also“PS”“1” (if vented)“1” (if vented)“VENT=1” (if vented)
The argument is not a ‘0’ or a ‘1’.

3.2.1, 3.2.14

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PPC4™ OPERATION AND MAINTENANCE MANUAL

VER
PurposeIdentify the PPC4, US or SI units, the Q-RPT labels and the software version.

Query“VER?”Classic“VER”

Remarks

The software version of the PPC4 can be read. This is useful for checking for the presence of
the PPC4 and for reference purposes. It indicates the internal Q-RPT(s) and software version.

ExampleQuery sent:“VER?”(enhanced)

Query reply:“DH INSTRUMENTS, INC PPC4 us A350K/BG15K Ver1.00 ”

ExampleQuery sent:“VER”(classic)

Query reply:“DH INSTRUMENTS, INC PPC4 us A350K/BG15K Ver1.00 ”

See Also

None

ZOFFSETn
PurposeRead or set the AutoZ pressure offsets (Poffset) for the specified or active RPT (preferred
method).

Command“ZOFFSETn GaOffset , AbsOffset”

Query“ZOFFSETn?”Classic“ZOFFSETn =GaOffset , AbsOffset”“ZOFFSETn”

Defaults“ZOFFSETn = 0.0 Pa, 0.0 Pa”(Gauge Q-RPT)“ZOFFSETn = 101325 Pa, 0.0 Pa” (Absolute Q-RPT)
Optional Suffix“n”

The active RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT.
‘2’ Specify the Lo Q-RPT

Arguments
Remarks

GaOffset

The RPT pressure offset (“Poffset”) for Gauge measurement mode (Pa).

AbsOffset:

The RPT pressure offset for absolute measurement mode (Pa)The pressure offset (Poffset) for the specified internal RPT (IH or IL) or the active Q-RPT can beaccessed with this program message. There is a separate offset for gauge and absolutemeasurement modes, but not all modes apply in all cases. (Gauge RPTs do not support“AbsOffset).

 Caution•

Using this program message overwrites the current offset.

•

Changes made using this program message take effect immediately. If no
suffix is given and the active RPT is in an external RPM4, then the Poffset forthat RPM4’s Q-RPT will be accessed.

ExampleCmd sent:“ZOFFSET1 2.1, 0”(enhanced)

Query reply:“

ExampleSent:“ZOFFSET=97293.1, 3.02”(classic)

Reply:“

Errors

ERR# 6:

One of the arguments is out of range.

See Also

3.2.222.10 Pa, 0.00 Pa”
97293.10, 3.02”

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6. REMOTE OPERATIONZOFFSET:IH and ZOFFSET:IL
PurposeCommand

Read or set the AutoZ pressure offset (Poffset) for the high (“IH”) or low (“IL”) Q-RPT andcurrent measurement mode. New designs should use the “ZOFFSETn” command.
“ZOFFSET:IH offset”“ZOFFSET:IL offset”

Query“ZOFFSET:IH?”“ZOFFSET:IL?”

Classic“ZOFFSET:IH =offset”“ZOFFSET:IL =offset”“ZOFFSET:IH”“ZOFFSET:IL”

Defaults“ZOFFSET:IH = 0.0”
“ZOFFSET:IL = 0.0”

6.6

Arguments

Offset:The Q-RPT pressure offset (“Poffset”) for the current measurement mode
(gauge or absolute) in Pa.

Remarks

The pressure offset (Poffset) for the specified Q-RPT (Hi or Lo) in the current measurementmode can be accessed with this program message. External Q-RPTs’ Poffset cannot be adjusted
from PPC4. There is a separate offset for gauge and absolute measurement modes. Using
this program message will overwrite the current offset, so caution must be used. Changes
made using this program message take effect immediately.

ExampleCmd sent:“ZOFFSET:IL 2.1”

(enhanced)

Query reply:“

ExampleSent:“ZOFFSET:IL=2.1”(classic)

Reply:“

Errors

ERR# 6:

One of the arguments is out of range.

See Also

3.2.222.10 Pa”
2.10 Pa”

Status Reporting System

The PPC4 status reporting system is used to track and report system status and errors. It follows themodel of the IEEE Std 488.2 and works for the COM1 and the IEEE-488 port with slight differences.
The PPC4 can be programmed to respond to various status conditions by asserting the SRQ of the IEEE488 interface. The COM1 port cannot be supported in such a way, so polling must be used.

6.6.1

Error Queue

The PPC4 keeps track of remote errors by using an error queue. If an error occurs, it is pushed
onto the Error Queue. If you are using the COM1 port, the error number is immediately
replied in the form “ERR#nn where nn is the error code from 0 to 99. The “ERR?” (or “ERR”)
query can then be used to pull the error from the Error Queue in it’s descriptive text format.
If you are using the enhanced program message format, the Error Queue will accumulate
errors until full unless they are pulled from the queue. If you are using the classic program
format, the Error Queue is cleared every time a new program message is received.

6.6.2

Status Byte Register

The PPC4 contains an 8 bit Status Byte Register that reflects the general status of the PPC4.
Table 23. 8 Bit Status Byte Register
OPER
(128)

RQS/MSS
(64)

ESB
(32)

MAV
(16)

N/A
(8)

ERROR
(4)

N/A
(2)

RSR
(1)

This register is affected by the PPC4 reply output queue, the Error Queue, the Standard
Event Status register and the Ready Event Status register.

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PPC4™ OPERATION AND MAINTENANCE MANUAL

Status Byte Register(“∗STB?” or ”∗SRE n”)
OPER
(128)
Standard Event Status Register(“∗ESR?” or “∗ESE n”)

RQS/MSS
(64)
ESB
(32)

←←←

PON
(128)

URQ
(64)

MAV
(16)

←←←

OUTPUT
QUEUE

←←←

ERROR
QUEUE

CMD
(32)

EXE
(16)

DDE
(8)

QYE
(4)

RQC
(2)

OPC
(1)

MEAS
(4)

NRDY
(2)

RDY
(1)

N/A
(8)
ERROR
(4)

Ready Event Status Register(“RSR?” or ” RSE n”)

N/A
(2)
RSR
(1)

←←←

N/A
(128)

N/A
(64)

N/A
(32)

N/A
(16)

N/A
(8)

Figure 28. Status Register Schematic

The Status Byte Register can be read using the “*STB?” query, or by performing a serial pollon the IEEE-488 bus. If you read this using a serial poll then Bit 6 is the RQS. If the“*STB?” query is used, then bit 6 is the MSS bit. All of the other bits are common to both typesof query.
Each of these status bits can cause a SRQ to occur. The Service Request Enable Register(“*SRE” program message ) determines which of these flags are able to assert the SRQ line.
This enable register has a matching set of bits that each will enable the designated bit tocause a SRQ, except for the RQS/MSS bit(s) which cannot cause a SRQ. If you set thisregister to 20 ($14 hex), an SRQ will occur if the MAV or the ERROR bit are set.
The description of these bits are given as:
OPER

N/A Bit 7 (128)

RQS

Requested Service Bit 6 (64)
Indicates that the SRQ line of the IEEE-488 interface has been asserted by the
PPC4. This bit is cleared when a serial poll is performed on the PPC4, and is apart of the Status Byte Register when read using a serial poll. This bit does not
apply if the COM1 port is being used.

MSS

Master Summary Status Bit 6 (64)
Indicates that an event or events occurred that caused the PPC4 to request service
from the Host, much like the RQS bit. Unlike the RQS bit, it is READ ONLY and canbe only cleared when the event(s) that caused the service request are cleared.

ESB

Event Summary Bit 5 (32)
Indicates if an enabled bit in the Standard Event Status Register became set(see Section 4.5.3).

MAV

Message Available Bit 4 (16)
Indicates that at least one reply message is waiting in the PPC4 IEEE-488 output
queue.

ERROR

Error Queue Not Empty Bit 2 (4)Indicates that at least one command error message is waiting in the PPC4 IEEE-488
error message queue. Use the “ERR?” query to get this message.

RSR

Ready Summary Bit 0 (1)Indicates that an enabled bit in the Ready Status Register became set.
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6. REMOTE OPERATION

6.6.3

Standard Event Register

The PPC4 contains an 8 bit Standard event register that reflects specific PPC4 events.
Enabled events in this register will set or clear the ESB bit of the Status Byte Register.
Table 24. 8 Bit Standard Event Register
PON

URQ

CMD

EXE

DDE

QYE

RQC

OPC

(128)

(64)

(32)

(16)

(8)

(4)

(2)

(1)

This register can be read using the “*ESR?” query, Each of these status bits can set the ESB
bit of the Status Byte Register, causing a SRQ to occur IF the ESB bit is enabled to do so.
The Standard Event Status Enable Register (“*ESE” program message ) determines which ofthese flags are able to assert the ESB bit. The description of these bits are given as:
PONPower On (Bit 7)
Indicates that the PPC4 power has been cycled since the last time this bit wasread or cleared.

URQ

User Request (Bit 6)
Indicates that the PPC4 was set to local operation manually from the front panelby the user (pressing the [ESC] key).

CMD

Command Error (Bit 5)
Indicates that a remote command error has occurred. A command error istypically a syntax error in the use of a correct program message.

EXE

Execution Error (Bit 4)
Indicates if a remote program message cannot be processed due to device
related condition.

DDE

Device Dependent Error (Bit 3)
Indicates that an internal error has occurred in the PPC4 such as a transducer
time-out.

QYE

Query Error (Bit 2)
Indicates that an error has occurred in the protocol for program message
communications. This is typically caused by a program message being sent to
the PPC4 without reading a waiting reply.

RQC

Request Control (Bit 1)
This bit is not supported as the PPC4 cannot become the active controller in charge.

OPC

Operation Complete (Bit 0)
Indicates that the PPC4 has completed all requested functions.

6.6.4

Ready Status Register

The PPC4 contains an 8 bit Ready Status Register that reflects specific PPC4 measurement
and generation ready events (see Section 3.2.3). Enabled events in this register will set or
clear the RSB bit of the Status Byte Register.
Table 25. 8 Bit Ready Status Register
N/A

N/A

N/A

N/A

N/A

MEAS

NRDY

RDY

(128)

(64)

(32)

(16)

(8)

(4)

(2)

(1)

This register can be read using the “*RSR?” query, Each of these status bits can set the
RSB bit of the Status Byte Register, causing a SRQ to occur IF the RSB bit is enabled to do so.
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PPC4™ OPERATION AND MAINTENANCE MANUALThe Standard Event Status Enable Register (“*RSE” program message ) determines whichof these flags are able to assert the RSB bit. The description of these bits are given as:
MEAS

Measurement ready (Bit 2)
Indicates that the PPC4 has completed a Q-RPT measurement.

NRDY

Generation Not Ready (Bit 1)
Indicates that the PPC4 made a transition from Ready to Not Ready as definedby the control settings (see Section 3.2.2).

RDY

Generation Ready (Bit 0)
Indicates that the PPC4 has reached a target pressure and is Ready as definedby the control settings (see Section 3.2.2).

6.7

IEEE STD. 488.2 Common And Status Program
Messages

The PPC4 supports a set of commands that are common to all instruments conforming to IEEE Std. 488.2.
These command make it easy to perform basic function for any device that supports these commands.
These commands also cover the status reporting commands. See Section 4.5 for details on the status
registers mentioned in these commands.
Table 26. Program Message List
∗CLS

Clear all of the status & event structures.

