RPM4™
Reference Pressure Monitor

Operation and Maintenance Manual© 2004-2007 DH Instruments, a Fluke Company

High pressure liquids and gases are potentially hazardous. Energy stored in these liquids and gases
can be released unexpectedly and with extreme force. High pressure systems should be assembled
and operated only by personnel who have been instructed in proper safety practices.

This instrument is not to be operated in any other manner than that specified by the manufacturer.

© 2004-2007 DH Instruments, a Fluke Company All rights reserved.
Information in this document is subject to change without notice. No part of this document may be reproduced or transmitted in any
form or by any means, electronic or mechanical, for any purpose, without the express written permission of DH Instruments, a
Fluke Company 4765 East Beautiful Lane, Phoenix AZ 85044-5318, USA.
DH Instruments makes sincere efforts to ensure accuracy and quality of its’ published materials; however, no warranty, expressedor implied, is provided. DH Instruments disclaims any responsibility or liability for any direct or indirect damages resulting from theuse of the information in this manual or products described in it. Mention of any product or brand does not constitute an
endorsement by DH Instruments of that product or brand. This manual was originally composed in English and was subsequently
translated into other languages. The fidelity of the translation cannot be guaranteed. In case of conflict between the English version
and other language versions, the English version predominates.
Products described in this manual are manufactured under international patents and one or more of the following U.S. patents:
5,142,483; 5,257,640; 5,331,838; 5,445,035. Other U.S. and international patents pending.
AutoRange, AutoZ, DH Instruments, DH, DHI, CalTool, COMPASS, RPM4, QDUT, Q-RPT, RPM4 and SDS are trademarks,
registered and otherwise, of DH Instruments, a Fluke Company.
Document No. 550129a-03
050815
Printed in the USA.

© 2004-2007 DH Instruments, a Fluke Company

TABLE OF CONTENTSTABLE OF CONTENTSTABLE OF CONTENTS ............................................................... ITABLES .................................................................................. V
FIGURES................................................................................ VI
ABOUT THIS MANUAL ............................................................ VII
1.

INTRODUCTION ................................................................. 1
1.1
1.2

PRODUCT OVERVIEW ...........................................................................................................................1
SPECIFICATIONS ...................................................................................................................................2
1.2.1
1.2.2
1.2.2.1
1.2.2.2
1.2.3

2.

INSTALLATION .................................................................. 7
2.1

UNPACKING AND INSPECTION ............................................................................................................7
2.1.1
2.1.2

2.2
2.3

2.4

SETUP .....................................................................................................................................................8
PREPARING FOR OPERATION ...................................................................................................................8
FRONT AND REAR PANELS ........................................................................................................................8
FRONT PANEL ..........................................................................................................................................8
REAR PANEL.............................................................................................................................................9
POWER CONNECTION.................................................................................................................................985 TO 264 VAC, 50/60 HZ VAC POWER ..................................................................................................9
BATTERY PACK ........................................................................................................................................9
REMOTE [ENT] CONNECTION (FOOTSWITCH OR OTHER SWITCH)....................................................10
CONNECTING TO MEASURE PRESSURE (TEST(+) AND TEST(-) PORTS)...........................................10
THE VENT OR ATM PORT..........................................................................................................................11
CHECK/SET SECURITY LEVEL .................................................................................................................11
TURN OFF ABSOLUTE AND NEGATIVE GAUGE MODE (AXXX RPT)....................................................12SDS FULL TIME OFF ..................................................................................................................................12
PARALLEL MEASUREMENT MODE..........................................................................................................12

POWER-UP AND VERIFICATION.........................................................................................................12
2.4.1
2.4.2
2.4.2.1
2.4.2.2

2.5

REMOVING FROM PACKAGING..................................................................................................................7
INSPECTING CONTENTS.............................................................................................................................7

SITE REQUIREMENTS............................................................................................................................8
2.3.1
2.3.2
2.3.2.1
2.3.2.2
2.3.3
2.3.3.1
2.3.3.2
2.3.4
2.3.5
2.3.6
2.3.7
2.3.8
2.3.9
2.3.10

3.

GENERAL SPECIFICATIONS .......................................................................................................................2
PRESSURE MEASUREMENT SPECIFICATIONS........................................................................................2
QUARTZ REFERENCE PRESSURE TRANSDUCER (Q-RPT) ................................................................2
ON-BOARD BAROMETER ........................................................................................................................4
BATTERY AND CHARGER PACK................................................................................................................5

SWITCH POWER ON ..................................................................................................................................12
CHECK PRESSURE MEASUREMENT OPERATION.................................................................................13
CHECKING ABSOLUTE MODE PRESSURE MEASUREMENT.............................................................13
CHECKING GAUGE MODE PRESSURE MEASUREMENT ...................................................................13

SHORT TERM STORAGE .....................................................................................................................14

OPERATION ..................................................................... 15
3.1

USER INTERFACE ................................................................................................................................15
3.1.1
3.1.2
3.1.3
3.1.4

3.2

MAIN RUN SCREEN....................................................................................................................................15
FUNCTION / DATA KEYPAD LAYOUT AND PROTOCOL.........................................................................17
REMOTE [ENT] (ENTER) FOOTSWITCH ...................................................................................................18
SOUNDS ......................................................................................................................................................18

GENERAL OPERATING PRINCIPLES .................................................................................................18
3.2.1

PRESSURE READY/NOT READY ..............................................................................................................18

Page I© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

3.2.2
3.2.3
3.2.4
3.2.5
3.2.6
3.2.7
3.2.8

3.3

DIRECT FUNCTION KEYS....................................................................................................................25
3.3.1
3.3.2
3.3.3
3.3.3.1
3.3.4
3.3.5
3.3.6
3.3.6.1
3.3.6.2
3.3.6.3
3.3.6.4
3.3.6.5
3.3.6.6
3.3.6.7
3.3.7
3.3.8
3.3.8.1
3.3.9
3.3.9.1
3.3.9.2
3.3.9.3
3.3.103.4[RANGE] ......................................................................................................................................................25[UNIT]...........................................................................................................................................................26[MODE] ........................................................................................................................................................27
DIFFERENTIAL MEASUREMENT MODE OPERATION .........................................................................29[AUTORANGE] ............................................................................................................................................30[LEAK CK] ...................................................................................................................................................33[DISPLAY]....................................................................................................................................................34
AVG (AVERAGE) .....................................................................................................................................36
RATE ........................................................................................................................................................37
DEV (DEVIATION) ...................................................................................................................................38
RPT ..........................................................................................................................................................39
HI/LO ........................................................................................................................................................40
FREEZE ...................................................................................................................................................41
CLEAN .....................................................................................................................................................41[HEAD] .........................................................................................................................................................42[SDS] (SELF DEFENSE SYSTEM) .............................................................................................................43
SDS IN DIFFERENTIAL AND PARALLEL MEASUREMENT MODES ....................................................46[AUTOZ] .......................................................................................................................................................46[AUTOZ] IN GAUGE AND NEGATIVE GAUGE MODE ...........................................................................47[AUTOZ] IN ABSOLUTE MODE...............................................................................................................48
AUTOZ IN DIFFERENTIAL MODE ..........................................................................................................51[ENT] (RUN AUTOTEST).............................................................................................................................51[SETUP] .................................................................................................................................................52
3.4.1
3.4.1.1
3.4.1.2
3.4.2
3.4.3
3.4.4
3.4.4.1
3.4.5

3.5

GAUGE AND NEGATIVE GAUGE MODES WITH AN AXXX (ABSOLUTE) Q-RPT, DYNAMIC
COMPENSATION FOR ATMOSPHERIC PRESSURE ...............................................................................19
MULTIPE RANGES (Q-RPTS, AUTORANGE AND INFINITE RANGING) .................................................20
PARALLEL MEASUREMENT MODE..........................................................................................................21
USING RPM4 WITH A PPC3 CONTROLLER/CALIBRATOR.....................................................................21
USE OF THE 12VDC BATTERY/CHARGER PACK ...................................................................................23
SDS SELF DEFENSE SYSTEM ..................................................................................................................24
DIRECT FUNCTION KEYS SUMMARY ......................................................................................................25<1RANGE> ..................................................................................................................................................52
SAVING AN AUTORANGE RANGE ........................................................................................................52
DELETING AUTORANGE RANGES........................................................................................................53<2RES> (RESOLUTION) .............................................................................................................................53<3STAB>......................................................................................................................................................54<4UL> (UPPER LIMIT) ................................................................................................................................55
OVER PRESSURE FUNCTION ...............................................................................................................57<5ATEST>....................................................................................................................................................57[SPECIAL] .............................................................................................................................................57
3.5.1
3.5.1.1
3.5.2
3.5.2.1
3.5.2.2
3.5.2.3
3.5.2.4
3.5.3
3.5.4
3.5.4.1
3.5.4.2
3.5.5
3.5.5.1
3.5.5.2
3.5.5.3
3.5.5.4
3.5.5.5
3.5.6
3.5.7
3.5.7.1
3.5.7.2
3.5.7.3
3.5.7.4
3.5.7.5
3.5.8
3.5.9
3.5.9.1
3.5.9.2
3.5.9.3
3.5.9.4
3.5.9.5<1AUTOZ> ...................................................................................................................................................58
EDIT AUTOZ ............................................................................................................................................62<2REMOTE> ................................................................................................................................................62<1COM1, 2COM2>...................................................................................................................................63<3IEEE-488> ............................................................................................................................................63<4FORMAT> ............................................................................................................................................63<5RS232 SELF-TEST> ............................................................................................................................64<3HEAD> .....................................................................................................................................................64<4SDS> ........................................................................................................................................................65<1TEMP OPEN/CLOSE> .........................................................................................................................65<2FULL TIME ON/OFF> ..........................................................................................................................66<5PREFS> ...................................................................................................................................................66<1SCRSVR> ............................................................................................................................................67<2SOUND> ..............................................................................................................................................67<3TIME>...................................................................................................................................................67<4ID>........................................................................................................................................................68<5LEVEL> (SECURITY)...........................................................................................................................68<6PUNIT>.....................................................................................................................................................71<7INTERNAL> .............................................................................................................................................73<1BARO> .................................................................................................................................................73<2READRT> ............................................................................................................................................74<3RPT2X>................................................................................................................................................75<4LO VNT> ..............................................................................................................................................76<5LOG>....................................................................................................................................................77<8CAL> ........................................................................................................................................................77<9RESET> ...................................................................................................................................................78<1SETS> ..................................................................................................................................................78<2 UNITS> ...............................................................................................................................................79<3ATEST>................................................................................................................................................79<4 CAL> ...................................................................................................................................................79<5 ALL> ....................................................................................................................................................80© 2004-2007 DH Instruments, a Fluke Company

Page IITABLE OF CONTENTS

4.

REMOTE OPERATION ....................................................... 81
4.1
4.2

OVERVIEW ............................................................................................................................................81
INTERFACING .......................................................................................................................................81
4.2.1
4.2.1.1
4.2.1.2
4.2.1.3

4.3

PROGRAMMING FORMATS.................................................................................................................82
4.3.1
4.3.2
4.3.2.1
4.3.2.2

4.4

ERROR QUEUE.........................................................................................................................................108
STATUS BYTE REGISTER .......................................................................................................................108
STANDARD EVENT REGISTER ...............................................................................................................110
READY STATUS REGISTER ....................................................................................................................110

IEEE STD. 488.2 COMMON AND STATUS PROGRAM MESSAGES................................................111
4.6.1

5.

PROGRAMMING MESSAGES ....................................................................................................................85
ERROR MESSAGESS.................................................................................................................................86
PROGRAM MESSAGE DESCRIPTION OVERVIEW ..................................................................................87
PROGRAM MESSAGE DESCRIPTIONS ....................................................................................................88

STATUS REPORTING SYSTEM ......................................................................................................... 108
4.5.1
4.5.2
4.5.3
4.5.4

4.6

CLASSIC PROGRAM MESSAGE FORMAT ...............................................................................................83
ENHANCED PROGRAM MESSAGE FORMAT ..........................................................................................83
USING COMMAND TYPE COMMANDS .................................................................................................83
USING QUERY TYPE COMMANDS ...................................................................................................84

COMMANDS ..........................................................................................................................................85
4.4.1
4.4.2
4.4.3
4.4.4

4.5

RS232 INTERFACE .....................................................................................................................................81
COM1 .......................................................................................................................................................81
IEEE-488 ..................................................................................................................................................82
COM2 .......................................................................................................................................................82

PROGRAM MESSAGE DESCRIPTIONS ..................................................................................................112

MAINTENANCE, ADJUSTMENTS A N D C A L I B R A T I O N . . . . . . . . . . . . . . . . 1 1 5
5.1
5.2

OVERVIEW ..........................................................................................................................................115
CALIBRATION OF QUARTZ REFERENCE PRESSURE TRANSDUCERS (Q-RPTS) ......................115
5.2.1
5.2.1.1
5.2.1.2
5.2.2
5.2.2.1
5.2.2.2
5.2.3
5.2.4
5.2.4.1
5.2.4.2
5.2.5
5.2.6
5.2.7
5.2.8

PRINCIPLE ................................................................................................................................................115
PA AND PM COEFFICIENTS ................................................................................................................116
AS RECEIVED AND AS LEFT DATA ....................................................................................................116
EQUIPMENT REQUIRED ..........................................................................................................................117
GAS OPERATED Q-RPTS, A10M AND LOWER ..................................................................................117
OIL OR GAS OPERATED Q-RPTS A14M AND HIGHER .....................................................................117
SET-UP AND PREPARATION...................................................................................................................118
RECOMMENDED CALIBRATION POINT SEQUENCE ............................................................................119
STANDARD CLASS Q-RPTS ................................................................................................................119
PREMIUM CLASS Q-RPTS ...................................................................................................................120
TURNING OFF ABSOLUTE AND NEGATIVE GAUGE ME AS URE ME NT MODE S FOR AXXX
(ABSOLUTE) Q-RPTS .........................................................................................................................122
Q-RPT CALIBRATION USING CALTOOL FOR RPTS SOFTWARE........................................................122
EDITING AND VIEWING Q-RPT CALIBRATION INFORMATION............................................................122
Q-RPT CALIBRATION/ADJUSTMENT WITHOUT CALTOOL FOR RPTS SOFTWARE.........................124

5.3

ADJUSTMENT OF ON-BOARD BAROMETER...................................................................................125

5.4

RELOADING EMBEDDED SOFTWARE INTO FLASH MEMORY......................................................126

5.5

SUBASSEMBLY DESCRIPTION AND LOCATION ............................................................................127
5.5.1
5.5.2
5.5.3
5.5.4
5.5.5
5.5.5.1
5.5.5.2
5.5.6

5.6

MINI MICRO BOARD .................................................................................................................................127
POWER SUPPLY MODULE ......................................................................................................................127
DRIVER BOARD ........................................................................................................................................128
ON-BOARD BAROMETER........................................................................................................................128
Q-RPT MODULE........................................................................................................................................128
HI Q-RPT MODULE ...............................................................................................................................128
LO Q-RPT MODULE ..............................................................................................................................128
DISPLAY ....................................................................................................................................................128

Q-RPT MODULE PNEUMATIC SCHEMATICS ...................................................................................129

Page III© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

6.

TROUBLESHOOTING .......................................................131

7.

APPENDIX ......................................................................135
7.1
7.2

REMOTE [ENT] ...................................................................................................................................135
UNIT CONVERSION ............................................................................................................................136
7.2.1

8.

WARRANTY ....................................................................137
8.1

9.

PRESSURE................................................................................................................................................136

OVERVIEW ..........................................................................................................................................137

GLOSSARY .....................................................................139© 2004-2007 DH Instruments, a Fluke Company

Page IVTABLES & FIGURESTABLES
Table 1. Reference Pressure Transducer (Q-RPT) Module Designations and Ranges ............................. 3
Table 2. RPM4 Packing List......................................................................................................................... 7
Table 3. Position Designators of Q-RPTs in an RPM4 System................................................................. 20
Table 4. Settings and What They Are Specific To (Range, Measurement Mode, Q-RPT, System) ......... 21
Table 5. Summary of RPM4 Function Key Operation................................................................................ 25
Table 6. Settings Made by AutoRange ...................................................................................................... 31
Table 7. AutoZ ON and OFF...................................................................................................................... 60
Table 8. Security Levels............................................................................................................................. 70
Table 9. UNIT Function - Available Units of Measure................................................................................ 72
Table 10. READRT - Display Update Rates .............................................................................................. 74
Table 11. Reset – Sets............................................................................................................................... 79
Table 12. Reset – Cal ................................................................................................................................ 80
Table 13. Reset – All.................................................................................................................................. 80
Table 14. COM1 Pin Designations and Connections ................................................................................ 81
Table 15. COM2 DB-9F Pin Designations ................................................................................................. 82
Table 16. Program Message List ............................................................................................................... 85
Table 17. Error #s and Descriptions .......................................................................................................... 86
Table 18. 8 Bit Status Byte Register ........................................................................................................ 108
Table 19. 8 Bit Standard Event Register.................................................................................................. 110
Table 20. 8 Bit Ready Status Register..................................................................................................... 110
Table 21. Program Message List ............................................................................................................. 111
Table 22. Calibration Point Sequence, Standard Class, Axxx and Gxxx Q-RPTs .................................. 119
Table 23. Calibration Point Sequence, Standard Class, BGxxx Q-RPTs................................................ 120
Table 24. Calibration Point Sequence, Standard Class, BA100K Q-RPT............................................... 120
Table 25. Calibration Point Sequence, Premium Class, Axxx and Gxxx Q-RPTs .................................. 121
Table 26. Calibration Point Sequence, Premium Class, BGxxx Q-RPTs ................................................ 121
Table 27. Troubleshooting Guide............................................................................................................. 131
Table 28. Pressure Unit of Measure Conversion Coefficients................................................................. 136
Table 29. DHI Authorized Service Providers ........................................................................................... 137

Page V© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUALFI G U R E S
Figure 1. Front Panel ................................................................................................................................... 8
Figure 2. Rear Panel .................................................................................................................................... 9
Figure 3. MAIN RUN Screen Display Fields .............................................................................................. 16
Figure 4. Keypad Layout ............................................................................................................................ 17
Figure 5. Battery Pack/Charger ................................................................................................................. 23
Figure 6. Status Register Schematic ....................................................................................................... 109
Figure 7. Internal View ............................................................................................................................. 127
Figure 8. Pneumatic/hydraulic schematics of RPM4 with Single Q-RPT Module ................................... 129
Figure 9. Pneumatic/hydraulic schematics of RPM4 with Two Q-RPT Modules..................................... 130
Figure 10. Remote [ENT] Connector Schematic ..................................................................................... 135© 2004-2007 DH Instruments, a Fluke Company

Page VIABOUT THIS MANUALABOUT THIS MANUALThis manual is intended to provide the user with the basic information necessary to operate an RPM4
reference pressure monitor. It also includes a great deal of additional information provided to allow you to
optimize RPM4 use and take full advantage of its many features and functions.
RPM4-AD is a special air data configuration of RPM4 which has its own dedicated manual, p/n
550148. This manual is for all other configurations of RPM4. If your are using an RPM4-AD (“-AD” infront panel configuration window) use the RPM4-AD Operation and Maintenance Manual p/n 550148.
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 RPM4 users. Section 3 is most important for thoseusing the local front panel interface but should be read over by all users to familiarize themselves withgeneral RPM4 operating principles. Section 4 is for remote operation from an external computer. Section 5
provides maintenance and calibration information. Section 6 is a quick troubleshooting guide. Use it totroubleshoot unexpected RPM4 behavior based on the symptom of that behavior. Certain words andexpressions have specific meaning as they pertain to RPM4. The Glossary, Section 6, is useful as aquick reference for exact definition of specific words and expressions as they are used in the manual.
For those of you who “don’t read manuals”, go directly to Section 2.3 to set up your RPM4 and then
go to Section 2.4 for power-up and verification. This will get you up and running quickly with a minimalrisk of causing damage to yourself or your new RPM4. THEN… when you have questions or start towonder about all the great features you might be missing, get into the manual!

Manual Conventions(CAUTION) is used in throughout the manual to identify user warnings and cautions.

(NOTE) is used throughout the manual to identify operating and applications advice andadditional explanations.
[ ] indicates direct function keys (e.g., [RANGE]).
< > indicates RPM4 screen displays (e.g., <1yes>).

Page VII© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUALNO T E S© 2004-2007 DH Instruments, a Fluke Company

Page VIII

1. INTRODUCTION

1.

INTRODUCTION

1.1

PRODUCT OVERVIEW

RPM4 is a stand-alone, microprocessor driven, reference pressure monitor intended to precisely
measure gas or liquid pressure in a wide variety of pressure calibration, measurement and testing
applications. It has been designed to provide very high performance and extensive features combinedwith maximum versatility and ease of use.
RPM4 uses one or two quartz reference pressure transducer (Q-RPT) modules and, in some cases abarometer, to measure pressure.
RPM4 can be controlled locally by the operator using its front panel display and keypad or remotely by acomputer using ASCII character command strings transmitted over its standard RS232 or IEEE-488.2
interface.
RPM4 models are available in ranges from as low as - 3 to 3 kPa (0.4 psi) to as high as 280 MPa (40 000 psi)in absolute, gauge, compound gauge and differential measurement modes.
RPM4 can be integrated into a PPC3 Pressure Controller/Calibrator System to serve the PPC3’s externalpressure measuring reference (see the PPC3 Operation and Maintenance Manual).
A special configuration of RPM4 designated RPM4-AD is available for air date (altitude andairspeed) applications. The RPM4-AD model has its own specific manual p/n 550148.

Page 1© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

1.2

SPECIFICATIONS
1.2.1

GENERAL SPECIFICATIONSPower Requirements

Operating Temperature Range
Storage Temperature Range
Vibration
Ventilation
WeightDimensions
Microprocessors
Communication Ports
Fuses
Pressure Ranges
Operating Medium
Pressure Connections

85 to 264 VAC, 50/60 Hz, 25 VA max consumption
and 12VDC, 1.2 A
15 to 35 °C- 20 to 70 °C
Meets MIL-T-28800D
To prevent product overheating, provide proper ventilation. Allow 10 cm(4 in.) clearance from rear panel cooling fan.
5 kg (11 lb) approx. (varies slightly with number and type of Q-RPT modules)
10 cm H x 22.7 cm W x 24 cm D (3.9 in. x 9.3 in. x 9.5 in.)
Motorola 68302, 16 MHz
RS232 (COM1, COM2), IEEE-488.2
1 A, 250 VAC fuse, 5 x 20 mm, time lag type fuse
Internal power supply fuse not replaceable by operator: 2.5A, 250 VAC
One or two independent quartz reference pressure transducer (Q-RPT)
modules cover vacuum to 280 MPa (40 000 psi)
Any clean, dry, non-corrosive gas or liquid. Q-RPTs less than 7 MPa full scale,gas only
Q-RPTs up to A70M
Q-RPTs > A70M
TEST(+):
1/8 in. NPT F
DH500 FTEST(-):
1/8 in. NPT F
None
VENT or ATM:
10-32 UNF (VENT)
10-32 UNF (ATM)
DH500 is a gland and collar type fitting for 6mm (1/4 in.) coned and left
hand threaded tubes equivalent to AE F250C, HIP HF4, etc.

Self Defense System (SDS™)
Pressure Limits

CE Mark

1.2.2

Included on all gas operated Q-RPT modules of A7M or lower. Isolates
Q-RPT module TEST(+) port and vents it to atmosphere. SDS is not included
with liquid filled Q-RPTs.
Maximum Working Pressure: 104 % Q-RPT maximum
Maximum Pressure Without Damage: 125 % Q-RPT maximum
Maximum SDS Protection Pressure: 10 MPa (1 500 psi):
Without Damage: 13 MPa (2 000 psi)
Available, must be specified

PRESSURE MEASUREMENT SPECIFICATIONS
1.2.2.1

QUARTZ REFERENCE PRESSURE TRANSDUCER (Q-RPT)

RPM4 can be configured with one or two quartz reference pressure transducer (Q-RPT)
modules to measure pressure. The type (Axxx, Gxxx, BGxxx, BAxxx) and range of
the Q-RPT module(s) determines the RPM4 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. Gaugepressure with an Axxx Q-RPT is defined by offsetting atmospheric pressure andapplying dynamic compensation for atmospheric changes using the on-board
barometer (see Section 3.2.2). Gxxx (gauge) Q-RPTs can measure positive gaugepressure only. BGxxx (bi-directional gauge) Q-RPTs can measure gauge andnegative gauge pressure. See Section 3.3.3 for additional information on
absolute, gauge and negative gauge measurement modes.
RPM4s configured with two Q-RPT modules have independent TEST ports and canmeasure separately. Two Q-RPTs can also be used together to operate indifferential mode (see Section 3.3.3.1) and parallel mode (see Section 3.2.4).
© 2004-2007 DH Instruments, a Fluke Company

Page 2

1. INTRODUCTION

Q-RPTs of A10M and lower are available with two different performancelevels, STANDARD class and PREMIUM class. See the product label on the
RPM4 rear panel, the Q-RPT module label on the rear panel and/or the
product calibration reports to determine the class of the Q-RPT(s) installedin RPM4.

Table 1. Reference Pressure Transducer (Q-RPT) Module Designations and Ranges
SI VERSIONMAXIMUM
RANGE
[psi]

Absolute

MAXIMUM
RANGE
[kPa]
Gauge

Absolute

Gauge

A280M-L1

280 000

280 000

40 00040 000

A200M-L1

200 000

200 000

30 00030 000

A140M-L1

140 000

140 000

20 000

20 000

A100M-L1

100 000

100 000

15 000

15 000A70M1

70 00070 000

10 000

10 000

A40M1

40 00040 000

6 000

6 000

A20M1

20 000

20 000

3 000

3 000

A14M1

14 000

14 000

2 000

2 000

1

10 000

10 000

1 500

1 500

7 000

7 000

1 000

1 000

3 500

3 500

500

500

A10M
A7M

1

A3.5M

1

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

A100K

1

110

10

16

1.5

A2M

1

A1.4M

110

--

G200K2

--

200

--

30

G100K2

--

100

--

15

2

--

15

--

2.2

--

±15

--

± 2.2

BA100K

G15K

BG15K
1.
2.
3.
4.

US VERSIONMAXIMUM
RANGE
[psi]

Q-RPT
DESIGNATIONMAXIMUM
RANGE
[kPa]

3

4

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).

Page 3© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

Warm Up Time
Resolution
Compensated Temperature Range
Acceleration Affect30 minute temperature stabilization recommended fromcold power up.
To 1 ppm, user adjustable
5 to 35 °C± 0.008 % /g maximum, worst axis
Allows operation at ± 20° from reference plane without
significant effectPredicted One Year Stability(all classes and types)1± 0.005% of reading

Q-RPTs UP TO A10M (1500 psi)

Precision2

Measurement Uncertainty3

STANDARD CLASSPREMIUM CLASS± 0.008% of reading or
0.0024% of Q-RPT span,
whichever is greater 4± 0.005% of reading, 0.0015%
of AutoRanged span, or
0.0005% of Q-RPT span,
whichever is greater 5± 0.01% of reading or 0.0030%
of Q-RPT span, whichever isgreater 4± 0.008 % of reading, 0.0024%
of AutoRanged span, or
0.0007% of Q-RPT span,
whichever is greater 5

Q-RPTs A14M TO A140M (2 000 to 20 000 psi)
Precision2± 0.012% of reading or 0.0036% of Q-RPT span, whichever isgreater 4

Measurement Uncertainty3± 0.013% of reading or 0.0039% of Q-RPT span, whichever isgreater 4

Q-RPTs A200M TO A280M (30 000 to 40 000 psi)
Precision2± 0.015% of reading or 0.0045% of Q-RPT span, whichever isgreater 4

Measurement Uncertainty3± 0.018% of reading or 0.0054% of Q-RPT span, whichever isgreater 4

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 forthe resolution and short term stability of 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 and calibration uncertainty, combined and expanded (k=2) following the ISO “Guide to theExpression of Uncertainty in Measurement.”
4. % 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 inpressure is 0.010% times the measured pressure to 48 kPa (160 kPa span x 30%) and 0.0048 kPa (160 kPa span x 30%
x 0.01%) under 48 kPa.
5. % of reading value times measured pressure from 100 to 30 % of AutoRanged span. Under 30% of AutoRanged span, % ofreading 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 in pressure 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 0.0025 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 inpressure is measured pressure x 0.008% to 14.4 kPa (160 kPa maximum Q-RPT span x 9%) and 0.0012 kPa (160 kPa maximum
Q-RPT span x 9% x 0.008%) under 14.4 kPa.

1.2.2.2

ON-BOARD BAROMETER

The on-board barometer is used only to measure changes in atmospheric pressure
to provide dynamic compensation of the Q-RPT’s atmospheric pressure offset whenusing an Axxx (absolute) Q-RPT to make gauge pressure measurements and forline pressure compensation of G15K and BG15K Q-RPTs.
There is no on-board barometer in RPM4s that have G100K or G200K
Q-RPTs only”.

© 2004-2007 DH Instruments, a Fluke Company

Page 4

1. INTRODUCTION

1.2.3

BATTERY AND CHARGER PACK
Power Requirements

100 to 240 VAC, 50/60 Hz, 15 W max consumption

Operating Temperature Range

0 to 50 °C

Storage Temperature Range- 20 to 50 °C

Vibration
WeightMeets MIL-T-28800D
2 kg (4.4 lb)

Dimensions

8 cm H x 22.5 cm W x 20 cm D (3.1 in. x 8.9 in. x 7.9 in.)Battery Type

Nickel Metal-HydrideBattery Voltage

12 VDC

Battery Capacity

Typical:Min:

Charge Time
Approx. Run Time, Full Charge

9000 mAh
8200 mAh

Full charge from empty, 14 to 16 hours approx.
8 to 12 hours

Page 5© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUALNO T E S© 2004-2007 DH Instruments, a Fluke Company

Page VI2. INSTALLATION

2.

INSTALLATION

2.1

UNPACKING AND INSPECTION
2.1.1

REMOVING FROM PACKAGING

RPM4 is delivered in a corrugated container with polyethylene inserts to hold it in place; or in
the optional molded, medium density polyethylene shipping case with a custom foam insert
for holding the RPM4.
Remove the RPM4 and its accessories from the shipping container and remove eachelement from its protective plastic bag.

2.1.2

INSPECTING CONTENTS

Check that all items are present and have no visible damage.
A standard RPM4 includes all items indicated in Table 2.
Table 2. RPM4 Packing List
DESCRIPTIONPART #

1 ea.

RPM4 Reference Pressure Monitor

FAM0081 ea.

Calibration Report

550100ACCESSORIES:

401967 (401967-CE)

1 ea.

Operation and Maintenance Manual

5501291 ea.

Power Cord (7.5 ft.)

1 ea.

Ferrite sleeve (snap on to COM2 cable for CE)

103303

1 ea.

General Accessories Disk (white CD)

102987100770 (100770-CE)

OPTIONAL BATTERY/CHARGER PACK

401904 (401904-CE)

1 ea.

Battery/charger pack4019801 ea.

Battery/charger pack to RPM4 cable

4019791 ea.

Power Cord (7.5 ft.)

100770 (100770-CE)

1 ea.

Instruction Sheet

560062

Page 7© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

2.2

SITE REQUIREMENTS

Install RPM4 on a flat, stable surface at a convenient height. The front feet can be extended so that theunit can be inclined for easier viewing. The RPM4 can also be mounted in a standard 19 in. rack mountusing the optional rack mount kit.

2.3

SETUP
2.3.1

PREPARING FOR OPERATION

To prepare RPM4 for check out and operation:
Remove the plastic caps from the RPM4 rear panel pressure connections.
Remove the protective plastic sheet from the front panel display.
Familiarize yourself briefly with the front and rear panels (see Section 2.3.2).

2.3.2

FRONT AND REAR PANELS
2.3.2.1

FRONT PANEL

1. Ready/Not Ready Indicator
2. Display
3. Remote Activity Indicator

4. Cursor Control Keys
5. Multi-Function Keypad

Figure 1. Front Panel© 2004-2007 DH Instruments, a Fluke Company

Page 8

2. INSTALLATION

2.3.2.2

REAR PANEL

10. TEST(+) Pressure Port, Lo Q-RPT(if Lo Q-RPT present)
11. TEST(-) Pressure Port, Lo Q-RPT(if Lo-QRPT present, <A100M only)
12. TEST(+) Pressure Port, Hi Q-RPT
13. TEST(-) Pressure Port, Hi Q-RPT(<A100M only)
14. VENT (<A10M>) or ATM (>A10M)
Pressure Port, Lo Q-RPT
15. VENT or ATM Pressure Port, Hi Q-RPT
16. Product Label (bottom of case)

1. 12VDC Power Supply
Connection
2. Remote [ENT] Connector
3. IEEE-488 Connector
4. COM2 Connector
5. COM1 Connector
6. Power Switch
7. Fuse8. Electrical Power Connector(IEC-320-C13)
9. FanFigure 2. Rear Panel

2.3.3

POWER CONNECTION
2.3.3.1

85 TO 264 VAC, 50/60 HZ VAC POWER

Check that the RPM4 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 85 to 264 VAC,
50/60 Hz.