∗ESE

Read or set the Standard Event Status Enable Register.

∗ESR

Read the Standard Event Status Register.

∗IDN

Identify the PPC4 version, range, and serial number.

∗OPC

Set the operation complete bit when all operations have completed.

∗OPT

Read the list of installed PPC4 options.

∗RST

Reset the PPC4 control settings to factory settings.

∗TST

Read the power on self test status.

∗SRE

Read or set the Service Request Enable Register.

∗STB

Read the Status Byte Register.

∗RSE

Read or set the Ready Status Enable Register.

∗RSR

Read the Ready Status Register.

6.7.1

Program Message Descriptions∗CLS
PurposeClear all of the status & event structures.

Command“∗CLS”

Remarks

This program message clears the following events and status registers:
Standard Byte Register (STB)
Standard Event Status Register (ESR)
Error Queue
Pending OPC operations

ExampleSent:“∗CLS”(classic)

Reply:

none

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6. REMOTE OPERATION∗ESE
PurposeRead or set the Standard Event Status Enable Register.

Command“∗ESE n”

Query“∗ESE?”

Default“∗ESE 0”

Argumentsn:Remarks

The Standard Event Status Enable register determines which bits in the standard Event
Status Register are enabled and included in the Status Byte Register (ESB bit), and canassert the SRQ line. The reply is in decimal numeric form.

ExampleSent:“∗ESE=128” (enables the PON bit)(enhanced)

Query reply:“128” (no reply if IEEE-488)

Errors

ERR# 6:n is not valid.

’0 to 255’ This is the decimal representation of the bit(s) to enable. To enable
the PON and QYE bits, the argument would be 128 + 4 = 132.

∗ESR
PurposeRead the Standard Event Register.

Command“∗ESR?”

Remarks

The Standard Event Register contents are cleared after reading. The reply is in decimal numericform.

ExampleSent:“∗ESR?”(enhanced)

Reply:“20” (the QYE and EXE bits are set)

∗IDN
PurposeQuery

Identify the PPC4 versions, range, and serial number.

Remarks

Example(enhanced)“∗IDN?”The identification reply is made up of the following comma delimit fields:
Manufacturer
The product model
Serial number of the PPC4
Serial number of the HI pressure RPT
Serial number of the LO pressure RPT (‘0’ if not installed)
PPC4 software version.
CPU board logic version
Main board logic version.
Sent:“∗IDN?”
Reply:“DH INSTRUMENTS INC, PPC4, 123,100951,63041, Ver1.00E, 1.00a,1.00a”∗OPC
PurposeSets the operation complete bit when all operations have completed.

Command“∗OPC”

Query“∗OPC?”

Remarks

This Command enables the PPC4 to set the OPC bit in the Standard Event Status Registerwhen it has completed all pending functions.
The Query replies with a “1” when all functions are complete.

ExampleSent:“∗OPC”(enhanced)

Query reply:

“1”

∗OPT
PurposeQuery
Remarks

Example(enhanced)

Reads the list of installed PPC4 options.
“∗OPT?”
This Query returns any registered option(s) installed in the PPC4. Each option is separated
by a comma. If there are no options installed, the reply will be “NONE”
Possible options:“IEEE-488:0”
The IEEE-488 option is installed.
“USB”
The rear panel USB port is installed“ETHERNET”
The rear panel Ethernet option is installed“GUI”
Indicates PPC4-gui with an LCD
Sent:“∗OPT?”
Reply:“IEEE-488:0, USB, ETHERNET”
Reply:“NONE”(no options installed)

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PPC4™ OPERATION AND MAINTENANCE MANUAL∗RST
PurposeResets the PPC4 control settings to factory settings.

Command“∗RST””

Remarks

This Command sets the PPC4 settings to factory settings. This equivalent to a front panel
executed RESET/SET. This does not affect the communications settings.

ExampleSent:“∗RST”(enhanced)

Reply:“∗RST” (no reply if IEEE-488)

See Also

Section 3.5.4.1, Reset - Sets

∗SRE
PurposeRead or set the Service Request Enable Register.

Command“∗SRE n”

Query“∗SRE?”

Default“∗SRE 0”

Argumentsn:Remarks

The Service Request Enable Register determines which bits of the Status Byte can set the MSS
bit of the Status Byte and request service by asserting the SRQ line of the IEEE-488 interface.

ExampleSent:“∗SRE=48” (enables the MAV and ESB bits)(enhanced)

Query reply:“48” (no reply if IEEE-488)

Errors

ERR# 6:n is not valid.

’0 to 255’ This is the decimal representation of the bit(s) to enable. To allow theMAV and ESB bits to assert the SRQ line, the argument would be 32 + 16 = 48.
Bit 6 (64) is reserved and cannot be set.

∗STB
PurposeRead the Status Byte Register.

Command“∗STB?”

Remarks

The Status Byte Register reflects the general status of the PPC4. The ‘MSS’ bit state isrepresented by bit 6.

ExampleSent:“∗STB?”(enhanced)

Reply:“80” (The MSS and MAV bits are set)

∗TST
PurposeRead the power on self test status.

Query“∗TST?””

Remarks

The PPC4 system memory stores the user settings (units, resolution, generation settings)
and retains them when the unit if OFF. On power-up, this memory is checked. If this memory
is corrupted, all user settings are reset to default (as if the “∗RST” program message was
executed), and the ∗TST query will return a non zero value. If the PPC4 passed the test on
power-up OR if the ∗TST query was used at least once since the PPC4 was powered up the
reply will be a ‘0’.

ExampleSent:“∗RST?”(enhanced)

Reply:“1”*RSE
PurposeRead or set the Ready Status Enable Register.

Command“RSE n”

Query“RSE?”

Default“RSE 0”

Argumentsn:Remarks

The Ready Status Enable Register determines which bits in the Ready Status Register are
enabled and included in the Status Byte Register (RSR bit), and can assert the SRQ line. The
reply is in decimal numeric form.

ExampleSent:“∗RSE=1” (enables the RDY bit)(enhanced)

Query reply:“1” (no reply if IEEE-488)

Errors

ERR# 6:n is not valid.

’0 to 255’ This is the decimal representation of the bit(s) to enable. To enable
the RDY bit, the argument would be 1.

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6. REMOTE OPERATION*RSR
PurposeRead the Ready Status Register.

Command“RSR?”

Remarks

The Ready Status Register contents are cleared after reading. The reply is in decimal numericform.

ExampleSent:“RSR?”(enhanced)

Reply:“6” (The MEAS and NRDY)

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Notes:

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7.

Maintenance, Adjustments andCalibration

7.1

Overview

PPC4 was designed for maintenance free operation. No maintenance is required other than:•

Regular rezeroing of quartz reference pressure transducers (Q-RPT), if present (see 3.2.22).

•

Periodic calibration of Q-RPTs, if present (see Section 7.2).

•

Adjustment of the on-board barometer and/or utility sensor, if present (see Sections 7.3, 7.4).

•

Automated adjustment of pressure controlling parameters, as needed (see Section 3.2.13).

This section provides information on maintenance, adjustment and calibration procedures, and recommended
overhaul procedures.

 Caution
PPC4 is a sophisticated pressure setting and measuring instrument with advanced
on-board features and functions. Before assuming that unexpected behavior iscaused by a system defect or breakdown, use this manual and other training
facilities to become thoroughly familiar with PPC4 operation. For rapid assistancein specific situations use the troubleshooting guide in Section 8.

Note
PPC4 is covered by a limited one (1) year warranty. Unauthorized service or repair
during the warranty period is undertaken at the owner’s risk and may cause
damage that is not covered under warranty and/or may void the warranty.

7.2

Calibration of Quartz Reference Pressure
Transducers (Q-RPTs)
7.2.1

Principle

PPC4 may be equipped with one or two quartz reference pressure transducers (Q-RPTs)
that are the source of low uncertainty pressure measurement for the system.
To calibrate a Q-RPT, pressures from a reference are applied to the Q-RPT at ascending anddescending points over the range. The recommended pressure sequence for a calibration varies
depending on whether the Q-RPT is of Premium, Standard or Full Scale Standard class (seeSection 1.2.2.1). The pressure defined by the reference and the corresponding Q-RPT readings
are recorded at each point. After all of the pressures have been applied and recorded,adjustments are made to fit the Q-RPT pressure readings to the reference. Fitting the readings
means performing a linear regression to arrive at the lowest value of the residuals of errors of the
Q-RPT relative to the reference. The Q-RPT output is adjusted by user settable coefficients: PA(an adder or offset) and PM (a multiplier or span adjustment) (see Section 7.2.1.1).
The calibration process is performed independently on each Q-RPT to arrive at its optimal fit.

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When running calibrations, collecting as received data and calculating PA and PM
adjustments, whether AutoZ is normally used, whether it is ON or OFF and what the value ofZoffset is should be considered (Section 3.2.22).

Note
CalTool for RPTs software provided with the PPC4 supports thecalibration process of PPC4 Q-RPTs. CalTool and its documentation areprovided on a General Accessories Disk with the new PPC4. Most users
should use CalTool software to assist in the calibration of PPC4.
PPC4 is delivered with an interactive Q-RPT calibration utility that steps the operator throughthe complete Q-RPT calibration procedure including applying the necessary pressures,
collecting data automatically, calculating new PA and PM values, previewing the results of
the new calibration and activating the results of the new calibration (see the CalTool for RPTs
manual on the General Accessories Disk). PPC4 also provides complete front panel andremote access to Q-RPT calibration parameters so that Q-RPT calibrations can be performed
without using CalTool software (see Section 7.2.8).

Note
PPC4 may also use external Q-RPTs mounted in RPM4 Reference
Pressure Monitors. RPM4 Q-RPTs are calibrated independently of PPC4
(see the RPM4 Operation and Maintenance Manual).

7.2.1.1

PA and PM Coefficients

The coefficients used to adjust Q-RPT readings are designated PA (an adder oroffset) and PM (a multiplier or span set). The coefficients affect the Q-RPT
reading following:
Corrected reading = (Uncorrected reading • PM) + PA
PA is expressed in units of pressure (always the SI unit, Pascal).
PM is dimensionless.
Each Q-RPT has its own unique PA and PM values. The PA and PM values
currently in use can be viewed and edited in the CAL function (see Section
6.5.4). PA and PM values are automatically edited when CalTool software isused and the results are activated.

 Caution
As editing PA and PM values will change Q-RPT calibration,
they should only be edited by qualified personnel as part of thecalibration process.
Caution should be taken to avoid
accidental editing and a security system is available to prevent
access (see Section 3.2.26.5). Incorrect editing of PA and PM
values can cause out of tolerance measurements.

Note
A new PPC4 is delivered with PA and PM values set to zero and
1 for all Q-RPTs. This does not mean that the PPC4 has not beencalibrated. In the original factory calibration, privileged factorycoefficients are used for calibration with the user PA and PM
set to zero and 1.

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7.2.1.2

As Received and As Left Data

Frequently, calibration procedures require that as received and as left data bereported. The necessary information to report as received and as left data on thecalibration of PPC4 Q-RPTs can be obtained in several ways.
When the PPC4 CalTool calibration assistance software is used, as received
data is displayed while running the calibration and is automatically recorded andprovided if desired. As left data is also calculated and presented.
At any time, a) reference pressures applied, b) associated transducer readings,c) PA and PM and Poffset values can be used to calculate as received and as left
values. For example, backing out PA and PM on the as left data yields thetransducer readings with PA = 0 and PM = 1. Then applying the as received PA
and PM and Poffset values to the readings calculates as received readings(the readings that the transducer would have made with the old PA, PM and Poffset).
•

It is recommended that “as received” values of PA, PM andPoffset (for absolute mode calibrations if if AutoZero is usedin normal operation) be recorded for each Q-RPT prior torunning the calibration.

7.2.1.2.1

Basic Interface

The current PA and PM and absolute mode Poffset can be viewed by using<Spec>, <Cal>, <Hi RPT/Lo RPT/Barometer>, <View> from the Main Menu.
The current value of gauge mode Poffset can be viewed by using <Spec>,<AutoZ>, <View> from the Main Menu.

7.2.1.2.2

Advanced Interface

The current PA, PM and Poffset values can be viewed by using [Settings],<More >>>, <Calibration>. From this screen either the Hi RPT, Lo RPT or
Barometer may be viewed.
For both Hi and Lo RPT, using <Calibration> displays Cal Date, PA and PM. For
Hi and Lo RPT, using <AutoZ> diaplays the values for Gauge Poffset and, if the
Q-RPT is absolute, Absolute Poffset as well.
Using Barometer shows the Barometer screen, displaying Cal Date, PA , PM
and the current Barometer reading.

Note
If the security level is set to Low or High viewing the calibration
coefficients is allowed but no changes are accepted. A warning
is displayed when entering and exiting secure screens.

7.2.2

Equipment Required
Note
The recommended calibration standards for PPC4 Q-RPTs are DHI
PG7000 gas operated piston gauges (PG7201, PG7202, PG7601). Contact
DHI for additional information.

Gas operated piston gauge (deadweight tester), with the following characteristics:•

Measurement uncertainty of ± 0.0025 % of reading for Standard or Full Scale
Standard Class Q-RPTs or ± 0.002 % of reading for Premium Class Q-RPTs. A
reference with greater measurement uncertainty may be used but PPC4 measurement
uncertainty may be degraded proportionally from published specifications.
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If the Q-RPT is an Axxx (absolute) type and will be used in the absolute and/or
negative gauge measurement modes, the reference must be able to apply absolutepressures: Absolute pressures may be achieved either by operation relative to an
evacuated bell jar or, for higher pressures, by addition of atmospheric pressure
measured by a high accuracy barometer. Axxx (absolute) Q-RPTs that will not be
used in absolute of negative gauge measurement modes (as is very often the casefor higher pressure Q-RPTs) do not require the application of absolute pressure forcalibration and may be calibrated using a gauge pressure reference.

 Caution
Axxx (absolute) Q-RPTs calibrated in gauge measurement mode by
applying gauge reference pressure values should be used in gauge mode
only (see Sections 3.2.11, 7.2.5).
•

Able to supply the recommended sequence of pressure points in the range tobe calibrated: See Section 7.2.4 for information on the recommended calibration point
sequence for various Q-RPT types and classes.

7.2.3

Set-up and Preparation

To set-up and prepare the PPC4 for calibration of an internal Q-RPT:
Set the PPC4 on a stable surface near the calibration standard at a height as close as
possible to the calibration standard’s reference height. Consider the connections that
may need to be made to the rear panel and access to the front panel display and keypad.
Connect a pressure supply greater than the maximum pressure to be applied during thecalibration to the PPC4 rear panel SUPPLY port (1/8 in. NPT F). (See Section 2.3.4)
If the calibration will include pressures under atmospheric pressure, connect a vacuum
pump to the PPC4 rear panel EXHAUST port (1/4 in. NPT F). There will be a constant
bleed of gas through the EXHAUST port so the vacuum pump should be self-venting or
disconnected when OFF (see Section 2.3.5).
Connect the calibration standard output to the PPC4 rear panel TEST(+) port (1/8 in. NPT F).

 Caution
DO NOT apply pressure to the TEST(+) port without having a pressure
supply greater than the applied pressure connected to the SUPPLY port.
Do not cause sudden external pressure changes. Damage to internal
PPC4 components could result. Unless the piston gauge used to calibrate
the PPC4 has automated pressure control, it is highly recommended that
the PPC4 direct pressure control keys (see Section 3.2.1) be used to slew
and adjust pressure during the calibration. This will minimize the risk ofaccidental overpressure of the PPC4 Q-RPTs.

7.2.4

Recommended Calibration Point Sequence

Calibration adjustments to PPC4 Q-RPTs are made by adjusting calibration coefficients,
PA and PM (see Section 7.2.1.1). To adjust these coefficients to optimum values giving thebest results over the Q-RPTs complete operating range, specific calibration point sequences
are recommended. The recommended point sequence depends upon whether the Q-RPT
being calibrated is a Premium, Standard or Full Scale Standard Class (see Section 1.2.2.1).
The class of the PPC4 Q-RPTs is indicated on the model number on the product label and on
the rear panel Q-RPT model (<p> for premium, 
 for standard and <f> for full scale
standard - for example A7Ms or A7Mp).
Prior to running the calibration point sequence, the Q-RPT should be exercised by:a) Setting full scale pressure.
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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATIONb) Dwelling at full scale pressure for 5 minutes.
c) Returning to atmospheric pressure (vented). If the Q-RPT is a gas operated Axxx type,use vacuum rather than atmospheric pressure.
d) Dwelling for twenty minutes.
A dwell time after setting the pressure of at least 60 seconds before taking data at each pointis recommended.
Section 7.2.4.1 gives calibration point sequences for Standard and Full Scale Standard Class
Q-RPTs and Section 7.2.4.2 gives calibration point sequences for Premium Q-RPTs.

Note
It is not required that the calibration pressure standard apply precisely thenominal pressure value of each calibration point as long as the exact
value of the applied pressure is known. Best results are obtained if theactual applied pressure is within 2 % of the nominal point definition.

7.2.4.1

Standard and Full Scale Standard Class Q-RPTs

See additional information in Section 7.2.4 concerning exercising the Q-RPT anddwell time at pressure points.
Table 27. Calibration Point Sequence, Standard Class, Axxx and Gxxx Q-RPTs
CALIBRATIONSEGMENT

Ascending

Descending

1

POINT
NO.
1
2
3
4
5
6
7
8
9

POINT
[% OF SPAN]
1
Lowest Pressure
25 %
50 %
75 %
100 %
75 %
50 %
25 %
1
Lowest Pressure

In absolute mode, the lowest point that can be set reliably by
the reference piston gauge. Zero (vented) in gauge mode.

Note
Axxx (absolute) Q-RPTs that will NOT be used in absolute or
negative gauge measurement modes may be calibrated ingauge measurement mode with a gauge pressure standard.
Axxx (absolute) Q-RPTs calibrated in gauge measurementmode by applying gauge reference pressure values should be
used in gauge mode only (see Section 7.2.5).

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Table 28. Calibration Point Sequence, Standard Class, BGxxx Q-RPTs
CALIBRATIONSEGMENT

Ascending

Descending

1.

POINT
NO.
1
2
3
4
5
6
7
8
9

POINT
1
[% OF SPAN]
0%
25 %
50 %
75 %
100 %
75 %
50 %
25 %
0%

The BG15K span is – 15 to + 15 kPa, 30 kPa total. Therefore,
0 % is – 15 kPa, 25 % is – 7.5 kPa, 100 % is + 15 kPa, etc.

Note
BGxxx (bi-directional gauge) Q-RPTs that will NOT be used innegative gauge measurement mode may be calibrated in gauge(positive pressures) measurement mode only. Use the gauge
mode (Gxxx) calibration point sequence (see Table 27). BGxxx
Q-RPTs calibrated in gauge measurement mode only should not
be used in negative gauge mode.
Table 29. Calibration Point Sequence, Standard Class, BA100K Q-RPTCALIBRATIONSEGMENT

Ascending

Descending

POINT
NO.
1
2
3
4
5
6
7
8
9

POINT
1
[% OF SPAN]
0%
25 %
50 %
75 %
100 %
75 %
50 %
25 %
0%

1. The BA100K span is 70 to 110 kPa absolute.

7.2.4.2

Premium Class Q-RPTs

See additional information in Section 7.2.4 concerning exercising the Q-RPT anddwell time at pressure points.
Verification of Premium Class Q-RPTs
When verifying (as opposed to calibrating) a Premium Q-RPT it is not necessary toinclude the higher density of points that is recommended for determination of thecalibration coefficients. A standard ascending/descending 9 or 11 point run isadequate. To verify that the uncertainty turndown with AutoRange is in tolerance(see Sections 3.2.6, 1.2.2.1), it is recommended that the verification of a Premium
Q-RPT include a verification of an AutoRanged span of 30 % of the maximum QRPT span. For example, verify an A7M Q-RPT in the default range of 0 to 7 MPa (1000 psi) and in the AutoRange range of 2.1 MPa (300 psi).

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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATION

Table 30. Calibration Point Sequence, Premium Class, Axxx and Gxxx Q-RPTs
CALIBRATIONSEGMENT

Ascending

Descending

1

POINT
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

POINT
[% OF SPAN]
1
Lowest Pressure
5%
10 %
15 %
20 %
30 %
40 %
50 %
60 %
80 %
100 %
80 %
50 %
20 %
1
Lowest Pressure

In absolute mode, lowest point that can be set reliably by thereference piston gauge. Zero (vented) in gauge mode.

Note
Axxx (absolute) Q-RPTs that will NOT be used in absolute or
negative gauge measurement modes may be calibrated ingauge measurement mode with a gauge pressure standard.
Axxx (absolute) Q-RPTs calibrated in gauge measurement mode
by applying gauge reference pressure values should be used ingauge mode only (see Section 7.2.5).
Table 31. Calibration Point Sequence, Premium Class, BGxxx Q-RPTs
CALIBRATIONSEGMENT

Ascending

Descending

1.

POINT
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

POINT
1
[% OF SPAN]
0%
15 %
30 %
40 %
45 %
50 %
55 %
60 %
70 %
85 %
100 %
70 %
50 %
30 %
0%

The BG15K span is – 15 to + 15 kPa, 30 kPa total. Therefore,
0 % is – 15 kPa, 25 % is – 7.5 kPa, 100 % is + 15 kPa, etc.

Note
BGxxx (bi-directional gauge) Q-RPTs that will not be used innegative gauge measurement mode may be calibrated in gauge(positive pressures) measurement mode only. Use the gauge
mode (Gxxx) calibration point sequence (see Table 30). BGxxx
Q-RPTs calibrated in gauge measurement mode only should not
be used in negative gauge mode.

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7.2.5

Turning Off Absolute and Negative Gauge
Measurement Modes for Axxx (Absolute) Q-RPTs

 PURPOSE
To prevent operation in absolute and negative gauge measurement modes with an Axxx
(absolute) Q-RPT.
 PRINCIPLE
Axxx (absolute) Q-RPTs are frequently used in gauge measurement mode only (see Section
3.2.11). Axxx Q-RPTs that are used in gauge mode only, may be calibrated in gauge modewith a reference that applies gauge pressures. Calibration with an absolute reference is notnecessary. However, if an Axxx Q-RPT is calibrated in gauge mode, it is not possible toknow if it is in or out of tolerance in absolute and negative gauge modes. To avoid using
absolute and negative gauge measurement modes on an Axxx Q-RPT that is calibrated forgauge mode only, access to absolute and negative gauge modes can be turned ON and OFF.
 OPERATION

Note
See Section 7.2.7 for more detailed information on editing and viewing
Q-RPT calibration information.