2.3.3.2

BATTERY PACK

Charge the battery pack fully (see Section 3.2.6).
Connect the RPM4 12VDC power connection on the rear panel of the RPM4
to the 12 VDC power connection on the battery/charge pack using the cablesupplied with the pack.
See Section 3.2.6 for additional information on battery/charger packoperation and maintenance.

Page 9© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

2.3.4

REMOTE [ENT] CONNECTION (FOOTSWITCH OR OTHER
SWITCH)

Connect the optional remote ENTER footswitch, if available or a user supplied switch fitted tothe optional cable (see Section 7.1). Connect the cable to the RPM4 rear panel connection
labeled REMOTE ENTER. Activating the switch is equivalent to pressing the [ENT] key on
the front panel (see Section 3.1.3).

2.3.5

CONNECTING TO MEASURE PRESSURE (TEST(+) ANDTEST(-) PORTS)

Using a pressure connecting hose or tube of appropriate pressure rating, connect the device
or system to be tested to the RPM4 TEST(+) port.
The RPM4 TEST(+) connection is 1/8 in. NPT female (Q-RPTs of A70M or lower) or DH500 F(Q-RPTs higher than A70M).
DH500 is a gland and collar type fittings for 6.35 mm (1/4 in.) coned and left handthreaded tubes. DH500 is equivalent to AE F250C, HIP HF4, etc.

The TEST(+) and TEST(-) ports on Q-RPT modules of A70M and lower are threaded into
the aluminum Q-RPT manifold. Take care in making and breaking fittings not to crossthread or otherwise damage the threads. It is recommended that an adaptor be
installed in the in Q-RPT manifold and make break operations be made on the adaptor
rather than the manifold.

SDS Self Defense System: Q-RPT modules designated A7M or lower include the SDS Self
Defense System. SDS, operated properly, allows a the Q-RPT TEST(+) port to be leftconnected to a pressure up to 10 MPa (1 500 psi) without damage to the Q-RPT.
Do NOT attempt to use SDS in this manner without first becoming thoroughly familiar
with its operation and limitations (see Sections 3.2.7, 3.3.8, 3.5.4).

Q-RPT MODULE TEST(+) AND TEST(-) PORTS
Q-RPT modules of A70M and lower have both TEST(+) and TEST(-) ports. Q-RPT modules
greater than A70M have a TEST(+) port only. See Section 5.6, Figure 8 for RPM4 Q-RPT
module TEST port configurations.
The TEST(+) port is connected to Axxx (absolute) Q-RPTs’ sole measurement port and to thehigh side of Gxxx or BGxxx (gauge or bi-directional gauge) Q-RPTs.
The TEST(-) port of Axxx and BGxxx Q-RPTs is connected to RPM4’s internal barometer.
The TEST(-) is connected to the low side of Gxxx (gauge) or Gxxx (bi-directional gauge)
Q-RPTs.
•When operating in absolute mode:
atmosphere.

•

When operating in gauge or negative gauge mode with a range greater than 50 kPa(7.5 psi): The TEST(-) port, if present, is normally left open to atmosphere. A possible
exception is when the device or system under test is in an ambient pressure that may differ
significantly from the ambient pressure around the RPM4. For example, if the RPM4 ismeasuring the pressure applied to DUTs in an environmental chamber, the pressure in theenvironmental chamber may be different from ambient pressure around the RPM4. In this© 2004-2007 DH Instruments, a Fluke Company

Page 10The TEST(-) port, if present, is left open to2. INSTALLATION

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 DUTs, be sure toopen it 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 RPM4 TEST(-) port(s) directly tothe low or reference side of the device under test to assure that these are at the samepressure. When using an Axxx Q-RPT, this connection must also be open to atmosphere.
When using a Gxxx or BGxxx Q-RPT, it is preferable that this connection not be open toatmosphere.
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 RPM4’s on-board
barometer.

Using the RPM4 with gas operated Q-RPTs connected to a system with liquidcontaminants without taking proper precautions to purge the system and test line may
cause contamination of the RPM4 that will require non-warranty service.

2.3.6

THE VENT OR ATM PORT

RPM4 Q-RPT modules of A7M and lower have a VENT port. The VENT port is connected to the
TEST(-) port when SDS is CLOSED (see Section 5.6, Figure 8). For Axxx and BGxxx Q-RPTs,
the RPM4 on-board barometer, is connected to the VENT port when SDS is CLOSED.
The VENT port should always be left completely unobstructed and open to atmosphere.
RPM4 Q-RPT modules of A10M and higher have an ATM port. The ATM port is connectedto the RPM4 on-board barometer. The ATM port should always be left completely unobstructed
and open to atmosphere.
NEVER plug, obstruct or connect a supply pressure to the RPM4 VENT or ATM port. This
may adversely affect GAUGE mode operation and AutoZeroing functions.

2.3.7

CHECK/SET SECURITY LEVEL

RPM4 has a security system based on user levels. By default, the security system is set to“low”, which includes access restriction to internal calibration coefficients, and there is no
password required to change the security level. See Section 3.5.5.5 for information on the
security level system. As part of the RPM4 startup, determine the security level that is
appropriate for the RPM4 and set a password if desired.
RPM4 is delivered with the security level set to “low” to avoid inadvertent altering of criticalinternal settings but with access to changing security levels unrestricted. It is recommended
that the low security level be maintained at all times and password protection be
implemented if control over setting of security levels is desired.

Page 11© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

2.3.8

TURN OFF ABSOLUTE AND NEGATIVE GAUGE MODE
(AXXX RPT)
If your RPM4 has one or two Axxx (absolute) Q-RPTs, it is able to operate ingauge, negative gauge and absolute measurement modes (see Section 3.3.3).
If the RPM4 will be used in gauge mode only, the other measurement modes canbe turned off so they are no longer accessible. Turning off modes that are notneeded can avoid confusion and/or accidental use of the wrong measurement mode.
See Section 5.2.5 for complete information on turning off absolute and negative
gauge measurement modes.
Turn off absolute and negative gauge mode if desired.

2.3.9

SDS FULL TIME OFF
Gas operated Q-RPT modules of A7M or less, include the SDS Self Defense
System (see Section 3.2.7) to shut off the Q-RPT from the TEST(+) port. If thisfunction is not desired, SDS can be turned full time off so that in regular
operation, SDS is not present. With SDS full time off, the SDS overpressure
protection is still active.
See Section 3.5.4.2 for instructions on turning SDS full time off if desired.

2.3.10

PARALLEL MEASUREMENT MODE
If your RPM4 has two Q-RPTs of the same type (Axxx, Gxxx, BGxxx), it supports
parallel measurement mode in which both RPTs are used simultaneously tomeasure a common pressure, statistically reducing uncertainty in themeasurement. Parallel measurement creates a new Q-RPT, designated <HL>,
which is the combination of the Hi and Lo Q-RPTs. See Section 3.2.4 forcomplete information on parallel measurement mode.
Turn on parallel measurement mode if desired.

2.4

POWER-UP AND VERIFICATION
2.4.1

SWITCH POWER ON

Actuate the power switch on the RPM4 rear panel (if a 12 VDC power supply is already connectedto the 12 VDC connection, RPM4 power is already on). Observe the front panel display as
RPM4 initializes, error checks and goes to the MAIN RUN screen (see Section 3.1.1).
RPM4 default power-up condition is Hi Q-RPT active, SDS closed if present.
If the RPM4 fails to reach the MAIN RUN screen, service is required. Record the sequenceof operations and displays observed.
If the RPM4 Q-RPT module is equipped with SDS, SDS is CLOSED at power up and theTEST(+) port is shut off. This causes <SDS CLOSED> to be flash periodically in the main
run screen in place of the measured pressure value.

© 2004-2007 DH Instruments, a Fluke Company

Page 12

2. INSTALLATION

2.4.2

CHECK PRESSURE MEASUREMENT OPERATION
2.4.2.1

CHECKING ABSOLUTE MODE PRESSURE MEASUREMENT

If the RPM4 has an Axxx (absolute) Q-RPT, check that it operates properly inabsolute mode.
Make sure that the TEST(+) port is vented to atmosphere.
Use the [RANGE] function key to select the Axxx (absolute) Q-RPT DF range(see Section 3.3.1).
Press the [MODE] function key and select <absolute> mode (see Section 3.3.3).
Use [UNIT] to change the pressure unit if desired (see Section 3.3.2).
If SDS is CLOSED (<SDS CLOSED> flashes over the display of pressure on
the top line of the display), OPEN SDS. Press [SDS], <2yes> to OPEN SDS(see Section 3.3.8).
Do NOT OPEN SDS with a pressure higher than the maximum pressure of the
Q-RPT applied to the TEST(+) port. Damage to the Q-RPT may result.
Observe the current value of atmospheric pressure. Check that the value agrees
with the local value of atmospheric pressure within measurement tolerances (seeSection 1.2.2.1) Repeat this process for both Axxx (absolute) Q-RPTs if there
are two in the RPM4. . If a Q-RPT does not agree within tolerance, it may need
to be AutoZeroed (see Section 3.3.9), calibrated (see Section 5.2)
or repaired.

2.4.2.2

CHECKING GAUGE MODE PRESSURE MEASUREMENT

Make sure that the TEST(+) port is open to atmosphere.
Press the [MODE] function key and select <gauge> mode. Use [UNIT] to change
the pressure unit if desired (see Section 3.3.2)..
If SDS is CLOSED (<SDS CLOSED> flashes over the display of pressure on the
top line of the display), OPEN SDS. Press [SDS], <2yes> to OPEN SDS.
Do NOT OPEN SDS with a pressure higher than the maximum pressure of the
Q-RPT applied to the TEST(+) port. Damage to the Q-RPT may result.
The value indicated should be near zero. It is normal for the Q-RPT to indicate
a value other than zero when vented when gauge mode is first entered or therange is changed. Press [AutoZ]. This runs AutoZ to zero the Q-RPT reading(see Section 3.3.9.1). Upon return to the main run screen, observe that theindication of measured pressure has zeroed.
If the display fails to zero properly, RPM4 may need repair.

Page 13© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

2.5

SHORT TERM STORAGE

The following is recommended for short term storage of RPM4:
Vent the RPM4 test port
Switch power OFF.

© 2004-2007 DH Instruments, a Fluke Company

Page 14

3. OPERATION

3.

OPERATION

3.1

USER INTERFACE

RPM4 is designed to offer a balance between simple, straight forward operation and the availability of awide variety of advanced functions with a high level of operator discretion. The local operator interface isthrough a 2 x 20 character alphanumeric display, a function/data keypad, a cursor control pad and a
Ready/Not Ready indicator.
Remote communications are by RS232 (COM1) and IEEE-488. See Section 4 for information on remotecommunication.

3.1.1

MAIN RUN SCREEN

The RPM4 MAIN RUN screen is its home display that is reached on power-up and fromwhich other functions and menus are accessed. It is the very top level of all menu structures.
The MAIN RUN screen is where RPM4 is left in normal operation. It displays the current
measured pressure as well as a variety of additional information if desired.
Figure 3 and its legend summarize the RPM4 MAIN RUN screen fields and their functions.
RPM4 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 the display. The screen saver time canbe changed or screen saving can be completely suppressed (see Section 3.5.5.1).

Page 15© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUALPRESSURE1UNITM hzRR
DDISPLAYFUNCIONnn/nn

DISPLAY FIELDNAMEPURPOSECONTENTSSECTION

1. PRESSURE1

Measuredpressure

Displays pressure
measured by theactive Q-RPT

Numerical pressure value and sign.
Intermittently flashes <SDS
CLOSED> when the Q-RPT is shut
off from the TEST(+) port by SDS.

1.2.2.1

2. UNIT

Unit ofmeasureIdentifies unit ofmeasure in whichpressure values are
displayed

Pressure unit abbreviation

3.3.2

3. M

Measurement
mode

Identifies
measurement modeof displayed pressure

<a>
<g>
<d>

absolutegauge or negative gauge
differential

3.3.3

4. h

Head
pressure
indicator

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

3.3.7

5. z

AutoZeroindicator

Indicates whether
the AutoZero function
is ON or OFF for theactive Q-RPT andmeasurement mode<z>
AutoZ is ON<blank> AutoZ is OFF

3.5.1

6. RR

ActiveQ-RPT
position
indicator

Indicates the positionof the active Q-RPTin the RPM4

<Hi> Hi Q-RPT<Lo> Lo Q-RPT<HL> Hi and Lo Q-RPTs together inparallel measurement mode
<Hd> Hi and Lo Q-RPTs together indifferential measurement
mode

3.2.3

7. nn/nn

Sequence
progress
indicator

Indicates progress of
ATest sequence,
during test execution<NN/NN> Number of this point
over total number of points
in the sequence

3.3.108. DISPLAY
FUNCTION

Information
specific to
the DISPLAY
mode

Pressure indication
depending on current
RPM4 DISPLAY
function. Leading
character identifies
the value

Numerical pressure value
and sign.
<PPC3 EXT DEV:> when the RPM4
is initialized as an external device
to a PPC3 pressure controller.

3.3.6

9. D

Pressure
information
indicator

Pressure information
indicator depending
on current RPM4DISPLAY function.

<σ>

3.3.6

Display mode is AVERAGE
and value is standard deviation<R> Display mode is RATE andvalue is pressure rate ofchange per second<H> Display mode is HI/LO andvalue is high, then low<D> Display mode is DEVIATION
and value is difference fromcurrent target<), ↑ , ↓ > Display mode is RPT
and value is measurementof inactive RPT<F> Display mode is FREEZE andvalue is last captured reading
Blank, no character Current
display mode is CLEAN

Figure 3. MAIN RUN Screen Display Fields© 2004-2007 DH Instruments, a Fluke Company

Page 16

3.2.7

3. OPERATION

3.1.2

FUNCTION / DATA KEYPAD LAYOUT AND PROTOCOLThe RPM4 has a function/data keypad for local operator access to directfunctions, function menus and for data entry.

1. The Function/Data keys allow very commonlyused functions to be accessed directly by asingle keystroke when pressed from theMAIN RUN screen (see Section 3.1.1).
The name of the function is on the bottom
half of the key. These keys enter numericalvalues when editing.
2. The Editing and Execution keys are forstarting and suspending command execution,
cursor control in menus and editing entries.

3. The Menu/Data keys provide access tofunction menus when pressed from theMAIN RUN screen. The menu name is on
the bottom half of the key. The SETUP
menu is for more frequently used functions(see Section 3.4). The SPECIAL menu is forfunctions that are not generally used as a partof day to day operation (see Section 3.5).
These keys enter numerical values when editing.

Figure 4. Keypad Layout

Pressing the [ENT] key generally causes execution or forward movement in themenu tree.
Pressing the [ESC] key moves back in the menu tree and/or causes execution tocease or suspend. Pressing [ESC] repeatedly eventually returns to the MAIN RUN
screen and, from there, allows momentary viewing of the RPM4 introduction
screen.
Pressing the [+/-] key changes a numerical sign when editing. It also toggles
through multiple screens when available and, from some run screens, is a
shortcut to a momentary display of active RANGE.
Pressing the [ ], [ ], [ ] and [ ] keys allows up, down, reverse andforward cursor movement when editing data entry or moving in menus.
Some screens go beyond the two lines provided by the display. This isindicated 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 or directly enter the number of the hidden menu choice if you know it.

Page 17© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

3.1.3

REMOTE [ENT] (ENTER) FOOTSWITCH

The optional remote ENTER function is a switch that duplicates the function of the front panel[ENT] key. The remote ENTER function is serviced by a connector on the RPM4 rear panel.
An optional footswitch is available to activate remote entry hands free or a different switch
may be used. See Section 7.1 for information on remote ENTER switch wiring.
The remote ENTER feature can be particularly convenient when running AutoTests(see Section 3.3.10) in which using a footswitch to [ENT] allows hands free operation. It canalso be used, with the FREEZE display function (see Section 3.3.6.6) to capture theactivation point of a pressure switch.

3.1.4

SOUNDS

RPM4 is equipped with a variable frequency tone device to provide audible feedback andalarms. The beeper is used for the following indications.

3.2

Valid key press

Brief beep. Choice between three frequencies or NO
sound is available (see Section 3.5.5.2).

Invalid key press

Descending two tone “blurp”

Leak check completed

Three two second beeps (see Section 3.3.5).

Upper or lower limit exceededIntermittent one second beeps (see Section 3.4.4).

Pmax! (overpressure limit)
exceeded

Eight second high frequency beep (see Section 3.4.4.1).

Parallel measurement modepossible disconnection of the
Hi and Lo Q-RPTs

Rapid beeps for 8 seconds (3.2.4).