 Caution
As editing PA and PM values will change the calibration of the Q-RPTs,
the edit function should only be used by qualified personnel as part of thecalibration process. Caution should be taken to avoid accidental editing.
A user level security system is available to control access (see Section
3.2.26.5).

7.2.5.1

Basic Interface

Turning absolute and negative gauge mode operation ON and OFF for a Q-RPT
occurs in the same area in which calibration coefficients is edited. To access the
Q-RPT calibration editing area use <Spec>, <Cal> and select the desired QRPT. Then <Edit> to make changes.
 through the calibration information.
After viewing the values of PA and PM thedisplay is:

Absolute andneg g mode: ♦Off ♦On

The cursor is on the number corresponding to the current selection. Make thedesired selection. <On> causes absolute and negative gauge modes to be
unavailable for the Q-RPT.

7.2.5.2

Advanced Interface

The Gauge Only setting is located in the [Settings], <More >>>, <Calibration>,<Hi RPT> or <Lo RPT>, <Calibration> screen. If security is Off (see Section
3.2.26.5) Gauge only can be changed. Setting Gauge Only to On causes
absolute and negative gauge modes to be unavailable for the Q-RPT.
[OK] to accept change and exit to Main Run Screen, [Back] to retun to<Calibration> without making changes, [Esc] or  to exit to the Main Run
Screen without making changes.

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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATION

Note
PPC4 may also use external Q-RPTs mounted in RPM4 Reference
Pressure Monitors. Viewing and adjustment of RPM4 calibration
information is performed locally on the RPM4, not through PPC4
(see the RPM4 Operation and Maintenance Manual).

7.2.6

Q-RPT Calibration Using CalTool for RPTs Software

To calibrate PPC4 Q-RPTs using CalTool software, refer to Sections 7.2.1, 7.2.2 and 7.2.3 inthis manual and then refer to the CalTool for RPTs Software Manual.
CalTool for RPTs software and manual are supplied on the PPC4 General Accessories Disk
(white CD) and can be downloaded from www.dhinstruments.com.

7.2.7

Editing and Viewing Q-RPT Calibration Information

 PURPOSE
View and/or edit Q-RPT calibration information fields including:•

The calibration date – This field is normally used to record the date on which the Q-RPT
is calibrated.

•

The value of absolute mode AutoZero Poffset (Axxx Q-RPTs only) – See Section 3.2.22
for complete AutoZero information. This value is normally set to zero following absolutemeasurement mode calibration of an Axxx Q-RPT.

•

The value of PA – The pressure adder for the selected Q-RPT (see 7.2.1.1).

•

The value of PM – The pressure multiplier for the selected Q-RPT (see 7.2.1.1).

•

Absolute and negative gauge measurement modes ON or OFF (Axxx Q-RPTs only)– See Section 3.2.11 for complete information on measurement modes. This is set to
OFF if the Axxx Q-RPT was calibrated in gauge mode with a gauge pressure standard(see Section 7.2.5).

 OPERATION Caution
As editing PA and PM values will change the calibration of the Q-RPTs,
the edit function should only be used by qualified personnel as part of thecalibration process. Caution should be taken to avoid accidental editing.
A user level security system is available to control access (see Section
3.2.26.5).

Note•

A new PPC4 is delivered with PA and PM values set to zero and 1 for
all ranges. This does not mean that the PPC4 has not been calibrated.
In the original factory calibration, privileged factory coefficients areused for calibration with the user PA and PM set to zero and 1.

•

PA is always in units of Pascal (Pa). PM is dimensionless.

•

PPC4 may also use external Q-RPTs mounted in RPM4 Reference
Pressure Monitors. Viewing and adjustment of RPM4 calibration
information is performed locally on the RPM4, not through PPC4 (seethe RPM4 Operation and Maintenance Manual).

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PPC4™ OPERATION AND MAINTENANCE MANUAL

7.2.7.1

Basic Interface

To access Q-RPT calibration information viewing or editing press <Spec>,<Cal>. Select the desired Q-RPT. <View> displays the calibration information
fields. <Edit> displays the fields and allows them to be edited. The display is:1.

Date of last calibration in YYYYMMDD format.

2.

Position designator of the Q-RPT being
viewed.

3.

Current value of absolute mode Poffset.
This line is blank if the Q-RPT is not an Axxx
type

Cal date:20021117 IH
AbsPoffset:0.0
Pa

If in edit mode, the calibration information fields can be edited. Edits to Poffset arecommon with changes made in the AutoZ edit or run function (see Section
3.2.22).  on the last field continues to the next view/edit screen:
1.

Value of PA.

2.

Position designator of the Q-RPT being
viewed.

3.

Value of PM.

PA: 0.0
PM: 1.000000

Pa

IH

If in edit mode, the calibration fields can be edited. If the selected Q-RPT is an
Axxx Q-RPT, pressing  in the PM field continues to the next calibration
information display (this display is skipped if the Q-RPT is an Gxxx or BGxxx):

1.

Position designator of the Q-RPT being
viewed.

2.

Cursor is on current ON or OFF selection.

Absolute andneg g mode: ♦Off ♦On

If in edit mode, the OFF or ON status can be changed by selecting <Off> or<On> (see Section 7.2.5).  in view mode returns to the view/edit screen. in edit mode goes to confirmation of change activation if changes have been made.
 from any edit screen exits the edit screen without activating any changes.

7.2.7.2

Advanced Interface

To access the Calibration Coeffiients use [Settings], <More >>>, <Calibration>.
Hi or Lo RPT PA, PM and Cal Date can be viewed and edited by using[Settings], <More >>>, <Calibration>, <Hi RPT> or <Lo RPT>, <Calibration>.
Cal Date: Enterthe(yyyymmdd)

Cal

Date

in

year/month/day

format

PA: Enter PA in units of Pa
PM: Enter PM (dimensionless)Gauge Only: On to prevent Absolute or Negative Gauge modes with
an Absolute Q-RPT (see Section 7.2.5).

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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATION

To view and edit the Poffset values for the Hi or Lo RPT use [Settings],<More >>>, <Calibration>, <Hi RPT> or <Lo RPT>, <AutoZ> (See Section
5.7.5.1).
Absolute AutoZ: On to turn AutoZ On, Off to turn Absolute AutoZ Off
Absolute Poffset: Value of Poffset (AutoZ offset) in Absolute mode
Gauge AutoZ: On to turn Gauge AutoZ On, Off to turn Gauge AutoZ Off
Gauge Poffset: Value of Poffset (AutoZ offset) in Gauge mode
[OK] to accept changes and return to the Main Run Screen. [Back] to return to<Calibration> and make no changes. [Esc] or  to exit to the Main Run
Screen and make no changes.

7.2.7.3

Q- RPT Uncertainty

 PURPOSE
Configure end edit the settings for calculation and display of Q-RPT live
uncertainty (see Section 3.2.29).
 OPERATIONThe Uncertainty functions are located in [Settings], <More >>>, <Calibration>,<Hi RPT> or <Lo RPT>, <Uncertainty1> or <Uncertainty2>.

7.2.7.3.1

Uncertainty1

This screen controls display and type of uncertainty as well as uncertainty inhead height.
Display: On to enable display of live uncertainty in Main Run
Screen, Off to disable display of uncertainty.
Type: Measured or Delivered (including control components)
Head Height: Uncertainty in head height (same units as Head)[OK] to accept changes and return to the Main Run Screen. [Back] to return to<Calibration> and make no changes. [Esc] or  to exit to the Main Run
Screen and make no changes.

7.2.7.3.2

Uncertainty2

This screen accesses values for uncertainty calculation components (seeSections 3.2.29.1 and 3.2.29.3).
%Reading: Relative uncertainty (% of Reading)%Span: Threshold uncertainty (% of AutoRange Span)
Scaling: Scaling factor%Max Span, AutoZ on: Zero stability with AutoZ on (% of Q-RPT span)%Max Span, AutoZ off: Zero stability with AutoZ off (% of Q-RPT span)[OK] to accept changes and return to the Main Run Screen. [Back] to return to<Calibration> and make no changes. [Esc] or  to exit to the Main Run
Screen and make no changes.

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7.2.8

Q-RPT Calibration/Adjustment without CalTool for
RPTs Software

 PRINCIPLE
The PPC4 Q-RPTs can be calibrated and adjustments made without using CalTool for RPTs
software. This requires:•

Applying pressures with a calibration standard and recording the pressures measured
by PPC4.

•

Calculating new PA and PM values and entering them.

•

Setting Poffset to zero for Axxx Q-RPTs.

 Caution
Before proceeding to calibrate a reference pressure transducer without
using CalTool for RPTs software, Sections 7.2.1, 7.2.2 and 7.2.3,
Calibration of Reference Pressure Transducers, Equipment Required,
Setup and Preparation should be reviewed thoroughly.

7.2.8.1

Basic Interface Operation

The typical procedure for calibrating a Q-RPT in a PPC4 with Basic User
Interface is:
Set-up and prepare the PPC4 for calibration (see Sections 7.2.2 and 7.2.3).
Select <RPT> from the Main Menu to choose the Q-RPT to be calibrated(see Section 3.2.5). Be sure to set the DF range (not an AutoRanged
range).
Select <Head> from the Main Menu to set the HEAD to zero (see Section
3.2.16). Select <Unit> from the Main Menu to set the desired pressure unitof measure (see Section 3.2.10). Select <Mode> from the Main Menu to set
the desired pressure measurement mode (see Section 3.2.11). Axxx
(absolute) Q-RPTs that will be used in gauge measurement mode only, may
be calibrated in gauge measurement mode with a gauge pressure standard(see Section 7.2.5).
Select <Spec>, <AutoZ> from the Main Menu to access the AutoZ function(see Section 3.2.22).
If calibrating in absolute measurement mode, turn AutoZ ON if it is left ON innormal PPC4 operation. If calibrating in gauge measurement mode, always
turn AutoZ ON.
Select <Spec>, <Cal>, <Hi RPT> or <Lo RPT>, <View>, read and record thecurrent values of PA and PM for the Q-RPT to be calibrated. If calibrating in
absolute mode, also record the value of Poffset.
Run the recommended calibration point sequence for the Q-RPT (see Section
7.2.4) recording the pressure applied by the standard and the PPC4 reading at
each calibration point. Dwell at least 90 seconds at each point after setting thereference pressure to allow full stabilization before taking data. The data
recorded is the “as received” data for this calibration.
Enter the calibration pressures and PPC4 readings into a spreadsheet.
Calculate the “non-corrected” PPC4 readings by backing out the PA, PM andPoffset (Poffset only in the case of Axxx (absolute) Q-RPTs in absolute mode)
recorded in Step above, following:
non-corrected reading = ((corrected reading - PA)/PM ) + Poffset
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Perform a linear regression to find the offset and slope that best fit the noncorrected PPC4 readings to the calibration standard pressures. The offset isthe new value of PA, the slope is the new value of PM.
Select <Spec>, <Cal>, <Hi RPT> or <Lo RPT>, <edit> and enter the new
calibration date and the new values of PA and PM for the Q-RPT and range
calibrated. If this is an Axxx Q-RPT used in absolute mode, edit the value ofPoffset to zero. If this is an Axxx Q-RPT and the calibration was performed ingauge mode, turn absolute and negative gauge modes OFF to avoid their being
used after the calibration (see Section 7.2.5).
Calculate as left data for the calibration if desired following:as left reading = (non-corrected reading • new PM) + new PA
Perform additional verification pressure runs as desired.

7.2.8.2

Advanced Interface Operation

The typical procedure for calibrating a Q-RPT in a PPC4-ui (with Advanced User
Interface) is:
Set-up and prepare the PPC4 for calibration (see Sections 7.2.2 and 7.2.3).
Activate the Q-RPT to be calibrated using [AutoRange], Range to choose
the Default Range of the Q-RPT (see Section 3.2.5). Be sure to set the DF
range (not an AutoRanged range).
Set the Head to zero using [Settings], <Pressure>, Head (see Section
3.2.16). Set the desired pressure unit of measure using [Settings],<Pressure>, Pressure Unit (see Section 3.2.10). Set the desired pressure
measurement mode using [Settings], <Pressure>, Measurement Mode (seeSection 3.2.11). Axxx (absolute) Q-RPTs that will be used in gaugemeasurement mode only, may be calibrated in gauge measurement modewith a gauge pressure standard (see Section 7.2.5).
Check the AutoZ function using the AutoZ shortcut (see Section 3.2.22).
If calibrating in absolute measurement mode, turn AutoZ ON if it is left ON innormal PPC4 operation. If calibrating in gauge measurement mode, always
turn AutoZ ON.
Use [Settings], <Calibration>, Hi RPT or Lo RPT, read and record the current
values of PA and PM for the Q-RPT to be calibrated. If calibrating in absolutemode, also record the value of Poffset from [Settings], <Calibration>, <AutoZ>,
Absolute Poffset..
Run the recommended calibration point sequence for the Q-RPT (see Section
7.2.4) recording the pressure applied by the standard and the PPC4 reading at
each calibration point. Dwell at least 90 seconds at each point after setting thereference pressure to allow full stabilization before taking data. The data
recorded is the “as received” data for this calibration.
Enter the calibration pressures and PPC4 readings into a spreadsheet.
Calculate the “non-corrected” PPC4 readings by backing out the PA, PM andPoffset (Poffset only in the case of Axxx (absolute) Q-RPTs in absolute mode)
recorded in Step above, following:
non-corrected reading = ((corrected reading - PA)/PM ) + Poffset
Perform a linear regression to find the offset and slope that best fit the noncorrected PPC4 readings to the calibration standard pressures. The offset isthe new value of PA, the slope is the new value of PM.

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Use [Settings], <Calibration>, Hi RPT or Lo RPT and write the new
calibration date and the new values of PA and PM for the Q-RPT and range
calibrated. If this is an Axxx Q-RPT used in absolute mode, use [Settings],<Calibration>, <AutoZ>, Absolute Poffset to edit the value of Poffset to zero.
If this is an Axxx Q-RPT and the calibration was performed in gauge mode, turnabsolute and negative gauge modes Off to avoid their being used after thecalibration by setting Gauge Only to On (see Section 7.2.5.
Calculate as left data for the calibration if desired following:as left reading = (non-corrected reading • new PM) + new PA
Perform additional verification pressure runs as desired.

7.3

Adjustment of an On-board Barometer PURPOSE
To adjust the output of the on-board barometer (see Sections 1.2.2.3 and 3.2.27.3).

Note
PPC4’s that have only Gxxx Q-RPTs (no Axxx, BGxxx or utility sensors) are NOT
equipped with an on-board barometer.
 PRINCIPLE
The on-board barometer output can be adjusted using PA and PM values in the same manner as
Q-RPTs (see Section 7.2.1.1).

Note
The on-board barometer is a low accuracy sensor used for measuring changes inatmospheric pressure over short periods of time (see Section 3.2.22) and linepressure for G15K and BG15K line pressure compensation. PPC4 measurement
uncertainty does not depend on the measurement uncertainty of the on-board
barometer.
 OPERATION

7.3.1

Basic Interface

To edit the values of PA and PM for the barometer, select <Spec>, <Cal>, <Barometer> from
the Main Menu. Set the calibration date [YYYYMMDD] and edit PA and PM. With security
set to <Off>, the values can be edited (see Section 3.2.26.5).
 to accept changes and return to the Main Run Screen.  to exit to the Main Run
Screen and make no changes.

7.3.2

Advanced Interface

To edit the values of PA and PM for the barometer, use [Settings], <Calibration>, Barometer.
Set the calibration date [YYYYMMDD] and edit PA and PM. With security set to Off,the values can be edited (see Section 3.2.26.5).
[OK] to accept changes and return to the Main Run Screen. [Back] to return to<Calibration> and make no changes. [Esc] or  to exit to the Main Run Screen and makeno changes.

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7.4

Adjustment of Utility Sensor

 PURPOSE
To adjust the output of the utility sensor, if present (see Section 1.2.2.2).
 PRINCIPLE
PPC4s that do not have a Q-RPT in the Internal, Hi position, have a utility sensor.
The utility sensor output can be adjusted using PA and PM values in the same manner as for the Q-RPTs(see Section 7.2.1.1).

Note•

The utility sensor is not intended to serve as a pressure reference for low
uncertainty, traceable measurement. It is for indication, pressure control
and system maintenance functions only.

•

PPC4 measurement uncertainty when using Q-RPTs does not depend on
the measurement uncertainty of the utility sensor.

 OPERATION
The procedure to adjust the output of the utility sensor is that same as for the calibration of an Internal, Hi (IH),
Standard Class, Q-RPT (see Section 7.2.4.1), but the calibration reference uncertainty can be between
0.01 and 0.05 % FS.

7.5

Pneumatic Control Module Configuration

 PURPOSE
To run an automated routine that adjusts automated pressure control coefficients or to return automatedpressure control coefficients to factory default values.
 PRINCIPLE
PPC4 uses factory configuration coefficients in the pressure control algorithms used for automatedpressure control. Changes in the pressure control elements over time or operation into an unusuallylarge test volume can cause pressure control performance to change. The PPC4 on-board configuration
routine automatically retunes the factory configuration coefficients to take these changes into account.
The Configuration function should be considered a maintenance function and only used to attempt toimprove pressure control when all other factors affecting pressure control have been examined andeliminated (for example leaks, restrictions in test lines, unstable pressure supply, unstable vacuum
supply). The configuration function may also be useful to speed up PPC4 pressure control when theminimum test volume is in excess of 500 cc.
In addition, the Configuration function allows pressure control parameters to be returned to factory default
values. This feature can be useful to return to known conditions after the on-board configuration function has
been run.

Note•

If the PPC4 Hi Q-RPT or utility sensor is an A350K or lower, theconfiguration routine should be run twice, once with a vacuum source
attached to the EXHAUST port and once without. If the PPC4 Hi
Q-RPT or utility sensor is greater than A350K, the configuration
routine can be run with or without a vacuum pump connected to the
EXHAUST port (use the most common configuration).

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•

7.5.1

The default AutoRange of the PPC4 Hi Q-RPT must be active for a
Configuration to run. (See Section 5.7.1).

Basic Interface Operation
 Caution
Poor control is usually caused by invalid control parameters, excessive
leaks and restrictions in the test system or other set up problems. These
problems should be identified and eliminated before resorting to use of
the configuration function (see Section 8).

To access the CONFIG function use <Spec>, <Internal>, <Config> in the Main Menu.
<Defaults> causes PPC4 to load factory default control coefficients. This feature can be
useful to return to standard conditions if a faulty Configuration routine has been activated or
the current configuration is no longer valid.
<Run> causes the pressure control module configuration routine to execute. Before running
Configuration, remove any external volume and plug the TEST(+) port. However, if there is aminimum anticipated test volume, for example, the G15K or BG15K DVU (see Section
2.3.7.2), leave the volume connected. Connect the normal supply pressure to the rear panel
SUPPLY port and perform a leak check.
If the PPC4 Hi Q-RPT or utility sensor is greater than
A350K, proceed directly to the <CAUTION:> screen
below. If not, the display is:

Config type:♦Vac ♦Atm

Select <Vac> or <Atm> depending on whether the EXHAUST port is at vacuum or
atmosphere. If the ControlRef setting (see Section 3.2.27.2) does not correspond to yourchoice, you will receive an error.
CAUTION: About to
set nn MPa g

The next display is:

This display warns the user that pressure will increase to roughly 50 % of the Hi Q-RPT
default range.  to continue if it is safe for PPC4 to set the indicated pressure.
<CFG> flashes in the lower right corner of the display. PPC4 pulses and slews pressure.
After about ten minutes, the user is asked whether or not to save the new configuration. If
the CONFIG function ran completely and without incident, use <Yes>. <No> to return to theMain Run Screen with no change to the pressure control coefficients.
If the PPC4 has a Hi Q-RPT less than or equal to A350K, repeat the configuration routine in
the other operating mode (<Vac> or <Atm>). If you never use the PPC4 in one of the two
conditions, it is not necessary to configure it in that condition.

 Caution
The configuration routine must be run with NO external volume connectedto the PPC4 (TEST(+) port plugged) unless a known minimum test volume
is always connected. After configuring with a volume connected to the
TEST(+) port, controlling pressure with a lower volume may result in poorpressure control.

Note
The effect of the Configuration function can be eliminated and control
coefficients returned to factory defaults by selecting <Spec>, <Internal>,<Config>, <Defaults>.

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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATION

7.5.2

Advanced Interface Operation
 Caution
Poor control is usually caused by invalid control parameters, excessive
leaks and restrictions in the test system or other set up problems. These
problems should be identified and eliminated before resorting to use of
the configuration function (see Section 8).

To access Control Configuration use [Tools], <System>, Control Configuration.
Set Default causes PPC4 to load factory default control coefficients. This feature can be
useful to return to standard conditions if a faulty Configuration routine has been activated or
the current configuration is no longer valid.
Before running a Configuration, remove any external volume and plug the TEST(+) port.
However, if there is a minimum anticipated test volume, for example, the G15K or BG15K DVU(see Section 2.3.7.2), leave the volume connected. Connect the normal supply pressure to
the rear panel SUPPLY port and perform a leak check.
To perform a Vacuum Configuration, connect a vacuum pump to the EXHAUST port. If theControl Reference (see Section 3.2.27.2) is not Vacuum an error will be displayed.
To perform an Ambient Configuration, make sure there is no vacuum applied to the
EXHAUST port. If the Control Reference (see Section 3.2.27.2) is not Atmosphere an error
will be displayed.
This display warns the user that pressure will increase to roughly 50% of the Hi Q-RPT
default range. [Yes] to continue if it is safe for PPC4 to set the indicated pressure.
<Running Vacuum configuration> or <Running ATM configuration> flashes above a
progress bar while the PPC4 pulses and slews pressure. After about ten minutes, the user is
asked whether or not to save the new configuration. [Yes] if the CONFIG function ran
completely and without incident. [No] to return to the Main Run Screen with no change to thepressure control coefficients.
If the PPC4 has a Hi Q-RPT less than or equal to A350K, repeat the configuration routine in
the other operating mode. If you never use the PPC4 in one of the two conditions, it is notnecessary to configure it in that condition.

 Caution

7.6•

The configuration routine must be run with NO external volume
connected to the PPC4 (TEST(+) port plugged) unless a known
minimum test volume is always connected. After configuring with avolume connected to the TEST(+) port, controlling pressure with alower volume may result in poor pressure control.