AutoTest in/out of tolerance
reading

Ascending triad/descending triad (see Section 3.3.10).

GENERAL OPERATING PRINCIPLES
3.2.1

PRESSURE READY/NOT READY

There is a Ready/Not Ready indication LED on the RPM4 front panel. This indication isintended to provide the user with a clear and objective indication of when a stable pressure
has been achieved. Ready is indicated when the current stability (rate of change) ofpressure is less than the stability limit. The user can set the stability limit (see Section 3.4.3).
The ready indication is often used when comparing the RPM4 and a test device to indicate
when a valid reading can be made.
In RPM4s with two Q-RPTs, the Ready/Not Ready indication always applies to the active
Q-RPT, whose pressure measurement is displayed on the top line of the RPM4 display.
When the inactive Q-RPT measurement is displayed on the second line using the RPT
display mode, the Ready/Not Ready indication for the inactive RPT is indicated by theleading character on the line. <)> indicates Ready. < ↑ > or < ↓ > indicate Not Ready,pressure increasing or pressure decreasing.

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3. OPERATIONThe Ready/Not Ready LED indications are:<Green >Pressure Ready

The pressure stability is within the stability limit.

<Red>

Pressure Not Ready

The pressure stability is NOT within the stability limit.

In differential measurement mode (see Section 3.3.3.1), the LED Ready/Not Ready
indication applies to the differential pressures.
In parallel measurement mode (see Section 3.2.4), the LED Ready/Not Ready indication
applies to the average pressure read by the <HL> Q-RPT.

When RPM4 is being used as an external measurement reference of a PPC3 pressure
controller, the Ready/Not Ready indication is still based on the RPM4 stability andstability limit only. The RPM4’s Ready/Not Ready LED does not indicate whether the
PPC3 pressure control is Ready.

3.2.2

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 for gauge andnegative gauge measurement modes (see Section 3.3.3,  PRINCIPLE). Gauge measurement
modes are achieved by subtracting the value of atmospheric pressure, Poffset,G, from the
Q-RPT’s absolute reading using AutoZ (see Section 3.2.2). The AutoZ routine that measures
Poffset,G, is run by pressing [AutoZ] whenever RPM4 is in the vented condition. This assuresthe continuous 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 may change between opportunities to run AutoZ and update
the value of Poffset,G, for example when running an extended test without venting. RPM4 uses
dynamic compensation for atmospheric pressure to correct for changes in atmosphericpressure between opportunities to run AutoZ and update Poffset,G. When AutoZ runs, andPoffset,G is determined, the reading of RPM4’s on board barometer, Patm,0, is also recorded.
Later, when no longer vented, the change in atmospheric pressure, ΔPatm, since Poffset,G was
updated, is the difference between the current barometer reading, Patm, and the barometerreading at the time of AutoZ execution, Patm,0:ΔPatm = Patm - Patm,0Dynamic compensation for atmospheric pressure uses ΔPatm to correct the value of Poffset,G,thus always compensating real time for changes in atmospheric pressure:Pgauge = Pu - Poffset,G - ΔPatm
Gauge pressure measurement on an Axxx (absolute) Q-RPT allows instantaneous switching
between gauge and absolute measurements modes. The additional uncertainty in gaugepressure mode due to the dynamic compensation for atmospheric pressure technique is afunction of the resolution and short term stability of the on-board barometer, not its absolutemeasurement uncertainty. This additional uncertainty is ± 1 Pa (0.00015 psi).

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RPM4™ OPERATION AND MAINTENANCE MANUAL

3.2.3

MULTIPE RANGES (Q-RPTS, AUTORANGE AND INFINITERANGING)An RPM4 may have one or two Q-RPTs. Position indication of the currently active Q-RPT is
continuously displayed in the upper right hand corner of the MAIN RUN screen and most otherscreens. See Table 3 for position designation protocol for the Q-RPTs in an RPM4.
See Table 1 for a complete listing of RPM4/RPM4 Q-RPT choices and their default ranges.
Table 3. Position Designators of Q-RPTs in an RPM4 System
Q-RPT POSITIONDISPLAY SYMBOL*

Q-RPT with highest maximum pressure,installed in HIGH RPT position

Hi

Q-RPT with lower maximum pressure indual Q-RPT RPM4, installed in LOW
RPT position.

Lo

Two Q-RPTs being used simultaneously
in parallel measurement mode

HL

Hi Q-RPT when used in differential
measurement mode

Hd

* The display symbol is included in the upper, right hand corner of most RPM4
menu displays as a convenient indicator of the active Q-RPT.

An RPM4 may have multiple ranges. Each RPM4 Q-RPT has a default range which is its
maximum span. Additional ranges, lower than the Q-RPT’s maximum span, may also becreated using AutoRange (see Section 3.3.4). Ranges created using are AutoRange
temporary but may be saved with all their settings for reactivation (see Section 3.4.1).
AN RPM4 range is identified by a range screen showing the Q-RPT used by the range, its current unitof measure and its full scale pressure in gauge and absolute (if available) measurement modes.
The range screen is:
1.

Q-RPT designator.

2.

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

3.

Q-RPT position designator.

4.

Current pressure unit of measure.

5.

Full scale pressure in current unit of measure in gauge (<g>) and/or absolute(<a>) measurement mode depending on type of Q-RPT and range.

Active A700K
DF Hi
psi
100g/100a

The ranges available on an RPM4 system are accessed using [RANGE] (see Section 3.3.1)
and/or created using [AutoRange] (see Section 3.3.4).
Most settings made in an RPM4 range, such as unit of measure, measurement mode, display
resolution, and stability setting are specific to the range. Settings selected while one range isactive apply to that range and not to other ranges. The range specific settings are stored withthe range and recalled whenever the range is made active. This makes setting up ranges a
convenient way to store and recall frequently used operating configurations. See Table 4 for a listingof RPM4 adjustments and settings and whether they are range, Q-RPT or system specific.

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3. OPERATION

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

Set pressure unit of measure

Range

3.3.2

[Mode]

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

Range

3.3.3

[Display]

Set bottom line display function

System

3.3.6[Head]

Set fluid head correction height, fluid, unit ofmeasureSystem

3.3.7

[SDS]

Open and close SDS

Q-RPT

3.3.8

[AutoZ]Run AutoZ

Q-RPT and measurement mode

3.3.9

Resolution

Set pressure display resolution

Range

3.4.2

Stability

Set Ready/Not Ready stability test.

Range

3.4.3

Upper Limit

Set upper and lower pressure limit alarm

Range and measurement mode

3.4.4

AutoZ

AutoZ, ON/OFF, set and view values

Q-RPT and measurement mode

3.5.1

Screen Saver,Sound, Time,
ID, Level

Set system user preferences

System3.5.5

Lo vntSet status of TEST(-) vent valve, if present

Q-RPT

3.5.7.4

Cal

Various Q-RPT and barometer calibration
functions, including turning off absolute andnegative gauge modes

Q-RPT or barometer

3.5.8

3.2.4

PARALLEL MEASUREMENT MODE

RPM4s equipped with two Q-RPT modules of the same type (Axxx, Gxxx, BGxxx) can be set
to operate in parallel measurement mode.
Parallel measurement mode is intended to improve measurement reliability and reduce measurement
uncertainty by using the measurements of two Q-RPTs together. In parallel measurementmode, the measured pressure is the average of the readings of the two Q-RPTs.
Parallel measurement mode is considered a third Q-RPT designated <HL> (combination of
Hi and Lo). Once it has been set up, the HL Q-RPT can be selected using the [RANGE] key
and operated with all the features of a Hi or Lo Q-RPT. When setting up parallel measurement,
the Hi and Lo Q-RPTs can be suppressed so that only the HL Q-RPT is active. This feature isused when the RPM4 will always be used in HL mode.
Parallel measurement mode is set up using [SPECIAL], <7internal>, <3RPT2x>(see Section 3.5.7.3).

3.2.5

USING RPM4 WITH A PPC3 CONTROLLER/CALIBRATOR

RPM4 can be integrated as a reference pressure measuring device in a PPC3 Pressure
Controller/Calibrator System. See the PPC3 Operation and Maintenance Manual for
information on setting up RPM4 to operate as the PPC3’s external device.
Before an RPM4 is used with a PPC3, the following settings should be made:SDS

Close SDS on all Q-RPT modules on which SDS is available (see Section 3.2.7).

Head

If the RPM4 TEST port is at a different level than the PPC3’s TEST port AND theRPM4 will be used in absolute measurement mode, set the RPM4 head height to
the PPC3’s TEST port level so that RPM4 is corrected to indicate the pressure at
the level of the PPC3 TEST port (see Section 3.3.7).

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RPM4™ OPERATION AND MAINTENANCE MANUAL

AutoZ

Make sure AutoZ is ON for all RPTs and measurement modes (see Section 3.5.1).

Certain RPM4 settings may be changed when an RPM4 is operated with a PPC3. Settings
that may be changed when an RPM4 is used as a PPC3 external device include:
SDS

Closed or open status may be changed and SDS full time off will beoverwritten to full time on (see Sections 3.3.8, 3.5.4)

AutoRange range

May be rewritten (see Section 3.3.4).

Display

When an RPM4 is initialized by PPC3 as an external device, thesecond line of the RPM4 display is <PPC3 EXT DEV: IDLE>. When
the RPM4 is the active Q-RPT being used by the PPC3, the secondline of the RPM4 display is <PPC3 EXT DEV: ACTIVE>

Range

Active range may be changed (see Section 3.3.1).

Unit of measure

Active unit may be changed (see Section 3.3.2).

Measurement mode

Active mode may be changed (see Section 3.3.3).

Lo Vent

Setting may be changed (see Section 3.5.7.4).

Communications

For a PPC3 to be able to identify and communicate with an RPM4,
the RPM4’s COM1 port must be set to:
Baud rate 9200 to 19200
ParityEven

Data bits

7

Stop bit1

When RPM4 is activated by a a PPC3, the PPC3 sets the RPM4
COM1 port baud rate to 19200. The COM1 port keeps this setting
until power is cycled. Cycling power restores the previous baud ratesetting. The same is true for the COM2 of the first RPM4 in a chainof two RPM4s used with a PPC3.
When RPM4 is initialized as an external device to a PPC3 pressure controller, the RPM4
front panel keypad is locked out and the second line of the display becomes:<PPC3 EXT DEV: IDLE>(if RPM4 is initialized by PPC3 but not currently in use)
<PPC3 EXT DEV: ACTIVE> (if RPM4 is initialized by PPC3 and is currently in use)
After using an RPM4 as an external device for a PPC3, cycle power to return to theprevious RPM4 settings, restore front keypad capability and return to the normal main
run screen.

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3. OPERATION

3.2.6

USE OF THE 12VDC BATTERY/CHARGER PACK

An optional 12VDC battery/charger pack is available to supply power to RPM4s 12VDC
power connection (see 1.2.3).
The battery/charger pack combines the battery and the battery charger.
To Charge the Battery
The battery may be charged while the battery/charge pack is connected to the RPM4.
To charge the battery, connect the battery/charger pack to a 100 to 240 V, 50/60 Hz power
supply using the supplied power cable and turn on the charger power switch. The green
CHARGE indicator light goes on to indicate that battery charging is in progress. Allow 14 to
16 hours for the battery to charge fully. When the battery is fully charged, the CHARGE
indicator light flashes.
When the battery charger power switch is in the ON, the battery is connected to the charger,
not the 12VDC output. When the battery charger switch is in the OFF position, the CHARGE
indicator light goes off, and 12VDC is supplied on the 12VDC connection.
To Use the Battery/Charger Pack to Supply RPM4
After charging the battery, connect the 12VDC connection of the battery/charger pack to the
12VDC connection on the RPM4 rear panel.
Turn the battery/charger pack power switch to OFF (when AC power is connected to thebattery/charger pack, the power switch must be OFF for 12VDC power to be output).
When RPM4 is connected to both a 12 VDC source and an AC source,if the RPM4 powerswitch is OFF, the 12VDC source supplies the RPM4; if the RPM4 power switch is ON, the12 VDC source is disconnected and the AC source supplies the RPM4.
To Check the Battery Charge Level
To check the current charge level of the battery, press the toggle switch on thebattery/charger pack front panel. Observe the BATTERY CHECK indicator lights. All threelights are lit when battery is fully charged. If no light or one light is on, the battery should be
recharged.

Figure 5. Battery Pack/Charger

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RPM4™ OPERATION AND MAINTENANCE MANUAL

3.2.7

SDS SELF DEFENSE SYSTEM

Q-RPT modules designated 7M or lower that are NOT liquid filled are equipped with the SDS self
defense system. The SDS system includes hardware and embedded software to isolate Q-RPTs
from overpressure. When SDS is CLOSED for a Q-RPT module, the Q-RPT is isolated from themodules TEST(+) port and opened to the modules VENT port (See Section 5.6, Figure 8).
SDS can be OPENED and CLOSED from the front panel using [SDS]. SDS can also becontrolled using functions under [SPECIAL], <4SDS>. The SDS “temp open/close” function
allows SDS on both Q-RPTs, whether active or inactive, to be opened and closed directly(see Section 3.5.4.1). The SDS “full time on/off” function allows SDS to be opened permanently
so the RPM4 can be operated as if SDS were not installed (see Section 3.5.4.2).
SDS is normally used to isolate an RPM4 Q-RPT from a test system which may sometimes
be subjected to pressures higher than the Q-RPTs maximum pressure. When configuring a
multi-range system, this can eliminate the need for external valving or connecting anddisconnecting RPM4s. For example, two Q-RPTs of different ranges might be connected toa single calibration system. When the Hi Q-RPT is in use, SDS is closed on the Lo Q-RPT toprotect it from overpressure. When used in this manner, SDS should be CLOSED prior toapplying pressure. Automatic SDS closing in response to overpressure should only be used inan emergency overpressure situation.
SDS also attempts to protect Q-RPTs from accidental overpressure. Whenever RPM4 ispowered ON it continuously monitors the pressure read by its Q-RPT(s). If the pressure
reaches the maximum pressure limit for a Q-RPT, SDS CLOSES to isolate the Q-RPT fromthe TEST port and vent it to atmosphere (see Section 3.4.4.1). This is not a fail safe
overpressure system. It does not protect against very rapid overpressure or pressure
exceeding 10 MPa (1 500 psi).
When an RPM4 is used as an external device to a PPC3 pressure controller, PPC3 controls the
RPM4’s SDS to isolate the RPM4 Q-RPTs from the test pressure when they are not in use.
IF the RPM4 SDS is “full time off” PPC3 changes it to “ON”.

The maximum pressure that should be applied to an RPM4 TEST(+) port when SDS is
CLOSED is 10 MPa (1 500 psi).

Though the SDS self defense system includes features to automatically protect Q-RPTs
against accidental overpressure, SDS should NOT be considered a fail-safe overpressure
protection system. SDS cannot guarantee that overpressure damage will NOT occur.
Conventional measures for overpressure protection should also always be used. Damage
to Q-RPTs due to overpressure is NOT covered by the RPM4 product warranty even when
SDS is present and ON.

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3. OPERATION

3.2.8

DIRECT FUNCTION KEYS SUMMARY
Table 5 provides a brief summary of direct function key operation. It may be useful to keep
a copy of this summary near the RPM4, especially when first becoming acquainted with
its operation.

Local operation of RPM4 is through the front panel keypad. To minimize multi-layered menu
structures, the keypad numerical keys also provide direct access to the most commonly usedfunctions. The function accessed is labeled on the bottom half of the key. Direct function
keys are active whenever RPM4 is in its MAIN RUN screen. Table 5 summarizes theoperation of the direct function keys.
Table 5. Summary of RPM4 Function Key Operation
DIRECT FUNCTION KEYS ARE ACTIVE FROM THE MAIN RUN SCREEN
See corresponding manual sections for full detail.
Adjust height of fluid headcorrection. Set to zero to defeat
correction.

View active range and toggle
through available ranges. [ENT] on
a range activates it.

.SDS controls the connection of
the Q-RPT to the TEST(+) port.
Close any open SDS. Open SDSof active Q-RPT if closed.

Select pressure unit of measure forthe active range. Choice of units
available in this menu can becustomized.

Run the AutoZ function to
AutoZero the active Q-RPT andmeasurement mode.

Select the pressure measurementmode for the active range (absolute,gauge, negative gauge, differential).

Set up and optimize RPM4
features for a specific operating
range and measurement mode.

Menu of less commonly used internalfunctions and settings.

Run automatedroutine.

Menu of commonly used setup
featuresincludingsave/delete
AutoRange ranges, set display
resolution, set stability limit, set
upper/lower, view AutoTest data

leakchecking

Select the display function for thebottom line of the RPM4 display.