•

The effect of the CONFIG function can be eliminated and control
coefficients returned to factory defaults by using [Tools], <Control
Configuration>, Set Default.

Reloading Embedded Software into Flash Memory

PPC4 uses FLASH memory. This allows the embedded software that controls PPC4 operations and functions
to be loaded into PPC4 over its COM1 port from a computer with a simple FLASH loading utility program.
To replace corrupted software or upgrade your software, access the DHI worldwide web site atwww.dhinstruments.com and go to embedded located under software. A Flash loading utility and thelatest PPC4 software are available for download at no charge. If you do not have access to the web or
have difficulty downloading or loading software, contact your DHI representative or a DHI Authorized
Service Provider for assistance.
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If you believe you have discovered an error or “bug” in PPC4 software, please report it with complete
details by email to cal.repair@dhinstruments.com or submit an on-line Quality Feedback Report atwww.dhinstruments.com.

Note
The DHI flash software loading utility and PPC4 embedded software are available
for download from DHI web site, www.dhinstruments.com.

7.7

Removing the PPC4 Cover Warning
To avoid electric shock, disconnect mains power before removing the top cover.

In order to access the internal components of the PPC4 it is necessary to remove the chassis cover. To
do so, first remove the eight screws that are on the top, right and left edges of the back panel. Then,
using the two M3 x 20 mm screws in the PPC4 accessory kit, gradually back the cover from the closed
and secured position using both screws. Once the cover is moved back by about 10 mm (0.4 inch) thenthe screws should be removed or retracted and the cover can be lifted off the chassis (see Figure 29).

Figure 29. Removing Back Cover

7.8

OverhaulNote
If calibration of the reference pressure transducers (Q-RPT) is included as part ofthe overhaul procedure, the calibration procedure should be performed last.

Any or all of the following items may be included as part of a system maintenance overhaul:•

Disassemble pressure control module filters and clean filter elements. Replace, if necessary.

•

Clean front panel.

•

Clean threads of rear panel fittings. Check for damage and replace, if necessary.
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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATION•

Check that rear panel cooling fan operates when PPC4 is On.

•

Check that internal screws, bolts and nuts are tight.

•

Verify that internal barometer, if present, reads atmospheric pressure within ± 0.1 kPa (0.015 psi).
Adjust if necessary (see Section 7.3)•

Verify that utility sensor, if present, indicates pressure with ± 0.1 % FS over its range. Adjust if
necessary (see Section 7.4).

•

Pressurize PPC4 to 90 % of maximum pressure and leak test. Select <Leak> in the Main Menu for
Basic Interface. Use the Leak Test shortcut from the Main Run Screen in the Advanced Interface(see Section 3.2.18). Leak rate, after stabilization, should not exceed 0.001 % of maximum pressure/second.

•Check the PPC4 controls within specifications over its range (see Section 1.2.3).

•

Perform calibration of Q-RPTs if necessary (see Section 7.2).

7.9

Subassembly Description and Location
 Warning
To avoid electric shock, disconnect mains power before removing the top cover.

 Display Pressure Control
Module Power Supply Module  Optional interfaces
 On-Board Barometer  Q-RPT Modules(if present)(configuration varies)

Figure 30. Internal View

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 Vacuum Sensor
 PowerPC board
 PPC4 driver board

PPC4™ OPERATION AND MAINTENANCE MANUAL

7.9.1

Power Supply Module•+ 12 V DC (± 2 %) @ 3.3 Amps: For internal and external valve actuation.

•+ 5 V DC (± 1 %) @ 3.0 Amps; + 15 V DC (± 3 %) @ 1.5 Amps; - 15 V DC (± 3 %)@ 0.35 Amps: For the supply of the micro board and driver board electronics.

7.9.2

PowerPC Board

The PowerPC board supports a Motorola PowerPC 8241 processor, EPROM, EEPROM,
128k x 8 bit NVRAM, 64 Mbit flash memory, 256 Mbit SDRAM memory; RS232
communications; and display control. An FPGA controls other ports and devices in PPC4.

7.9.3

Q-RPT MODULE

The Q-RPT module is an integrated assembly that mechanically manages the PPC4’spressure transducers. The module includes a Hi Q-RPT (quartz reference pressuretransducer) or utility sensor and may also have a Lo Q-RPT, brackets to hold thetransducer(s) interconnecting tubing, a manifold with the PPC4’s TEST (-), TEST(+) and
VENT ports and solenoid valves for AutoZeroing, measurement mode changes and switchingof the active transducer.
See Figure 32 for pneumatic schematics of different Q-RPT module configurations.

7.9.3.1

Hi Q-RPT or Utility Sensor

The higher range pressure transducer in a PPC4 may be a Q-RPT (quartz reference
pressure transducer) or a utility sensor depending on the specified PPC4 configuration.
A Q-RPT is intended to provide very high precision, low uncertainty, traceable
pressure measurement. The basic sensing principle is the measurement of thechange in the natural oscillating frequency of a quartz tuning fork in response tochanges in temperature and mechanical stress resulting from the change inpressure applied to a connecting bellows or bourdon tube. Two independent quartz
elements are used. One quartz element is subjected to pressure related stress.
The other quartz element is used only to monitor temperature. See Section
1.2.2.1 for Q-RPT specifications.
The utility sensor is for pressure indication, safety and housekeeping functions.
It is a temperature compensated micro-machined silicon sensor module.

7.9.3.2

Lo Q-RPT

PPC4 may be equipped with a Lo Q-RPT. The Lo Q-RPT provides a lower
measurement range than the Hi Q-RPT or utility sensor. See Section 7.9.3.1 fora description of Q-RPTs and Section 1.2.2.1 for complete Q-RPT specifications.

7.9.4

On-board Barometer

The on-board barometer supports a board mounted, barometric range, micromachined
silicon sensor and an ambient temperature sensor. The barometer readings are used for
dynamic atmospheric pressure compensation when measuring gauge pressure with anabsolute reference transducer (see Section 3.2.4). The temperature sensor is used fortemperature compensation of the barometric sensor.

Note
PPC4s that have Gxxx Q-RPTs (no Axxx, BGxxx or utility sensor) are NOT
equipped with an on-board barometer.
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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATION

7.9.5

Vacuum Sensor

The vacuum sensor is a silicon solid state pressure sensor in the barometric range. The vacuum
sensor readings are used to determine whether a atmospheric pressure or a vacuum
pressure is applied to the PPC4 EXHAUST port (see Section 3.2.27.2).

7.9.6

Pressure Control Module

The pressure control module is an integrated assembly that includes two inlet (fast and slow);
two exhaust (fast and slow) control valves; vent valve and differential pressure regulators.
The differential pressure regulators use pressure feedback to maintain a constant differential
pressure across the control valves. The control valves are solenoid type, actuated by 12 V.
See Figure 31 for the pneumatic module schematic.

7.9.7

Display

Basic Interface (PPC4):2 x 20 character vacuum fluorescent display.

Advanced Interface (PPC4-ui):5.7” TFT QVGA LCD (320x240).

7.9.8

Driver Board

The driver board is controlled by the PowerPC board (see Section 7.9.2). It supports:•

12 V drivers for internal and external solenoid valve actuation•

Frequency counters (4) for Q-RPTs (see Section 7.9.3.1)•

On-board barometer power and output (see Section 7.9.4)•

Vacuum sensor power and output for ControlRef function (see Section 3.2.27.2)•

Utility sensor power and output•

Power to the system cooling fan•

Keypad and display•

USB, IEEE-488.2 and TCP/IP communications•

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PPC4™ OPERATION AND MAINTENANCE MANUAL

7.10

Pneumatic Schematics
7.10.1Pressure Control Module

Note
Figure 31. Pressure Control Module Schematic

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7. MAINTENANCE, ADJUSTMENTS AND CALIBRATION

7.10.2

Q-RPT Module Configurations

ONE Q-RPT-Axxx or utility sensor only
(A14M)VALVE STATECONDITION

A

B

C

Vent

O

O

O

Measure/Control

C

O

C

Power offCOC

Valve C is shown for reference. It is in thepressure control module.

ONE RPT-Axxx or utility sensor(<A14M)
VALVE STATECONDITION

A

B

C

Vent

O

O

O

Measure/Control

O

C

C

Power offCOC

Valve C is shown for reference. It is in thepressure control module.

ONE RPT – Gxxx or BGxxx
CONDITIONVALVE STATE
A

B

C

D

Vent

O

O

O

O

Measure/Control

O

C

O/C

C

Power off

C

O

O

C

Valve C is the TEST (-) vent valve. In normal
operation with BGxxx or Gxxx Q-RPTs, this valve isclosed during fine pressure control (see Section
3.5.7.5).
Valve D is shown for reference. It is in the pressure
control module.

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PPC4™ OPERATION AND MAINTENANCE MANUALTWO RPTs – No Gxxx or BGxxx
VALVE STATECONDITION

A

B

C

Vent

O

O

O

Measure/Control Hi

C

O

C

Measure/Control Lo

O

C

C

Power offCOC

Valve C is shown for reference. It is in the pressure
control module.

TWO RPTs – One or Two Gxxx or BGxxx
CONDITIONVALVE STATE
A

B

C

D

Vent

O

O

O

O

Measure/Control
Hi

C

O

C/O

C

Measure/Control
Lo

O

C

C/O

C

Power off

C

O

O

C

Valve D is shown for reference. It is in the pressure
control module.
Valve C is the TEST (-) vent valve. In normal
operation with BGxxx or Gxxx Q-RPTs, this valve isclosed during fine pressure control (see Section
3.5.7.5).

Figure 32. Q-RPT Module Schematics for Various Configurations

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8. TROUBLESHOOTING

8.

Troubleshooting

PPC4 is a sophisticated pressure setting and measuring instrument with advanced on-board featuresand functions. Before assuming that unexpected behavior is caused by a system defect or breakdown,
the operator should use this manual and other training facilities to become thoroughly familiar with PPC4
operation. This troubleshooting guide is intended as an aid in identifying the reason for PPC4 behavior
and determining whether the behavior is due to normal operation or an internal or external problem.
Identify the symptom or unexpected behavior you are observing from the SYMPTOM list below.
A PROBABLE CAUSE is provided and a SOLUTION is proposed including references to manual
sections that provide information that may be of assistance.
Table 32. Troubleshooting GuideSYMPTOMPROBABLE CAUSE

Will not power up.
Cannot access certain functions>ACCESS RESTRICTED<

Blown fuse.
Security level has been set that restricts
access to certain functions.

Displays <FATAL ERROR> or<FATAL FAULT>.

Encountered unresolved internal software
conflict.

There is a leak through the PPC4EXHAUST port.

Normal flow through bypass of internalpressure controllers when pressure supply isconnected and system is not vented or OFF.

Front panel keys seem to bedisabled.
External RPM4 is not being
identified when PPC4 is powered
up or when an RPT search takes
place. PPC4 is unable to findexternal RPM4 and Q-RPT.
Valve driver #8 seems to be
operating erratically without being
told to do so.
Measured pressure display has
too much/not enough resolution.
Can’t increase resolution to level
desired in AutoRanged range.
Values that should be non-zero
are displayed as zero.
The pressure units available
under the <Unit> menu are notthe ones desired (Basic Interface)

SOLUTION<remote> command has been sent from ahost computer.

Replace fuse.
Change user level or consult systemmanager. 3.2.26.5
Cycle power to clear. Please record
conditions leading up to event including
the numbers displayed when  isused. Report to your DHI Authorized
Service Provider. Table 36
Operation is normal if flow rate is normal. If
there is flow through the EXHAUST port
when system is vented or OFF andcontroller is not a PPC4-10M, contact DHI
Authorized Service Representative.
7.8, 3.2.26.5
Send <local> command from hostcomputer or cycle PPC4 power. 6, 6.5.4

The RPM4 COM1 port settings are notcorrect.

Set RPM4 COM1 port to settingsrequired for use with PPC4. 2.3.6, 3.2.5

Driver #8 is used automatically by theautomated purge function when purge isactivated.

Deactivate purge function or don’t use
driver #8 other than to support an SPLT.
3.2.17
Use RES function to change theresolution setting. 3.2.19

Resolution setting needs to be changed.
Resolution setting is limited when
AutoRanging under 10 % of Q-RPT default
range.
Resolution setting needs to be increased toview significant digits.
UNIT menu needs to be customized.

Front panel display is dim (Basic
Interface).

Screen saver option has activated.

Front panel is blank with movingpressure or logo (Advanced
Interface)

Screen saver option has activated.

Page 207

Operation in normal. Table 5
Use Resolution function to change theresolution setting. 3.2.19
Use PresU function to customize the
UNIT function or reset units to default.
4.5.6
Operation is normal. Press any key toresume full screen power. Adjust screen
saver time, if desired. 3.2.26.1
Operation is normal. Press any key toresume full screen power. Adjust screen
saver time, if desired. 3.2.26.1

PPC4™ OPERATION AND MAINTENANCE MANUALSYMPTOMPROBABLE CAUSEThe external (RPM4) Q-RPT is not initialized.

AutoRange is not selecting thedesired Q-RPT for the specified
range.

The Q-RPT range does not cover the desired
AutoRange.
The Q-RPT is Gxxx (gauge only).

SOLUTION
Check that the external RPM4 is connected
and initialized properly. 2.3.6, 3.2.5
Check that Q-RPT default range is highenough to cover the AutoRange. Table 1
Check that the Q-RPT type supports thedesired measurement mode. 1.2.2.1,
3.2.11The specified operating mode is absolute or
negative gauge and absolute mode andnegative are OFF for the desired Q-RPT

Check that absolute/negative gauge is ON
for the Q-RPT. 3.2.4, 7.2.5

There is a <C> to the right of the<D> or <S> control modecharacter on the bottom line of thedisplay and it won’t go away.

The custom control function has been used.

Reset control parameters to default.
3.2.13Pressure display is flashing andbeeper is sounding intermittently.

Current upper or lower limit of active range
has been exceeded.

Correct overpressure condition.
Change UL and/or active range if
needed. 3.2.21, 3.2.21.1

Pressure display is flashing, no
beeper is sounding and directpressure control keys are inactive.

PPC4 and/or external RPM4 have been
over-pressured.

Correct the overpressure condition andcycle power ON and OFF. 3.2.21.1

Display is <Check Xaa aaa RPT,
wdog: nnnnn uuuum> andpressure control is aborted.
A Ready (green Ready/Not Ready
indicator) indication is neverachieved.
Q-RPT is Gxxx (gauge) but cannot
select absolute or negative gaugemeasurement mode.
Q-RPT is Axxx (absolute) but
cannot select absolute or negative
gauge measurement mode.

PPC4 internal watchdog measurement
system has detected that active external QRPT does not appear to be connected as its
pressure is not changing as expected when
PPC4 controls the pressure.
Control parameter settings are too tightand/or existing conditions will not allow
Ready to be achieved.

Operation is normal. 3.2.11

Absolute and negative gauge measurement
modes have been turned off in the calibration
function.

Check that absolute/negative gauge is ON.
7.2.5

Target exceeds UL and/or current range.

Will not set pressure.

Pressure and/or vacuum supply incorrectly
connected or not adequate.
There is a very large leak in the test system
or TEST(+) port is not connected.
Measurement mode is not negative gauge.
Vacuum source on EXHAUST port is needed.

Poor pressure control at low
gauge pressure.

Poor pressure control at low
gauge and/or absolute pressure.
Poor pressure control at very low
gauge pressure.
Poor pressure control at pressures
under atmosphere or inability toreach pressures underatmosphere.
Poor pressure control characterizedby control interrupting near thetarget pressure.

Adjust control parameters or correct otherconditions. 3.2.3, 3.2.12

Q-RPT is Gxxx and does not support
absolute and gauge measurement modes orWill not accept pressure command.

Will not set negative gaugepressure.

Check that external RPM4 Q-RPT isconnected properly to PPC4 TEST(+) port.
Cycle PPC4 power. 2.3.6

Ambient (atmospheric pressure) is too noisy
and/or not consistent on TEST (-) port and
UUT.
ControlRef not properly set to reflectpressure conditions at EXHAUST port.
DVU is needed, particularly if the Q-RPT is a
G15K or BG15K.

Check UL, range and measurement mode.
3.2.21, 3.2.8, 3.2.11
Correct pressure and/or vacuum supply.
2.3.4, 2.3.5
Correct leak. 2.3.8, 3.2.18
Set negative gauge mode if supported by
Q-RPT. 3.2.11
Connect vacuum source to EXHAUST port.
2.3.5
Connect TEST (-) ports of PPC4, RPM4s if
present and UUT together and consider
isolating from atmospheric pressure. 2.3.7,
2.3.8
Set Control Reference properly. 3.2.27.2
Install DVU on TEST(+) and TEST (-) ports.
2.3.7.2

Vacuum supply is incorrectly connected, is
not low enough or is unstable.

Correct vacuum supply to EXHAUST port.
2.3.5

Control mode is set to static mode rather
than dynamic mode.

Set control mode to dynamic. 3.2.2, 3.2.12

Page 208

8. TROUBLESHOOTINGSYMPTOMPROBABLE CAUSESOLUTION

There is a restriction in the test connection
between the PPC4 and the test or the PPC4,
the RPM4 and the test. Restrictions are
particularly problematic at low absolutepressures.

Remove the restriction to allow free flow
between the PPC4, the RPM4 (if present)
and the test. 2.3.7

Pneumatic control module needs to bereconfigured.

Reconfigure control module after all otherpossible control issues are considered. 7.5

The volume connected to the TEST(+) port is
too small.

Add volume to the system connected to the
TEST(+) port. 1.2.3

A filter in the PPC4, the SPLT or anaccessory is dirty and causing a restriction.

Clean and dry or replace the filter element.

Excessive leak present in system.

Correct internal or external leak or increase
hold limit. 3.2.18, 3.2.13

Test volume too small.

Increase test volume. Consider use of
DVU (Dual Volume Unit) if Q-RPT is
G15K or BG15K. Consider
reconfiguration of pneumatic module
after all other possible control issues
have been evaluated. 2.3.7.2, 7.5

Poor pressure control characterized
by minor overshooting.

Some overshooting is part of normal
operation to speed up pressure stabilization.

Check whether overshooting is within normal
limits. Objectively evaluate significance ofovershoot relative to UUT span andspecifications. Increase test volume.

Poor pressure control characterized
by very slow slew rate.

Test volume is too large. Severe restriction
in a test line.

Reduce test volume if slew rate is
unacceptable. Remove restrictions inline connected to TEST(+) port.

Poor pressure control.

Unstable or incorrect pressure supply.

Connect regulated pressure supply set tocor-rect supply pressure to SUPPLY port.
2.3.4

Poor pressure control andmeasurement.

The PPC4 and/or the connection to the test
system are contaminated with liquids.

Purge and clean affected systems. Consider
use of Self-Purging Liquid Trap. Contact
DHI Authorized Service Provider if PPC4
is contaminated internally. 2.3.7.1, Table
36

Disagreement between two Q-RPTs
in system appears excessive.

Difference is actually within tolerance andacceptable disagreement. Note the Internal,
Hi transducer may be a utility sensor which
has a much wider tolerance than a Q-RPT.

Compare differences observed totolerances on Q-RPT and/or utility sensor
measurements. 1.2.2.1, 1.2.2.2

Apparent inaccurate pressure control/
measure and little or no response
from Q-RPT or utility sensor:

Reference transducer destroyed byoverpressure.

Contact DHI Authorized Service Provider.
Table 36

Apparent inaccurate pressure
control/measure when using
Internal, Hi (IH) RPT.

The IH transducer is a utility sensor, not a QRPT.

Operation is normal for lower specificationsof utility sensor. 1.2.2.2

Incorrect pressure units and/or measurementmode (gauge or absolute).

Set desired pressure units and/or
measurement mode. Consider reference
temperature if unit is xxH2O. 3.2.10, 3.2.11

Q-RPT calibration coefficients have beenaltered.

Check and correct calibration coefficients ifneeded. 7.2

AutoZ has been run and turned ON with anincorrect standard for zero.

Check value of Poffset. Rerun AutoZ with avalid reference. 3.2.22

An unplanned “head” correction is active orhead height or gas is incorrect.

Operation is normal. Remove or change“head” correction. 3.2.16

Poor pressure control characterized
by excessive overshooting/undershooting and/or “hunting”
around target.

Apparent inaccurate pressure
measurement/control.

Apparent inaccurate pressure
measurement/control and <h> isdisplayed on top line of screen.

Page 209PPC4™ OPERATION AND MAINTENANCE MANUALSYMPTOM

Will not vent.

Will not vent while purging. Stuck atpressure during purging.

PROBABLE CAUSESOLUTION

System is vented but does not indicate zero
because measurement mode is absolute.

Check measurement mode setting andcurrent value of atmospheric pressure if
absolute. 3.2.11

VENT port is plugged.

Open VENT port to atmosphere.

Vent valve not operating.

Contact DHI Authorized Service Provider.
Table 36

Purge function is not activated, Purge
function is activated but no SPLT isconnected or SPLT valve is not operating.

Activate SPLT; correct SPLT connection or
repair SPLT exhaust valve. 3.2.27.4,
2.3.7.1

Page 210

9. APPENDIX

9.