3.3

Start or set functions such as Leak
Check, AutoTest and Freeze.
ENTER values when editing.

DIRECT FUNCTION KEYS
3.3.1

[RANGE] PURPOSE
To view and/or change the active pressure measurement range and associated settings.
 PRINCIPLE
An RPM4 range is defined as a pressure span and associated settings (see Section 3.2.3).
An RPM4 may have multiple ranges. Each Q-RPT in the RPM4 system has a default range
which is its maximum span. Additional ranges, lower than the Q-RPT’s maximum span, mayalso be created using AutoRange (see Section 3.3.4). Ranges created using AutoRange
may be saved, with their settings, for reactivation (see Section 3.4.1).
The [RANGE] function key allows the available RPM4 pressure ranges to be viewed and selected.

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RPM4™ OPERATION AND MAINTENANCE MANUAL OPERATION
Pressing the [RANGE] function key activates the range viewing and selecting function.
When the [RANGE] function key is first pressed, the active range is displayed. For example:
1.

Q-RPT designator.

2.

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

3.

Q-RPT 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 Hi
psi
100g/100a

Pressing the [+/-] key or the [RANGE] key again while in the RANGE functions toggles
through displays of the other available ranges, from lowest range to highest range.
To select a range to become the active range, press [ENT] while the range is displayed.
Pressing [ESC] while in the RANGE function returns to the MAIN RUN screen without
making a range change.
Range full scale limits are given in the pressure unit that is currently active for that range.

Pressing [+/-] from the MAIN RUN screen provides a shortcut to a momentary view of theactive range.

Many RPM4 settings and functions are range specific. See Table 4 for identification ofrange specific settings.

For best metrological performance, vent the RPM4 Q-RPT before changing ranges.

3.3.2[UNIT]

 PURPOSE
To select the unit of measure in which RPM4 displays pressure values.
For information on selecting the measurement mode (absolute, gauge, negative gauge,
differential), see Section 3.3.3.
 PRINCIPLE
RPM4 allows the unit of measure in which pressure values are displayed to be changed.
RPM4 supports 15 standard pressure units of measure as well as user defined units.
To simplify operation, quick access to six units is made available under the [UNIT] key.
The default units available depend on whether the RPM4 was originally configured as an SI
or US version. The [UNIT] key contents can be customized by the user to any configurationof six units (see Section 3.5.6).

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3. OPERATIONInternally, RPM4 always operates in Pascal (Pa), the SI unit of pressure. Values of pressure
are represented in other units by the application of conversion factors to convert from Pa(see Section 7.2.1).
 OPERATIONTo change the active pressure unit of measure for arange, press [UNIT] from the MAIN RUN screen while
the range is active. The display is:

1kPa 2Pa 3MPa
4hPa 5bar 6mbar

The cursor is on the number corresponding to the active pressure unit of measure for the active range.
To change the pressure unit of measure, select the desired unit.
returns to the MAIN RUN screen with the selected unit active.

Making the selection

The pressure unit of measure 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 current range unit. When the current unit is an altitudeunit, the range and upper limit indications are in kPa if the unit is meters (m) and psi if
the unit is feet (ft).

See Section 7.2.1 for tables of the conversion factors used by RPM4.

If the pressure unit selected is inWa (inches of water), the reference temperature for water
density must we specified in a separate menu (choices are 4ºC, 20ºC 60ºF). No reference
temperature selection is necessary for the unit mmWa as the only reference temperaturecommonly used for mmWa is 4 ºC.

The default pressure units of measure available under the UNIT function depend on whether
the RPM4 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 becustomized from a wider selection by the user (see Section 3.5.6). The units available under
the UNIT function can be reset to default by reset (see Section 3.5.9.2).

3.3.3[MODE]

 PURPOSE
To set the measurement mode (absolute, gauge, negative gauge or differential) for the active range.
For information on selecting the unit of measure, see Section 3.3.2.
 PRINCIPLE
RPM4 supports simple, one-step switching between up to four different measurement modes:
Absolute

Measures pressure relative to vacuum (zero is hard vacuum). Range isfrom zero absolute to full scale.
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RPM4™ OPERATION AND MAINTENANCE MANUAL

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).
Range is positive and negative from zero, negative to minus one
atmosphere and positive to full scale. With a BGxxx RPT, negative range
is the negative equivalent of the positive range.

Differential

Available only for the Hi Q-RPT in RPM4s equipped with two Q-RPT modulesof the same type (Axxx, Gxxx, BGxxx). Measures the difference between the
Hi and the Lo Q-RPT (Differential = Hi – Lo). Differential measurement modeis selected “on top of” the Hi Q-RPT’s base measurement mode (gauge,absolute or differential). Differential range is positive to maximum pressure of
the Hi Q-RPT and negative to the minimum pressure of the Lo Q-RPT basemeasurement mode (see Section 3.3.3.1 for specific information on operationin differential measurement mode).

Which measurement modes are available depends on the type of Q-RPT type(s) available.
There are three types of Q-RPTs:
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 offsetting of atmospheric pressure withdynamic compensation for atmospheric pressure changes between offsets using
an on-board barometer (see Section 3.2.2). Access to absolute and negative
gauge operation can be turned OFF (see Section 5.2.5). In RPM4s with two Axxx
Q-RPTs, differential measurement mode is supported on the Hi Q-RPT.

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 measurementin gauge mode only. In RPM4s with two Gxxx Q-RPTs, differential measurementmode is supported on the Hi Q-RPT.

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. In RPM4s with two
BGxxx Q-RPTs, differential measurement mode is supported on the Hi Q-RPT.

When changing 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 full scale is lessthan 700 kPa (100 psi), the gauge mode full scale is 100 kPa (14.5 psi) lower than theabsolute mode full scale. If the absolute mode full scale is less than 100 kPa (14.5 psi), there
is no gauge mode available. Gauge and negative gauge modes, when available, always
have the same full scale.
Measurement mode selection is range specific.
 OPERATION
See Section 3.3.3.1 for information on differential mode operation. Differential mode
operation is only available for the Hi Q-RPT in RPM4s that are equipped with two Q-RPTsof the same type (Axxx, Gxxx, BGxxx).
To change the active measurement mode for a range,press [MODE] from the MAIN RUN screen while therange is active. The display depends upon the type of
Q-RPT that is active.

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Measurement mode:
1abs 2gage 3neg gage

3. OPERATION

If an Axxx Q-RPT is active, all thee measurement modes are supported: absolute, gauge
and negative gauge. Only gauge is available if absolute and negative gauge modes havebeen turned OFF in calibration (see Section 5.2.5).
If a Gxxx Q-RPT is active, only gauge measurement mode is supported. When the [MODE]
key is pressed, <Gauge RPT, gauge mode only> is displayed.
If the Hi Q-RPT is active in its default range (<DF>), and the RPM4 has two Q-RPTs of thesame type (Axxx, Gxxx, BGxxx), differential measurement mode is available in addition to theother modes (see Section 3.3.3.1).
Certain RPM4 settings, including AutoZ ON/OFF (see Section 3.5.1) are range AND measurementmode 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 can be turned OFF in thecalibration function (see Section 5.2.5). When absolute and negative gauge mode areturned OFF for an Axxx Q-RPT, only gauge mode can be activated. <Gauge mode only,
other modes OFF> is displayed when [MODE] is pressed.

3.3.3.1

DIFFERENTIAL MEASUREMENT MODE OPERATION
Differential mode operation is only available on the Hi Q-RPT, default(<DF>) range, in RPM4s that are equipped with two Q-RPTs (Hi and Lo) of
the same type (Axxx, Gxxx, BGxxx).

To activate differential measurement mode, press [MODE] from the MAIN RUN
screen while the Hi Q-RPT is active and in its default (<DF>) range. The actual
display depends upon the measurement modes available on the Hi Q-RPT.
The cursor is on the base measurement
mode. The line pressure measurement modeis the base pressure measurement mode.

Meas mode: 1abs
2gage 3neg gage 4dif

To activate differential measurement mode, press the keypad number key for the<dif> selection or move the cursor to the <dif> selection and press [ENT].
Operation returns to the main run screen. When differential mode is active,
the cursor is on both the base mode and differential mode.
When differential mode is active, the Q-RPT position indicator is in the upper
right hand corner of the main run screen and other displays is <Hd> insteadof <Hi> (see Section 3.2.3, Table 3).

When differential mode is activated, AutoZ should be run at the line pressure
with zero differential pressure applied to eliminate the zero error on differential
pressure due to the disagreement of the Hi and Lo Q-RPTs (see Section 3.3.9.3).

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RPM4™ OPERATION AND MAINTENANCE MANUAL

The following operating conditions are specific to differential mode:
Main run screen measured pressure display
The display of measured pressure in the main run
screen is the difference between the Hi and the Lo
Q-RPTs (Hi – Lo) with a differential mode AutoZ
correction (see Section 3.3.9.3).
The pressure
measurement mode indicator is <d>. The Q-RPT
position indicator is <Hd>.

3.3.4

Default DISPLAY function

The default display function is RPT with the Lo Q-RPT
displayed on the bottom display line (see Section
3.3.6.4). This allows the line pressure (Lo Q-RPT
indication) to be viewed simultaneously with thedifferential pressure. All other DISPLAY functions(average, rate, deviation, HiLo, freeze) apply tothe differential pressure

SDS function[SDS] key operation to OPEN SDS opens SDS ofboth the Hi and Lo Q-RPTs simultaneously. (seeSection 3.3.8). Overpressure is driven by the pressure
range of the Lo Q-RPT (see Section 3.4.4.1).

AutoZ function

AutoZ manages zeroing of differential mode and isintended to “tare” the two Q-RPTs at a common
line pressure (see Section 3.3.9.3). Switch to amode other than differential for AutoZ functions ofan individual Q-RPT.

Leak Check function

The leak check function uses the differential modemeasurement (see Section 3.3.5).

Head function

The head function applies to the differential
pressure (see Section 3.3.7).

AutoRange function

Differential measurement mode is not available in
AutoRange (see Section 3.3.4).

UL function

The UL limits apply to positive and negative
differential pressure (see Section 3.4.4) and thedefault is the maximum value of the differential
pressure.
Both the Lo and Hi RPT basemeasurement mode ULs also remain active. The
Hi RPT UL provides a upper limit for the maximum
pressure on the Hi side of the differential pressure.
Both the differential and base mode Hi RPT UL
cause the display of differential pressure to flash
when exceeded. The Lo RPT UL provides anupper limit for the line pressure.

AutoTest function

The AutoTest function (see Section 3.3.10) is notavailable in differential measurement mode.

[A UTO R ANGE ] PURPOSE
To automatically set up RPM4 to optimize its measurement characteristics and features for
specific, user specified range of operation.
 PRINCIPLE
RPM4 is designed to support the calibration and test of a very wide variety of test ranges invarious measurement modes.
© 2004-2007 DH Instruments, a Fluke Company

Page 30

3. OPERATIONThe AutoRange function simplifies the task of selecting the Q-RPT best suited to cover a
specific test range and setting measurement parameters appropriately for the range. These are
set automatically based on operator entry of desired measurement mode, pressure unit of measure
and range full scale. The selections and settings made by AutoRange are summarized in Table 6.
A range set up using AutoRange and all its range specific settings, may be saved for recall
using [SETUP], <1range> (see Section 3.4.1). Saved ranges are available for later selection
using [RANGE] (see Section 3.3.1). If a range created by AutoRange is not saved, it isoverwritten by the next AutoRange or erased when another range is selected.
Press [ENT] from the main run screen in RATE mode to use the [AutoTest] function to
AutoRange RPM4 based on DUT tolerance (see Section 3.3.10).
Table 6. Settings Made by AutoRange
SETTING/SELECTIONPURPOSESET TOSECTION

Unit

Set pressure unit of measure

Operator specified during
AutoRange

3.3.2

Mode

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

Operator specified during
AutoRange

3.3.3

Full scale

Establish span maximum

Operator specified during
AutoRange

None

AutoRange span

Basis of span based setting
calculations

Absolute mode: Zero absolute
to AutoRange full scale

None

Gauge mode: Zero gauge to
AutoRange full scale
Negative gauge mode: Minus
atmosphere to AutoRange fullscale (negative equivalent of fullscale on BG15K Q-RPT).
Q-RPT

Select most appropriate Q-RPT
to cover range and mode.

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

1.2.2.1

Gauge mode: Q-RPT withlowest span whose full scale isgreater than AutoRange fullscale, Gxxx over Axxx if spansare equal.
Upper limit
Lower limit

Set maximum and minimumpressure alarm limits.

Upper limit: 105 % of operator
entered full scale pressure

3.4.4

Lower limit: None in absoluteand gauge modes. Minus
atmosphere in negative gaugemode, minus equivalent of upper
limit in negative gauge mode ona BG15K Q-RPT. Minus 66 kPa(9.6 psi) with BA100K.
Resolution

Set display resolution

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

3.4.2

Stability Limit

Set Ready/Not Ready stability
criterion.

50 ppm of AutoRange span or 2
ppm of default Q-RPT span,
whichever is larger.

3.4.3,
3.3.4

Q-RPT turn down

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

See RPM4 pressure
measurement specifications

1.2.2.1(Premium class Q-RPTs only)

Page 31© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL OPERATION
To use the AutoRange function, press [AutoRange] and respond to the RPM4’s prompts.
Select AutoRange measurement mode: The screen is identical in appearance andfunction to the [MODE] screen (see Section 3.3.3). The choice of measurement modes
offered reflects all the Q-RPT types available (Axxx, Gxxx, BGxxx) in the RPM4 system,
not just the active Q-RPT.
Differential pressure measurement mode (see Section 3.3.3.1) is not available in
AutoRange.
Select pressure unit of measure: The screen is identical in appearance and function
to the [UNIT] screen (see Section 3.3.2).
Altitude units of measure (m, ft) are not available for AutoRange.
Enter the AutoRange full scale pressure: Enter the full scale pressure value in the<------> entry field and press [ENT]. If the full scale value entered cannot be covered byany of the Q-RPTs available, an error message appears. If the full scale value can becovered, AutoRange proceeds to the range display.
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. Absolute mode only if AutoRange measurementmode is absolute and full scale is less than 100 kPa (14.5 psi).
Gauge mode only if the Q-RPT is a Gxxx or BGxxx or an Axxx
with absolute mode turned off.

AutoRange A700K
kPa
300g/100aHi

If the RPM4 has two Q-RPTs and you would like to select the other one for the
AutoRange, the cursor control keys may be used to toggle between Q-RPTs selections if
both Q-RPTs can handle the specified AutoRange.
Accept proposed AutoRange: To accept the proposed AutoRange and go to the MAIN
RUN screen with the AutoRange range active, press [ENT] or [AutoRange]. To modify
the AutoRange full scale, measurement mode or pressure unit of measure, use [ESC] toback through the AutoRange screens and make changes.
To verify or confirm the range from the MAIN RUN screen, use [+/-] or [RANGE] toview the active range (see Section 3.3.1).

See Table 6 for a listing of all selections and settings affected by AutoRange andtheir default values.

The BA100K Q-RPT cannot be AutoRanged.

© 2004-2007 DH Instruments, a Fluke Company

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3. OPERATION

3.3.5[LEAK CK] PURPOSE
To run an automated leak check routine that determines the leak rate of the system
connected to the RPM4 active Q-RPT TEST(+) port.
 PRINCIPLE
The LEAK CHECK function is provided as a means of checking and quantifying the leaks that
may be present in the system connected to the RPM4’s active Q-RPT test port.
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.
In differential pressure measurement mode (see Section 3.3.3.1), the leak checkmeasurement is based on the measurement of the differential pressure.
 OPERATION
To run a leak check, first set the pressure to the desired leak check pressure.
Changing the pressure in a test system causes adiabatic temperature changes in thepressurized medium that need to have dissipated before a valid leak measurement can be
made. In general, a 0.5 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 liquid test media, and as volume andpressure increases.
To access the LEAK CHECK function, press [LEAK CHECK] from the MAIN RUN screen.
Select <1run> to run a leak test. The display is:1.

Edit field for the time over which the leak rate will be
determined, in seconds.

Set leak check time:
15 s

Edit the leak check time if desired (minimum 1, maximum 999 seconds) and press [ENT].
Press [ENT] 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 Q-RPT position indicator3.

Indication that leak test is running and countdown of timeremaining.

Page 33

957.84 kPa a
Leak testing

Hi
13 s

© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL[ESC] can be used to abort the running leak test. [ENT] while the leak test is runningrestarts the leak check timer. When the leak check timer countdown has completed,
RPM4 beeps three times and the leak check results screen is displayed:1.

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

2.

Indicator of Q-RPT used to run the leak check.

3.

Average rate of change of pressure over the leak checktime period (∆P/time in seconds).

∆P
0.61 kPa a Hi
Rate 0.06 kPa/sec

From the leak check results screen, press [ENT] to repeat the leak test.
Press [ESC] 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 <2view>. If NO leakcheck data is stored (i.e., if the RPM4 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. Press [ENT] or [ESC] to return to the MAIN RUN screen.
Leak check is range specific in the sense that a leak check is run using the active range.
However, only one set of leak check results is maintained in memory and each leak testcompleted overwrites the memory. View leak check always shows the results of the last
leak check run regardless of the range that is now active. The results screen includes therange indicator to indicate the range in which the leak check was run.

3.3.6

[DISPLAY] PURPOSE
To select, from a variety of choices, the information that is displayed on the second line of theRPM4 display.
 PRINCIPLE
RPM4 supports a variety of advanced pressure measurement functions that are displayed on
the second (bottom) line of the RPM4 display. In summary, the available display functions
included are:
AVERAGE

Calculates the average pressure measurement over a user specified periodof time and displays the average, the standard deviation about the mean anda countdown in seconds to the next average (see Section 3.3.6.1). This function
is often used to filter out pressure noise in an unstable system. The magnitudeof the noise is quantified by the standard deviation about the mean. A second
Avg screen allows the instantaneous pressure values to be viewed during an
averaging cycle.

RATE

Calculates and displays the current rate of change of pressure in current
pressure units/second (see Section 3.3.6.2). This function is a usefulindication of the stability of the pressure being measured. It is often used as
an indication of positive or negative leak rate and as a go/no go criterion ofwhen to take data when comparing RPM4 and a device under test, forexample in a calibration. Rate is used by the Ready/Not Ready function todetermine when a Ready condition exists (see Section 3.2.1).

DEVIATION

Continuously calculates and displays the difference between the pressure
measured by RPM4 and a target pressure entered by the user (see Section
3.3.6.3). This function is useful in monitoring the evolution of pressure aroundand/or away from a desired set point.

© 2004-2007 DH Instruments, a Fluke Company

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3. OPERATION

RPT

If the RPM4 has two Q-PRTs, allows pressure measurement from the two
RPTs to be displayed simultaneously (see Section 3.3.6.4). This function isparticularly useful in dual Q-RPT RPM4s with independent TEST ports tomonitor two separate pressures simultaneously. It is also used to when the
Hi Q-RPT is in differential measurement mode, to observe the line pressure
measured by the Lo Q-RPT.

HI/LO

Records and displays maximum and minimum pressures measured (seeSection 3.3.6.5). This function is used to keep track of the minimum andmaximum pressure observed in a system over a period of time or to monitor
if a pressure min/max limit has been exceeded..

FREEZE

Captures and displays the pressure measured by the active range of RPM4
when the [ENT] key is pressed (see Section 3.3.6.6). This function is usefulto record the pressure present at the time of an operator observed trigger
event, for example when the needle of an analog gauge was on the nominal
point or when a switch activates.

CLEAN

Blanks out the second line of the display (see Section 3.3.6.7). This function
is used when a simple display of pressure measured by the RPM4 active
range without additional information is desired.

 OPERATIONTo set the DISPLAY function press [DISPLAY] from the main run screen.
1avg 2rate 3dev 4RPT
5HiLo 6freeze 7clean

The display is:

The cursor is on the active DISPLAY function. Selecting a display function returns to themain run screen with the selected function active.
Display menu choices include:<1avg>

Display average pressure and standard deviation. Specify averaging time period(see Section 3.3.6.1).

<2rate>Display pressure rate of change (see Section 3.3.6.2).

<3dev>

Display deviation of the measured pressure from a target value and specify
the target value (see Section 3.3.6.3).

<4RPT>

Display the pressure measured by the second Q-RPT in RPM4s with two
Q-RPTs (see Section 3.3.6.4).

<5HiLo>Display the maximum and minimum pressure observed since HiLo reset(see Section 3.3.6.5).

<6freeze>

Capture and display the value measured when [ENT] is pressed(see Section 3.3.6.6).

<7clean>Leave the second line of the display blank (see Section 3.3.6.7).

The DISPLAY selection is NOT range specific. A DISPLAY selection made in one range
applies to all ranges.

The default DISPLAY function is Rate which causes the second line of the display to show “R”
followed by the current rate of change of pressure in current pressure units per second.
The default DISPLAY function in differential mode is RPT.

Page 35© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

When RPM4 is initialized as an external device to a PPC3 pressure controller, the RPM4
front panel keypad is locked out and the second line of the display becomes:<PPC3 EXT DEV: IDLE><PPC3 EXT DEV: ACTIVE>(if RPM4 is initialized by PPC3 but not currently in use)
(if RPM4 is initialized by PPC3 and is currently in use)

After using an RPM4 as an external device for a PPC3, cycle power to return to theprevious RPM4 settings, restore front keypad capability and return to the normal main
run screen.

3.3.6.1

AVG (AVERAGE)

 PURPOSE
To activate the Average DISPLAY and/or adjust the period of time over which
averaging occurs.
See Section 3.3.6.  Principle.
 OPERATION
To access the Average DISPLAY, press [DISPLAY], <1Avg>. The display is:1.

Edit field for averaging period in seconds.
Default is 20. Minimum 1, maximum 999.

Averaging Period:
20 s

Edit the averaging time period if desired. Pressing [ENT] returns to the main run
screen with the Average DISPLAY active.
With the Average DISPLAY active the main run screen is:
1.

Average measured
averaging period.

over

last

completed

2.

Standard deviation
averaging period.

of

last

completed

3.

Countdown in seconds until completion of ongoing averaging period.

96.929 kPa a
Hi
δ 0.0007
18Avg

The Average DISPLAY has a second screen that allows the instantaneouspressure readings to be viewed while an averaging cycle is running.
The instantaneous Average screen is:1.

Instantaneous pressure values at RPM4’s
normal update rate.

2.

Current rate of change of pressure in pressure
units/second.

3.

Countdown in seconds until completion of ongoing averaging period.

96.929 kPa a
Hi
R 0.0025
18Avg

The [+/-] key toggles between the main run Average screen and theinstantaneous values Average screen.

© 2004-2007 DH Instruments, a Fluke Company

Page 36

3. OPERATION

Pressing [ENT] while in the Average DISPLAY aborts the current averaging
period and causes a new one to begin. [ENT] can thus be use to trigger a
new averaging period on demand.

In the Average DISPLAY the Ready/Not Ready indication applies to the resultof the previous averaging period (see Section 3.2.1). <Ready> indicates that
all readings during the previous averaging period met the stability criterion.
<Not Ready> indicates that one or more readings were outside of thestability criterion.

Changing the pressure unit of measure, measurement mode or range while
the averaging screen is active, starts a new averaging period.

To go to a DISPLAY other than Average, press [DISPLAY] and make a new
DISPLAY choice (see Section 3.3.6).

3.3.6.2

Rate

 PURPOSE
To activate the Rate DISPLAY.
See Section 3.3.6 [DISPLAY],  Principle.

The AutoTest function (see Section 3.3.10) to AutoRange RPM4 based on
DUT characteristics and run an automated test sequence is accessed bypressing [ENT] from the Rate run screen.
 OPERATION
To activate the Rate DISPLAY press [DISPLAY], <2Rate>. Pressing <2Rate>
returns to the main run screen with the Rate DISPLAY active.
With the Rate DISPLAY active the main run screen is:1.

Current rate of change of pressure in current
pressure units per second.

99.1135 psi a
R 0.0001/sec

Hi

The Rate DISPLAY is different and separate from the stability setting which
is used to set the stability criterion on which the Ready/Not Ready
indication is based (see Sections 3.4.3 and 3.2.1). The Rate DISPLAY only
causes the current rate of change to be displayed and has NO affect on thestability setting or the Ready/Not Ready condition.

Page 37© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUALThe Rate DISPLAY is the default display except in differential measurementmode in which the default DISPLAY is RPT.

To go to a DISPLAY other than Rate, press [DISPLAY] and make a new
DISPLAY choice (see Section 3.3.6).

3.3.6.3

Dev (Deviation)

 PURPOSE
To activate the Deviation DISPLAY and/or set the deviation target value.
See Section 3.3.6 [DISPLAY],  Principle.
 OPERATION
To activate the Deviation DISPLAY press[DISPLAY], <3Dev>. The display is:

Target:100.0000 psi a

Edit the desired target value. Pressing [ENT] returns to the main run screen with
the Deviation DISPLAY active using the entered target value.
The target value is the value from which deviations (D) are measured by theDeviation DISPLAY following:D = current pressure - target pressureWith the Deviation DISPLAY active the main run screen is:1.

Deviation of current pressure from the target
value.

2.

Target value.

99.1135 psi a zH3
D -0.8865 T100.0000

Pressing [ENT] from the main run screen when the Deviation DISPLAY is
active goes directly to the Target editing screen. This allows the target
value to be changed without going through the DISPLAY menu.

If the pressure measurement unit or mode is changed while the Deviation
DISPLAY is active the target value remains at the same numerical value.
It is NOT converted.

To go to a DISPLAY other than Deviation, press [DISPLAY] and make a new
DISPLAY choice (see Section 3.3.6).

© 2004-2007 DH Instruments, a Fluke Company

Page 38

3. OPERATION

3.3.6.4

RPT

 PURPOSE
To activate the RPT DISPLAY.
See Section 3.3.6,  Principle.

The RPT DISPLAY is only available in RPM4s with two Q-RPTs.
 OPERATION
For the sake of clarity, when describing the RPT DISPLAY, the Q-RPT
displayed on the top line of the display when the RPT function is selected isreferred to as the “active” Q-RPT. The other Q-RPT to be displayed on thesecond (bottom) line of the RPM4 display is referred to as the “inactive”
Q-RPT. It is “inactive” in the sense that all RPM4 functions and settings
such as UNIT and RES still apply to the “active” Q-RPT. To make changes tothe “inactive” Q-RPT, for example to change its measurement units, it must
be made the active Q-RPT by a conventional range change (see Section 3.3.1).
In differential pressure measurement mode, the Hi Q-RPT is always the“active” Q-RPT.
To activate the RPT DISPLAY, press [DISPLAY], <4RPT>. Operation returns to
the MAIN RUN screen with the inactive Q-RPT displayed on the display’s bottom
line. The range of the inactive Q-RPT is always the default range, not an
AutoRanged range (see Section 3.3.4).
If the RPM4 has only one Q-RPT, <Not available with single RPT> displays
momentarily and operation returns to the main run screen when [DISPLAY],<4RPT> is pressed.

If the RPM4 is in parallel (<HL>) (see Section 3.5.7.3) mode in which both
Q-RPTs are used simultaneously, when <4RPT> is selected, the Q-RPT to display
on the lower display line must be specified. The Q-RPT specific settings of the
Q-RPT displayed in the lower display line (measurement mode, unit of measure,resolution, etc.) can only be changed by making that Q-RPT active.
With the RPT DISPLAY active the main run screen is:1.

Active RPT display.

2.

Inactive RPT display with Ready/Not Ready
indicator on far left.

Page 3999.1135 psi a*2350.23 psi g

zHi
zLo

© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

If the inactive RPT is equipped with SDS Self Defense System (see Section
3.2.7), SDS will almost certainly be CLOSED when the RPT DISPLAY is activated.
SDS can be OPENED on the inactive RPT using [SPECIAL], <4SDS> (see Section
3.5.4). In differential or parallel measurement mode, SDS can be opened
simultaneously on both Q-RPTs using [SDS] (see Section 3.3.8).

The RPT DISPLAY is the default display in differential measurement mode.

When the RPT display is active, executing a range change to a range on theinactive Q-RPT makes the inactive Q-RPT the active Q-RPT. The DISPLAY
defaults back to Rate ( Section 3.3.6.2).

To go to a DISPLAY other than RPT, press [DISPLAY] and make a new
DISPLAY choice (see Section 3.3.6).

3.3.6.5

Hi/Lo PURPOSE
To activate the Hi/Lo DISPLAY.
See Section 3.3.6,  Principle..
 OPERATION
To activate the Hi/Lo DISPLAY press [DISPLAY], <5Hi/Lo>. Pressing <5Hi/Lo>
resets the Hi/Lo values and returns to the main run screen with the Hi/LoDISPLAY active.
With the Hi/Lo DISPLAY active the main run screen is:1.

Highest pressure observed since Hi/Lo reset.

2.

Lowest pressure observed since Hi/Lo reset.

99.1135 psi a zHi
H 99.2254 L98.0098

The Hi/Lo values change each time a new Hi or Lo pressure is observed.
The Hi/Lo record can be reset at any time by pressing [ENT]. This allows a
Hi/Lo reset without going back through the DISPLAY menu.

If the pressure measurement unit, mode or range is changed while the Hi/LoDISPLAY is active, Hi/Lo resets.

To go to a DISPLAY other than Hi/Lo, press [DISPLAY] and make a new
DISPLAY choice (see Section 3.3.6).

© 2004-2007 DH Instruments, a Fluke Company

Page 40

3. OPERATION

3.3.6.6

Freeze PURPOSE
To activate the Freeze DISPLAY.
See Section 3.3.6,  Principle.
 OPERATION
To activate the Freeze DISPLAY press [DISPLAY], <6Freeze>. Pressing<6Freeze> returns to the main run screen with the Freeze DISPLAY active.
With the Freeze DISPLAY active the main run screen is:1.

Pressure measured by active range of RPM4
when [ENT] was pressed (displays 0.00 by
default when Freeze DISPLAY is firstactivated).

99.135 psi a
F 99.2133

zHi

Pressing [ENT] causes the current pressure measured by the active RPM4 Q-RPT
to be captured and displayed.
If the pressure measurement unit, mode or range is changed while the Freeze
DISPLAY is active, the Freeze value defaults back to zero.

To go to a DISPLAY other than Freeze, press [DISPLAY] and make a new
DISPLAY choice (see Section 3.3.6).

3.3.6.7

Clean

 PURPOSE
To activate the Clean DISPLAY.
See Section 3.3.6,  Principle..

The AutoTest function (see Section 3.3.10) to AutoRange RPM4 based on
DUT characteristics and run an automated test sequence is accessed bypressing [ENT] from the Rate run screen.

Page 41© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL OPERATION
To activate the Clean DISPLAY press [DISPLAY], <7Clean>. Pressing <7Clean>
returns to the main run screen with the Clean DISPLAY active.
With the Clean DISPLAY active the main run screen is:1.

Conventional main run screen first line.

2.

“Clean” second line.

99.135 psi azHi

To go to a DISPLAY other than Clean, press [DISPLAY] and make a new
DISPLAY choice (see Section 3.3.6).

3.3.7[HEAD]

 PURPOSE
To cause a pressure fluid head correction to be added to or subtracted from the pressure
measured by the RPM4 reference pressure transducer in order to predict the pressure at aheight other than the RPM4’s reference level.
 PRINCIPLE
RPM4 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 RPM4’s TEST(+) port. This difference in height, frequently called
head, can cause a significant difference between the pressure measured by the RPM4 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 RPM4 in order to predict the pressure actually applied at a different height.
RPM4 can accurately determine “head” pressures for gases (nitrogen, helium and air) andliquids (oil, water) as the pressurized medium. In calculating the head value, standard gravity(9.80665 m/s2) is used. Gas densities are calculated from the selected gas’s standard
density correcting for temperature of 20°C and the measured pressure using the gas’s
compressibility factor to 100 MPa (15 000 psi) and extrapolated above 100 MPa. Oil density
is taken to be 850 kg/m3, the density of typical calibration oils at 20°C. Water density is taken
to be 998.2321kg/m3 (20°C). A custom liquid density may also be specified.
The [HEAD] function key is used to specify the height difference between the RPM4 TEST(+)
port and another height. Entering a height of zero turns the function off. The height unit andthe test fluid are specified by pressing [SPECIAL], <3Head> (see Section 3.5.3).
Use of the HEAD function to assure in tolerance measurements is most important in low
absolute pressure ranges. Specifying the head height within ± 5 cm (2.5 in.) is adequate
to assure that, even in the worst case, the uncertainty on the head correction will beinsignificant relative to the tolerance on the measurement.

© 2004-2007 DH Instruments, a Fluke Company

Page 42

3. OPERATION

 OPERATION
To access the HEAD function, press [HEAD]. The display is:1.

Test fluid currently specified for the head correction.

2.

Edit field for head height.

Edit head height:
+ 25
cm
N2

Edit the head height to the desired value. Press [ENT] to return to the MAIN RUN screenwith the new head correction active. Press [ESC] to return with no changes.
The reference height of the RPM4
pressure measurement is the middle of
the RPM4 TEST port. The head heightshould be entered as a positive value if
the device or system under test is
higher than the RPM4 and negative if it
is lower.
The HEAD function is NOT range specific. The HEAD ON or OFF status remains the sameas Q-RPTs and ranges are changed. Edits made to the head settings are independent ofactive range or Q-RPT.