Appendix

9.1

Drivers

The PPC4 drivers option provides eight open collector drivers for operating external valves, solenoids,
indicators, etc.
Each driver outputs 12 V, however the current sinking capacity of each driver is different. Refer to Table 33 forthe maximum current of each driver. The total current for all the activated drivers cannot exceed 2 Amps.
Table 33. External Drivers Current Output
DRIVERNUMBERMAX CURRENT
[mA]

1

1 000

2

500

3

500

4

200

5

160

6

135

7

120

8

100

The male connector (P/N 401382) for the DRIVERS port is delivered with the PPC4 accessories.
Table 34 and Figure 33 should be referred to when building a cable to utilize the drivers port.
Table 34. External Drivers Pin Outs
EXTERNAL DRIVERSPINADESCRIPTION
D1

Driver #1 (Open Collector)

C

D2

Driver #2 (Open Collector)

E

D3

Driver #3 (Open Collector)

G

D4

Driver #4 (Open Collector)

M

D5

Driver #5 (Open Collector)

J

D6

Driver #6 (Open Collector)

K

D7

Driver #7 (Open Collector)

L

D8

Driver #8 (Open Collector)

B

Drivers (+ 12 V)

D

Drivers (+ 12 V)

F

Drivers (+ 12 V)

H

Drivers (+ 12 V)

Figure 33. Drivers Connector Schematic

Page 211

PPC4™ OPERATION AND MAINTENANCE MANUAL

9.2

Unit Conversion
9.2.1

Pressure

PPC4 performs all internal calculations in SI units. Numerical values input or output in other units areconverted to SI immediately after entry and back to other units just before output as needed.
Table 30 provides the conversion coefficients used by PPC4 to convert numerical values
expressed in SI units to corresponding values expressed in other units.
Table 35. Pressure Unit of Measure Conversion Coefficients
TO CONVERT FROM Pa To

MULTIPLY BY

Pa

Pascal1.0

mbar

millibar

1.0 E-02

hPa

hecto Pascal

1.0 E-02

kPa

kilo Pascal

1.0 E-03barbar

1.0 E-05mmH2O @ 4°C

millimeter of water at 4°C

1.019720 E-01

mmH2O @ 20°C

millimeter of water at 20°C

1.019716 E-01

mmH2O @ 60°F

millimeter of water at 60°F

1.018879 E-01

mH2O @ 4°C

meter of water at 4°C

1.019720 E-04

mH2O @ 20°C

meter of water at 20°C

1.019716 E-04

mH2O @ 60°F

meter of water at 60°F

1.018879 E-04

mmHg @ 0°C

millimeter of mercury

7.50063 E-03

psi

pound per square inch

1.450377 E-04

psf

pound per square foot2.0885429E-02

inH2O @ 4°C

inch of water at 4°C

4.014649 E-03

inH2O @ 20°C

inch of water at 20°C

4.021732 E-03

inH2O @ 60°F

inch of water at 60°F

4.018429 E-03

inHg @ 0°C

inch of mercury

2.953 E-04

kilogram force per centimeter square

1.019716 E-05

mTorr

milliTorr (micron of mercury

7.50063

Torr

Torr (millimeter of mercury)7.50063 E-3

user

user

User defined coefficientft

feet of altitude

see Altitude Note belowmmeter of altitude

see Altitude Note below

kcm

2

Altitude Note: Quantities expressed in units of altitude follow MIL-STD-859A “Static
Pressure, p, in Inches of Mercury for Values of Pressure Altitude, H, in Geopotential
Feet.” MIL-STD-859A provides tables of pressure in inches of mercury as a function ofaltitude in feet. PPC4 uses a set of equations to model the pressure/altituderelationship. The worst case deviation between the MIL-STD-859A table and thecalculated pressure is 0.0001 inches of mercury (0.3 Pa). The pressure quantity
expressed in inches of mercury is converted to Pascal following Table 30 above. For
altitude expressed in meters, meters are converted to feet using 1 m = 3.28084 ft.

Page 21210. WARRANTY

10. Warranty
10.1

Overview
Table 36. DHI Authorized Service Providers
DH INSTRUMENTS, A FLUKE COMPANYAUTHORIZED SERVICE PROVIDERSCOMPANYTELEPHONE,
FAX & EMAILADDRESSNORMAL SUPPORTREGION

DH Instruments, a Fluke
Company

4765 East Beautiful Lane
Phoenix AZ 85044-5318
USA

Tel 602.431.9100
Fax 602.431.9559
cal.repair@dhinstruments.com

Worldwide

Minerva Meettechniek B.V.

Chrysantstraat 1
3812 WX Amersfoort
the NETHERLANDS

Tel (+31) 33.46.22.000
Fax (+31) 33.46.22.218
info@minervaipm.com

European Union

Ohte Giken, Inc.
Technology Center

258-1, Nakadai,
Kasumigaura-machi, Niihari-Gun
Ibaraki, 300-0133
JAPAN

Tel 81.29.840.9111
Fax 81.29.840.9100
tech@ohtegiken.co.jp

Japan/Asia

DHI Products Technical
Service Division

National Institute of Metrology
Heat Division
Pressure & Vacuum Lab
NO. 18, Bei San Huan Donglu
Beijing 100013
PR CHINA

Tel 010.64291994 ext 5
Tel 010.64218637 ext 5
Fax 010.64218703
cxcen@mx.cei.gov.cn

Peoples Republic of
China

Page 213

PPC4™ OPERATION AND MAINTENANCE MANUAL

Notes

Page 21411. GLOSSARY

11. Glossary
Axxx

A type of Q-RPT with a built-in vacuum reference that is intrinsically absolute (e.g. A10M).
Axxx Q-RPTs support absolute, gauge and negative gauge measurement modes.

Absolute Mode

Measurement mode in which the Q-RPT indicates absolute pressure (difference from vacuum).

AutoRange

A function that optimizes PPC4 measurement and control for a specific, user defined
range of operation.

AutoRanged Range

A PPC4 range created using the AutoRange function.

AutoTest or ATest

PPC4 on-board automated testing sequences and their results.

AutoZero or AutoZ

A process by which a Q-RPT and measurement mode is rezeroed (offset) relative to a standard.

Barometer

PPC4’s on-board atmospheric pressure measuring sensor. Also referred to as on-board
barometer.

BGxxx

A type of Q-RPT that is intrinsically gauge and is capable of operating bi-directionally,
above and below atmosphere, through zero). BGxxx Q-RPTs support gauge and negative
gauge measurement modes.

Bi-directional Gauge

Measurement mode in which the Q-RPT indicates gauge pressure (difference fromatmospheric pressure), in both positive and negative directions (above and below atmosphere)

Cockpit

PPC4 accessory software that runs on a PC a PC and emulates the Advanced Interface
front panel. When the PC is connected to the PPC4 basic or PPC4-ui, Cockpit gives full
Advanced Interface capability through the PC window. (see Section 6.2)

Control Mode

Type of automated pressure control (static or dynamic).

Control Parameters

Parameters affecting pressure control and the Ready/Not Ready determination (target,
hold limit, stability limit).

Custom Control

Automated pressure control in which the control parameters are not the default control
parameters.

Default Range (DF)A Q-RPT or utility sensor’s maximum range that is always available on [RANGE] andcannot be deleted.

Deviation

The deviation of the current pressure from the target pressure control value. Indicated in
Main Run Screen when in dynamic control mode.

DUT

Device Under Test. The device or devices pneumatically connected to the PPC4 TEST
port that the PPC4 is being used to test or calibrate. (see also UUT)

Dynamic Control

Control mode in which the pressure is constantly adjusted to remain as close as
possible to the target value.

External device orExternal Q-RPT

A Q-RPT in an RPM4 external to PPC4 used by PPC4 for precise pressure measurement.

FS

Abbreviation of “full scale”. The full scale value is the maximum pressure or the span ofa measurement range. Limits and specifications are often expressed as % FS.

Gxxx

A type of Q-RPT that is intrinsically gauge but only measures pressure greater thanatmosphere. Gxxx Q-RPTs support gauge measurement mode only.

Gauge Mode

Measurement mode in which the Q-RPT indicates gauge pressure (difference fromatmospheric pressure), but only in the positive direction (above atmosphere).

Head

A difference in height between the PPC4 reference level and the DUT.

Hold Limit

An automated pressure control parameter. Maximum acceptable difference between thecurrent pressure and the target pressure value.

IH or IuH

Internal, Hi. The Q-RPT (IH) or utility sensor (IuH) internal to PPC4 if there is only one
or, if there are two, the one that has the highest full scale default range.

ILInternal, Lo. Refers to a Q-RPT internal to the PPC4 that is the lower of the two if there
is a second Q-RPT or utility sensor in the PPC4.

Measurement Mode

Whether pressure is being measured relative to absolute zero or vacuum (absolute mode)or relative to atmospheric pressure (gauge mode).

Page 215

PPC4™ OPERATION AND MAINTENANCE MANUAL

Negative gauge,
compound gauge

Measurement mode in which the Q-RPT indicates gauge pressure (difference fromatmospheric pressure), in both positive and negative directions (above and below
atmosphere).

PoffsetThe difference between a Q-RPT reading and the AutoZero reference at the time AutoZ isrun. Used by the AutoZ function when Auto Z is ON to compensate Q-RPT readings forchanges in zero over time.

Pstd,0AutoZero reference value. Value indicated by the device against which the Q-RPT iszeroed by AutoZ.

PA

Pressure adder, used to offset a Q-RPT, utility sensor or barometer to calibrate it.

PM

Pressure multiplier, used to adjust span of a Q-RPT, utility sensor or barometer to calibrate it.

Q-RPT(Reference Pressure
Transducer)

1.

The transducer used by PPC4 for low uncertainty pressure measurement. The Q-RPT
in a single Q-RPT PPC4, or the higher pressure range Q-RPT in a dual Q-RPT
PPC4, is referred to as the Hi or Q-RPT.

2.

The lower pressure range Q-RPT in a dual Q-RPT PPC4 is referred to as the Lo QRPT.
Q-RPTs are designated by a leading A, G or BG (absolute, gauge or bi-directional
gauge) followed by three numbers and a letter indicating the maximum range of the
Q-RPT in kPa (nnnK) or MPa (nnnM).

Rate

The rate of change of the current measured pressure. Indicated in the Main Run Screen
when control is suspended.

Ready/Not Ready

Indication used to indicate when control PPC4 pressure meets specific criteria for
distance from target pressure and stability. Ready/Not Ready is indicated by an LED on
the PPC4 front panel and is used to determine when test readings should be taken.

RPM4

Reference Pressure Monitor manufactured by DHI. RPM4s can be set up to act as externalmeasurement devices to operate with PPC4.

Span

The difference between FS and the lowest point in a range. For example, the span of a
100 kPa FS range in negative gauge mode is nominally 200 kPa (from - 100 kPa to 100
kPa).

SPLT

Self Purging Liquid Trap. An optional device to automatically protect PPC4 from liquidand particulate contamination returned from a DUT.

Stability Limit

A limit expressed in units of pressure per second (e.g., kPa/second). The stability limit isused as the Ready/Not Ready criterion. Ready if rate of change is less than stability limit.
Not Ready if rate of change is greater than stability limit.

Static Control

Control mode in which the pressure is set near the target value and then shut OFF andallowed to evolve freely.

Target

The value to which automated pressure control sets and maintain the pressure.

UL

Same as Upper Limit.

Upper Limit

A range specific maximum value of pressure not be exceeded and at which PPC4 will abort
pressure setting and beep. In negative gauge measurement mode there is also a lower limit.

Utility Sensor

The internal, high (IuH) transducer in a PPC4 if when there is no Q-RPT in the IH position.
A utility sensor is a low accuracy pressure transducer used for pressure indication,
safety and housekeeping functions, not for low uncertainty measurement.

UUT

Unit Under Test. The unit or units pneumatically connected to the PPC4 TEST port that
the PPC4 is being used to test or calibrate.

User Level

Levels of security that can be set to protect certain PPC4 functions from being accessed.

X1H, X1L

External, Hi; External Lo: Position designators of Q-RPTs external to a PPC4 (inRPM4s) that have been connected to PPC4 and initialized so that they can be used by
PPC4 for pressure measurement.
“1” is the first RPM4 in the communications daisy chain. PPC4 does not support 2
remote RPM4 configurations.
“Hi” is the Q-RPT in the RPM4 if there is only one or the one that has the highest fullscale default range if there are two.
“Lo” is the lower of the two Q-RPTs if there are two Q-RPTs in the RPM4.

Page 216