When a head correction is being applied, it is indicated by <h> in the top line of the MAIN
RUN screen (see Section 3.1.1). When the head correction is zero, the <h> is not shown.

To change units of head height between inches and centimeters and to change the test
fluid species, use [SPECIAL], <3head> (see Section 3.5.3).

3.3.8[SDS] (SELF DEFENSE SYSTEM)

 PURPOSE
To CLOSE SDS on all reference pressure transducers (Q-RPTs). To OPEN SDS on theactive Q-RPT.
SDS is present only on Q-RPTs designated A7M or lower.

The [SDS] key should be used with care to avoid accidentally overpressuring a Q-RPT.
Always double check to ensure that the pressure applied to the Q-RPT’s TEST port islower than the Q-RPT’s maximum pressure before OPENING SDS.

SDS can be set to permanently be OPEN as if no SDS were installed (see Section
3.5.4.2).

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RPM4™ OPERATION AND MAINTENANCE MANUAL PRINCIPLE
SDS is a self defense system to protect RPM4 Q-RPTs from overpressure. SDS CLOSES
automatically to protect a Q-RPT that is not active. In a two Q-RPT RPM4, activating one
Q-RPT automatically CLOSES SDS on the other Q-RPT. Powering down the RPM4 orenergizing it also CLOSES SDS on all Q-RPTs.
When a Q-RPT’s module’s SDS is CLOSED, the Q-RPT is isolated from the TEST(+) port
and opened to the VENT port. SDS must be OPENED for the pressure applied to the
TEST(+) port to be measured. The [SDS] key is used to OPEN SDS.
The SDS function can also be used to CLOSE SDS as might be desired when leaving RPM4
at rest or when a possible overpressure situation is anticipated. Pressing [SDS] always
CLOSES any SDS systems that are OPEN.
See Section 3.2.7 for general information on SDS and its principles and Section 5.6,
Figure 8 for Q-RPT module schematics.

SDS closed is indicated by <SDS CLOSED> flashing in the current measured pressure
display field. When SDS is closed, the Q-RPT is isolated from the TEST(+) port andconnected to the VENT port.
 OPERATION
Though the SDS self defense system includes features to protect Q-RPTs against
overpressure, SDS should NOT be considered a fail-safe overpressure protection system.
SDS cannot guarantee that overpressure damage will NOT occur. SDS closing automaticallymay protect an RPT in case of accidental overpressure but conventional measures foroverpressure protection should always be used. Damage to Q-RPTs due to overpressure
is NOT covered by the RPM4 product warranty even when SDS is present and ON.

The maximum pressure that should be applied to an RPM4 TEST(+) port when SDS is
CLOSED is 10 MPa (1 500 psi).

When SDS is CLOSED with a pressure applied, a valve shuts isolating the Q-RPT from the
TEST(+) port. Another valve vents the Q-RPT to atmosphere through the VENT port.
If the pressure applied at the time SDS is CLOSED is less than 1 700 kPa (250 psi),the VENT valve will open causing sudden release of pressure through the VENT port andreturning the Q-RPT to atmospheric pressure. If the pressure applied at the time SDS is
CLOSED is greater than 1 700 kPa, the VENT valve may NOT open. In this case, to ventpressure from the Q-RPT module, remove the pressure from the TEST(+) port. This willcause the SDS TEST port isolation valve to open partially, reducing pressure under
1 700 kPa at which time the SDS VENT valve will open (see Section 5.6, Figure 8)

Pressing [SDS] always CLOSES any SDS system that is OPEN. In a dual Q-RPT RPM4,
even if the active Q-RPT has NO SDS, pressing [SDS] CLOSES SDS for the inactive Q-RPT
if SDS is present.

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3. OPERATION

Use [SDS] to OPEN SDS if it is CLOSED for the active Q-RPT and/or to CLOSE SDS for theactive and inactive Q-RPT.
When [SDS] is pressed, there are three possible results depending whether the active Q-RPT is
SDS equipped and ON (see Section 3.5.4.2), and whether its SDS is OPEN or CLOSED.
1. If the active Q-RPT IS NOT SDS equipped or its SDS if “full time OFF” (see Section 3.5.4.2):<No SDS on RPT> or <SDS is OFF and OPEN> is displayed for 5 seconds andoperation returns to the main run screen. If there is a second Q-RPT with SDS, its SDS
is CLOSED.
2. If the active RPT IS SDS EQUIPPED and SDS on the active RPT is OPEN:
SDS is CLOSED and operation returns to the main run screen.
3. If the active RPT IS SDS EQUIPPED and SDS on the active RPT is CLOSED:The OPEN SDS routine is presented. The display is :1.

Maximum acceptable pressure of active Q-RPT (always
absolute on an Axxx Q-RPT and gauge on a Gxxx Q-RPT).

2.

Position designator of Q-RPT for which SDS will be
opened.

Pmax! 350 kPa a Hi
Open SDS?
1no 2yes

Check that the pressure applied to the TEST(+) port does NOT exceed the maximum
acceptable value for the Q-RPT. Select <1no> to return to the main run screen without
OPENING SDS, select <2yes> to OPEN SDS and return to the main run screen withSDS OPEN (the active Q-RPT open to the TEST(+) port).
Opening SDS with a pressure greater than Pmax! applied to the test port may cause
overpressure damage to the Q-RPT.

In differential and parallel measurement modes, opening SDS acts simultaneously on
BOTH THE Hi AND Lo Q-RPTs (see Section 3.3.8.1). The Pmax! pressure is the Lo RPT.
Be sure to check BOTH Q-RPT TEST(+) ports are at a safe pressure before opening SDS.

The [SDS] key is also the [2] key which is pressed to select <2Yes> to OPEN SDS.
Thus, SDS can be OPENED by two rapid presses of [SDS]. Use this feature toconveniently OPEN SDS but always check that the pressure connected the TEST(+) port
does NOT exceed Pmax! before doing so.

When changing ranges causes a change of active Q-RPT, SDS is automatically CLOSED for
the Q-RPT that is being changed from, leaving the inactive Q-RPT with SDS CLOSED.

The Lo and Hi Q-RPTs’ SDS, if present, can be controlled directly regardless of which
Q-RPT is currently active (see Section 3.5.4).

SDS can be permanently opened so operation is as if SDS were not present(see Section 3.5.4.2).

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3.3.8.1

SDS IN DIFFERENTIAL AND PARALLEL MEASUREMENTMODES
In differential and parallel measurement modes, opening SDS opens SDS for
BOTH the Hi and Lo Q-RPTs. Before opening SDS, be certain that thepressure applied to both the Hi and Lo RPM4 TEST(+) ports is less than the
maximum pressure of the Lo Q-RPT.

Differential (see Section 3.3.3.1) and parallel measurement modes (see Section
3.5.7.3) use two Q-RPTs in one RPM4 to simultaneously. In these modes,
function of the [SDS] key is adapted to facilitate operation using both Q-RPTs
simultaneously. [SDS] can be used to OPEN SDS on both the active an inactive
Q-RPTs at the same time.
Pressing [SDS] always CLOSES any ON and OPEN SDS, as it does in single Q-RPT
mode operation. However, if SDS is CLOSED for any and all modules equippedwith SDS, pressing SDS goes to the usual OPEN SDS routine which will OPEN
SDS for both Q-RPTs.
The display is :1.

Maximum acceptable pressure of the Lo
Q-RPT (always absolute on an Axxx Q-RPT
and gauge on a Gxxx Q-RPT).

2.

Position designator of active Q-RPT. <HL> inparallel mode, <Hd> in differential mode.

Pmax! 350 kPa a HLOpen Hi&Lo? 1no 2yesCheck that the pressure applied to BOTH the TEST(+) ports does NOT exceed
the maximum acceptable value for the Lo Q-RPT. Select <1no> to return to themain run screen without OPENING SDS, select <2yes> to OPEN SDS for both
Q-RPTs and return to the main run screen with SDS OPEN (the active Q-RPT
open to the TEST(+) port).

3.3.9[A UTO Z]

 PURPOSE
To run the AutoZ function that rezeros the active Q-RPT between full calibrations.
See Section 3.5.1,  Principle for a full explanation of the AutoZ function.
 PRINCIPLE
Run AutoZ is the function by which the current Q-RPT reading is compared to a reference,
Pstd,0, at atmospheric pressure to determine a new value of Poffset. The value of Poffset is thenused by AutoZ to automatically correct the Q-RPT for possible changes in zero over time(see Section 3.5.1,  PRINCIPLE).
Running AutoZ in parallel mode (see Section 3.5.7.3) autozeros the Hi and Lo Q-RPTs
simultaneously and independently. There is are no Zoffset values specific to the HL QRPT.
See Section 3.3.9 to run AutoZ.

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3. OPERATION

3.3.9.1[AUTOZ] IN GAUGE AND NEGATIVE GAUGE MODE

 PURPOSE
To “rezero” the active Q-RPT in gauge measurement mode.
See Section 3.5.1,  Principle for a full explanation of the AutoZ function.
 OPERATION
For the AutoZ function key to run AutoZ, AutoZ must be turned ON for theactive range and measurement mode. AutoZ ON is indicated by <z> to theleft of the Q-RPT designator on the first line of the main run screen. AutoZ
ON and OFF is set using [SPECIAL], <1AutoZ> (see Section 3.5.1). If AutoZ
is OFF for the active Q-RPT, and measurement mode, <AutoZ is off >is displayed when [AutoZ] is pressed.

Running AutoZ in or parallel mode (see Section 3.5.7.3) autozeros both the
Hi and Lo Q-RPTs simultaneously.
To run AutoZ in gauge measurement mode, set gauge or negative gauge as themeasurement mode (see Section 3.3.3) and press [AutoZ] from the main run
screen. If the Q-RPT is a Gxxx or BGxxx type, the display is <Preparing to
AutoZ> for five seconds to allow time for the bypass valve between the TEST(+)
and TEST(-) sides of the Q-RPT to assure zero differential pressure and for thepressure to stabilize (see Section 5.6, Figure 8). <Running gauge AutoZ> isdisplayed briefly before returning to the main run screen.
Before running AutoZ in gauge mode, ensure that the pressure applied to
the Q-RPT is truly zero gauge (atmospheric pressure). If running AutoZ ingauge mode results in a zero offset that RPM4 considers unusually large,<Confirm 0 gauge P!> is displayed when AutoZ is pressed. Check that zerogauge pressure is applied to the TEST(+) port and there is no differential
pressure across the TEST(+) and TEST(-) ports and press ENTER tocontinue or ESCAPE to abort.

Allow the RPM4 to stabilize at atmospheric pressure and ambient
temperature for 1 to 2 minutes before running AutoZ in gauge mode.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

3.3.9.2[AUTOZ] IN ABSOLUTE MODE

 PURPOSE
To “rezero” the active Q-RPT in absolute measurement mode
See Section 3.5.1,  Principle for a full explanation of the AutoZ function.
 OPERATION
For the AutoZ function key to run AutoZ, AutoZ must be turned ON for theactive Q-RPT and measurement mode. AutoZ ON is indicated by <z> to theleft of the range designator on the first line of the main run screen. AutoZ
ON and OFF is set using [SPECIAL], <1AutoZ> (see Section 3.5.1). If AutoZ
is OFF for the active range, and measurement mode, <AutoZ OFF> isdisplayed when [AutoZ] is pressed.

Running AutoZ in or parallel mode (see Section 3.5.7.3) autozeros both the
Hi and Lo Q-RPTs simultaneously.
To run AutoZ in absolute measurement mode, set absolute measurement mode(see Section 3.3.3) and press [AutoZ] from the main run screen. The display is:1.

Active Q-RPT designator.

2.

Current measurement mode (absolute).

3.

Selection of source of Pstd,0 reference to whichto AutoZ.

AutoZ Hi abs by:
1Entry 2COM2 3Lo RPT

Selecting <1Entry> allows the value of Pstd,0 to be entered from the front panel keypad.
Selecting <2COM2> allows the value of Pstd,0 to be read automatically from another
DHI RPMx connected to RPM4’s COM2 communications port.
Selecting <3Lo RPT> is shown only if the active Q-RPT is Hi and there is a Lo
Axxx Q-RPT in the RPM4. This selection allows the value of Pstd,0 for the Hi
Q-RPT to be read automatically from the RPM4s Lo Q-RPT.
Allow the RPM4 to stabilize at atmospheric pressure and ambient
temperature for 10 to 15 minutes before running AutoZ in absolute mode.

If running AutoZ results in a value of Poffset that is greater than ± 0.005 % FS of
the span of the Q-RPT that is being AutoZeroed, the Q-RPT and/or the reference
used as the source 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 good working order, properly vented to stable atmospheric pressure,at the same height, and reading in the same pressure units when AutoZ was run.

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3. OPERATION

When the run AutoZ selection is made, if a HEAD correction is currently active(see Section 3.3.7) the head correction is momentarily disabled while running
AutoZ to avoid “zeroing out” the head value.

The value of Poffset is always displayed and entered in Pascal (Pa).
Run AutoZ by Entry
AutoZ by entry allows the value of Pstd,0 (see Section 3.5.1,  PRINCIPLE) to beentered directly from the RPM4 front panel. This provides a simple way of
AutoZeroing relative to an independent reference device such as a housebarometer that does not interface directly with RPM4.
To access run AutoZ by entry press [AutoZ], <1entry>. The display is:1.

Real time pressure reading (without headcorrection), pressure unit of measure andmeasurement mode 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
Pstd,0:0.00000

Hi

Enter the value of the AutoZ reference (Pstd,0) in the same unit of measure as the
top line display and press [ENT]. RPM4 logs the reading and calculates a new
AutoZ offset value. The next display is:
Press [ENT] to activate the new value ofPoffset or [ESC] to start over with entry of a
new AutoZ reference (Pstd,0) value.

Old Poffset: 0.0 Pa
New Poffset: 8.3 Pa

The value of Poffset is always in Pascal (Pa). The value of Pstd,0 is entered in
the current pressure unit of measure.
Run AutoZ by COM2
AutoZ by COM2 allows the value of Pstd,0 (see Section 3.5.1  Principle) to be read
automatically from a DHI RPMx connected to the RPM4 COM2 communications
port. The RPMx is read and the new Poffset is calculated automatically.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

To access run AutoZ by COM2 press [AutoZ], <2COM2>. The display is:1.

Real time pressure reading (without headcorrection), pressure unit of measure andmeasurement mode of the active Q-RPT.

2.

Active Q-RPT position designator.

3.

Real time reading from the RPMx connected
to RPM4’s COM2 communications port.

96.7755 kPa a
Pstd,0:0.00000

Hi

Observe the displayed pressures and verify that they are stable. When ready,press [ENT] to cause AutoZ to run. RPM4 logs both readings and calculates a
new AutoZ offset value. The display is:
Press [ENT] to activate the new value ofPoffset or [ESC] to start over.

Old Poffset: 0.0 Pa
New Poffset: 3.1 Pa

For RPM4 to communicate with an RPMx connected to its COM2 port, theRPM4 and the RPMx RS-232 interfaces must be set up properly(see Section 3.5.2). If, the RPM4 is unable to communicate with an RPMx via
COM2 when running AutoZ by COM2, it times out after 6 seconds anddisplays <RPM NOT detected>.

The value of Poffset is always displayed and entered in Pascal (Pa).
Run AutoZ by Lo RPT
AutoZ by Lo RPT is available only if the active Q-RPT is the Hi Q-RPT and there
is an Axxx Lo Q-RPT. AutoZ by Lo RPT allows the Lo Q-RPT in an RPM4 to serveas the AutoZ reference (source of Pstd,0) (see Section 3.5.1,  PRINCIPLE).
The Lo Q-RPT is read and the new Poffset is calculated automatically.
To access run AutoZ by Lo RPT press [AutoZ], <3Lo RPT>. The display is:1.

Real time pressure reading (without headcorrection), pressure unit of measure andmeasurement mode of the active Q-RPT.

2.

Active Q-RPT position designator.

3.

Real time reading from the Lo Q-RPT.

96.7755 kPa a
Pstd,0:97.7786

Hi

Observe the displayed pressures and verify that they are stable. When ready,press [ENT] to cause AutoZ to run. RPM4 logs both readings and calculates a
new AutoZ offset value. The display is:
Press [ENT] to activate the new value ofPoffset or [ESC] to start over.

Old Poffset: 0.0 Pa
New Poffset: 3.1 Pa

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

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3. OPERATION

3.3.9.3

AUTOZ IN DIFFERENTIAL MODE

 PURPOSE
To compensate for the offset between the Hi Q-RPT and the Lo Q-RPT at theoperating “line pressure” in differential measurement mode.
See Section 3.5.1,  Principle for a full explanation of the AutoZ function.


OPERATION
For the AutoZ function key to run AutoZ, AutoZ must be turned ON for theactive range and measurement mode. AutoZ ON is indicated by <z> to theleft of the Q-RPT designator on the first line of the main run screen. AutoZ
ON and OFF is set using [SPECIAL], <1AutoZ> (see Section 3.5.1). If AutoZ
is OFF for the active Q-RPT, and measurement mode, <AutoZ is off > isdisplayed when [AutoZ] is pressed.

To run AutoZ in differential measurement mode, set differential as themeasurement mode (see Section 3.3.3) and press [AutoZ] from the main run
screen. <Running differential AutoZ> is displayed briefly before returning to themain run screen.
Before running AutoZ in differential mode, set the “line pressure” at which
the differential measurements will be made and assure that a commonpressure is applied to both Q-RPTs. If running AutoZ in differential mode
results in a zero offset that RPM4 considers unusually large, <Confirm 0
DP> is displayed when AutoZ is pressed. Check that zero differential
pressure is applied across the Hi and Lo TEST(+) ports and press ENTER tocontinue or ESCAPE to abort.

Allow the RPM4 to stabilize at atmospheric pressure and ambient
temperature for 2 to 3 minutes before running AutoZ in differential mode.

3.3.10[ENT] (RUN AUTOTEST) PURPOSE
To run the AutoTest function which AutoRanges the RPM4 and runs a calibration test basedon user entries of pressure unit, measurement mode, full scale, increment and DUT
tolerance.
Run AutoTest is accessed by pressing [ENT] from the Rate or Clean DISPLAY mode (seeSection 3.3.6.2). In other DISPLAY modes, the function of [ENT] is specific to the mode.

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RPM4™ OPERATION AND MAINTENANCE MANUAL PRINCIPLEThis feature not available at the time of release of this manual. Check www.dhinstruments.com
for new RPM4 embedded software releases and manual updates.
 OPERATION
Feature not available at the time of release of this manual.

3.4[SETUP] PURPOSE[SETUP] accesses a menu of functions and features commonly used in setting up and using RPM4.
 OPERATION
To access the SETUP menu, press [SETUP] from the MAIN RUN
screen. The display is:

1range 2res 3stab
4UL 5ATest

SETUP menu choices include:<1range>

Save and delete ranges created by AutoRange (see Section 3.4.1).

<2res>

Adjust the resolution of pressure displays (see Section 3.4.2).

<3stab>Adjust the pressure stability test that is the criterion for the Ready/Not Ready indication(see Section 3.3.3).

<4UL>

Adjust upper and lower pressure limit alarms (see Section 3.4.4).

<5ATest>View data files resulting from running QDUT AutoTests (See Section 3.4.5).

3.4.1<1RANGE> PURPOSE
Save AutoRange ranges and associated settings for recall. Delete previously saved AutoRange ranges.
 PRINCIPLEThe RPM4 AutoRange function creates a range and automatically sets various operating
parameters proportionally to the range (see Section 3.3.4). Operating settings can then bechanged by the user. Many operating settings are specific to the current range (see Table 4).
[SPECIAL], <1range> allows the AutoRange range and associated settings to be saved forrecall using the [RANGE] key (see Section 3.3.1). This can avoid having to recreate
frequently used ranges and settings.
[SPECIAL], <1range> is also used to delete ranges that have been saved but are no longer needed.

3.4.1.1


SAVING AN A UTO R ANGE RANGEOPERATION

To save a range created by AutoRange, the range must be the active range.
Use AutoRange to create the range (see Section 3.3.4) and then make any
desired feature and setting adjustments.

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3. OPERATION

Once the AutoRange range is set up as desired, press [SETUP], <1range>,<1save>. The display is:1.

Indication that this is a range to be 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.

Save range A700K
kPa
300g/100a

Hi

Press [ENT] to save the range or [ESC] to return to the MAIN RUN screen without
saving the range.
Default (<DF>) Q-RPT ranges cannot be saved. They are permanent.
Duplicate AutoRange ranges cannot be saved. A duplicate AutoRange range
is a range that has the same measurement mode and full scale and uses thesame Q-RPT as a range that has already been saved.

3.4.1.2


DELETING A UTO R ANGE RANGESOPERATION

To delete a single saved AutoRange range, press [SETUP], <1range>, <2delete>.
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 Hi
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, press [ENT]. If you are sure youwant to delete this range, press [ENT] again in response to the <Delete?> query.
[ESC] returns to the <AutoRange:> screen without deleting a range.
To delete all of the saved AutoRange ranges, press [SETUP], <1range>,<3delete all>. If you are sure you want to delete all the ranges, respond <1yes>to the <Delete all saved ranges?> query. If not, respond <2no>.

3.4.2<2RES> (RESOLUTION)

 PURPOSE
To set the resolution with which measured pressures and other pressure indications andsettings are displayed.
 PRINCIPLE
The resolution with which RPM4 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 span of the range and then rounded to the furthest
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RPM4™ OPERATION AND MAINTENANCE MANUAL

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.
Default resolution is 10 ppm of active range span. Resolution is set automatically by
AutoRange (see Section 3.3.4).
 OPERATION
To access the resolution function, press [SETUP],<2res>. The display is:

Display resltn:
Hi0.0010 %FS< and >

Use the cursor control keys to set the desired level of resolution. Press [ENT] to return to the
MAIN RUN screen with the new resolution setting active or [ESC] to make no changes.
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.

3.4.3<3STAB> PURPOSE
To view and/or adjust the stability test that is the Ready/Not Ready criterion for the active
RPT and range.
See Section 3.2.1 Pressure Ready/Not Ready Indication.
 PRINCIPLE
RPM4 continuously monitors the rate of change of pressure measured by the active RPT andrange and compares this rate to the stability limit to make a Ready/Not Ready determination(see Section 3.2.1 Pressure Ready/Not Ready Indication). The stability function allows thestability limit to be adjusted by the user to increase or decrease the stability required for a
Ready condition to occur.
The default stability limit is + 0.005% FS of the active range.

The stability limit is separate and different from the Rate DISPLAY function (see Section
3.3.6.2) which allows the current rate of change of pressure to be displayed.

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3. OPERATION

 OPERATION
To access the stability setting adjustment, press[SETUP], <3stab>. The display is:

Stability:
0.020 Pa

Hi

Edit the desired stability limit setting if desired. [ENT] activates the stability limit for the active
range and returns to the main run screen Press [ESC] to return to the MAIN RUN screenwith no change to the stability limit.
The stability setting is range specific. A stability setting made in one range does NOT
affect other ranges.

3.4.4<4UL> (UPPER LIMIT) PURPOSE
To set the upper and lower pressure limit values for a pressure range and measurement mode.
 PRINCIPLEThe UPPER LIMIT function provides the user with settable pressure limits at which an alarmsounds. Absolute and gauge measurement modes (see Section 3.3.3,  PRINCIPLE) haveupper limits only. Negative gauge mode and the BA100K also have a lower limit.
When the limit is reached, RPM4’s beeper sounds intermittently as long as pressure isoutside the limit.
The UPPER LIMIT function has two purposes. First, when UL is set to its default value, it serves
as a warning that the maximum pressure of the active range (and lower pressure in negative
gauge mode) is about to be exceeded. Second, UL can be set by the user to a value otherthan the default value to provide an alarm that a specific pressure limit has been exceeded.
This feature is often used to help protect an external device or system on which RPM4 isbeing used to measure pressure. For example, it might be set just over the full scale of adevice under test (DUT) that is being calibrated. Note that using AutoRange automaticallysets the UL to just above the AutoRange full scale (see Section 3.3.4).
The default upper limit is 105 % of AutoRange span or 102 % of Q-RPT default (maximum)
range, whichever is lower. The default lower limit (negative gauge mode only ) is – 110 kPa(- 16 psi), except with the BG15K Q-RPT in which the default lower limit is the negativeequivalent of the upper limit. The default lower limit of the BA100K Q-RPT is 66 kPa (9.6 psi).

In parallel measurement mode (see Section 3.5.7.2), the default and maximum UL is the
UL of the Lo Q-RPT.
In differential measurement mode (see Section 3.3.3.1), UL has upper and lower limits.
The default upper differential UL is the maximum pressure of the Hi Q-RTP. The default lower
UL is the negative value of the upper limit.
In differential measurement mode, the ULs on the Lo Q-RPT and Hi Q-RPT default range arealso active so that line pressure (Lo Q-RPT) and total pressure (Hi Q-RPT) upper limit can be
set and monitored in addition to a differential limit.

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RPM4™ OPERATION AND MAINTENANCE MANUAL OPERATION
To view or edit upper and lower limits press [SETUP], <4UL>.
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

Hi

Edit the upper limit value as desired. The maximum upper limit is 105 % of span in an
AutoRange range or 102 % of default Q-RPT full scale, whichever is smaller. Press [ENT] toreturn to the MAIN RUN screen with the new upper limit active. Press [ESC] to return to the
MAIN RUN screen with no change to the upper limit.
If the current measurement mode is negative gauge, there is an upper limit and a lower 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

Hi
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. Press [ENT] to returnto the MAIN RUN screen with the new upper and/or lower limit active. Press [ESC] to returnto 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 on/2 seconds off intervals. Change the pressure applied
to RPM4 so that it is within the upper and/or lower limit to return to normal operation.
Upper limit values are specific to each range and measurement mode. Be careful not toassume that the upper limit set in one measurement mode will apply to the other.
For example, if you change the upper limit in gauge mode, the upper limit will not bechanged in negative gauge mode.

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 altitudeunit is meters (m) and psi if the altitude unit is feet (ft).

In Hi Q-PRT differential mode (see Section 3.3.3.1) there are two UL values for the Hi QRPT. One is the upper and lower limts for differential pressure, with a default value equal
to the span of the Lo RPT. The other is the UL on the base mode of the Hi Q-RPT DF
range to monitor the maximum pressure on the Hi Q-RPT. In differential mode, the Lo QRPT UL is also active to provide monitoring of the differential mode line pressure.

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3. OPERATION

3.4.4.1

OVER PRESSURE FUNCTION

In addition to the UL function, RPM4 has an over pressure function.
The over pressure function executes when a Q-RPT measures a pressure that is
104 % of its default span. The G15K and BG15K Q-RPTs also have a negative
over pressure function. The negative over pressure function executes when the
Q-RPT measures a pressure less than - 17.5 kPa (- 2.3 psi).
The over pressure function causes the measured pressure display to flash.
If the Q-RPT module is equipped with SDS, SDS closes shutting off the TEST(-)
port (see Section 3.2.7). If the Q-RPT is a Gxxx or BGxxx, the TEST(+)/TEST(-)
bypass valve is opened (see Section 5.6, Figure 8). The overpressure function also
logs the time and date of the overpressure condition in both user and factory logs toassist in incident diagnosis (see Section 3.5.7.5).
To recover from an overpressure condition, cycle RPM4 power. Be sure tocorrect the condition that caused the overpressure before cycling power.

3.4.5<5AT EST >This feature not available at the time of this manual’s release. Check www.dhinstruments.com
for new RPM4 embedded software releases and manual updates.

3.5[SPECIAL] PURPOSE[SPECIAL] accesses a menu of RPM4 functions and features that are less commonly used or not
normally used in regular operation.
 OPERATION
Press [SPECIAL] from the MAIN RUN screen to access the
SPECIAL menu. The display is:

1AutoZ 2remote 3head
4SDS 5prefs 6Punit
7intern 8cal 9reset

Some screens, such as the SPECIAL menu, go beyond the two lines provided by the display. This isindicated by a flashing arrow in the second line of the display. Press the cursor control keys to move thecursor to access the lines that are not visible or directly enter the number of the hidden menu choice if you
know it.
SPECIAL menu choices include:<1AutoZ><2remote><3head><4SDS><5prefs><6Punit><7intern><8cal><9reset>Manage AutoZero function for the active Q-RPT (see Section 3.5.1).
View and edit COM port (RS-232) and IEEE-488 interface settings. Select remote syntax
style (see Section 3.5.2).
Set HEAD function fluid and height unit of measure (see Section 3.5.3).
To view and set the ON/OFF and OPEN/CLOSED status of SDS for all Q-RPTs.
View and set screen saver time, keypad sound frequency, unit ID number, time/date,security protection level (see Section 3.5.5).
Customize the [UNIT] key pressure unit of measure selections (See section 3.5.6).
Access internal functions including on-board barometer viewing, read rate adjustment, parallelmeasurement mode ON/OFF, direct control of Lo Vent valve(s), incident log viewing (seeSection 3.5.7).
View and adjust RPM4, Q-RPT and barometer calibration coefficients (see Sections 3.5.8, 5.2, 5.3).
Access RPM4’s various reset functions (see Section 3.5.9).
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RPM4™ OPERATION AND MAINTENANCE MANUAL

3.5.1<1A UTO Z>

 PURPOSE
To offset the RPM4 Q-RPT(s) readings relative to a reference value in order to compensate
for possible changes in Q-RPT zero between full recalibrations. In differential measurementmode, to compensate for the difference between the reading of the Hi and Lo Q-RPTs at the“line pressure” at which differential measurements are made.
To assure operation within measurement uncertainty specifications (see Section 1.2.2), it isrecommended that AutoZ be run (the value of Poffset updated) whenever vented in gauge mode,
whenever the line pressure is changed in differential mode and at least every 30 days or when
RPM4 has been exposed to temperature changes exceeding 15 ºC (36 ºF) in absolute mode.
 PRINCIPLE
AutoZ Purpose and Principle
The main component of the change over time of the RPM4 Q-RPTs is change in zero oroffset, independent of span. Offsetting or “rezeroing” RPM4 Q-RPTs relative to a reference
between recalibrations allows measurement uncertainty specifications to be maintained withless frequent full calibrations. AutoZ is also used to compensate for the difference between
the Hi and Lo Q-RPT at the “line pressure” at which differential measurements are made.
The RPM4 AutoZero function (AutoZ) provides full on-board support for the rezeroingprocess 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 RPM4 Q-RPT.
For Axxx (absolute) Q-RPTs in absolute measurement mode, the pressure at which
AutoZ is performed is normally atmospheric pressure and the Pstd,0 value can be supplieda) by manual entry, b) automatically from a DHI RPMx connected to RPM4 COM2
communications port, or c) automatically from an Axxx Lo Q-RPT if one is present in the
RPM4.
For Gxxx or BGxxx (gauge) Q-RPTs or Axxx (absolute) Q-RPTs in gauge measurementmode, Pstd,0 is always zero (atmospheric pressure) which is supplied by definition when
the Q-RPT is vented to atmosphere.
For RPM4s with two Q-RPTs of the same type (Axxx, Gxxx, BGxxx) with the Hi Q-RPT indifferential measurement mode, Pstd,0 is the pressure indicated by the Lo Q-RPT when
the Hi and Lo Q-RPTs are connected to a common pressure.
The pressure reading of the Q-RPT, with no AutoZ offset, at the time AutoZ is
2. Pu,0:performed.
3. Poffset,G , Poffset,A and Poffset,D: 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),absolute(A) or differential (D) measurement mode:
Poffset = Pu,0 - Pstd,0Poffset represents the difference between the Q-RPT reading (Pu,0) and the AutoZ standard(Pstd,0). The AutoZ function manages the determination, storage and application of Poffset tocorrect the zero offset in absolute, gauge and differential 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.

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3. OPERATIONThe AutoZ function can be turned ON and OFF. Table 7 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 isbeing AutoZeroed. For higher range Q-RPTs, this is easily accomplished with a variety ofdigital barometers or with a Lo Q-RPT in the RPM4. For lower range Q-RPTs, a piston gauge orother 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, running the AutoZ function to update the AutoZ value(Poffset,A), is initiated by the operator using [AutoZ].
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 are also used in gauge
and negative gauge measurement modes (difference from atmosphere) (see Section 3.3.3,
 PRINCIPLE). Gauge measurement mode is achieved by subtracting the value ofatmospheric pressure from the Q-RPT’s absolute reading using AutoZ and by dynamicallycompensating for changes in atmospheric pressure between opportunities for AutoZ to
execute (see Section 3.2.2).
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, AutoZ is run when initiated by the operator
pressing [AutoZ] when the RPM4 is vented. This assures regular updating of the Poffset,Gvalue corresponding to atmospheric pressure. Gauge pressure is the measured absolutepressure, 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 as measured by a barometer (ΔPatm) between
AutoZ updates (see Section 3.2.2). The measured gauge pressure is calculated using ΔPatm
to correct the value of Poffset.G.
Pgauge = Pu - Poffset.G - ΔPatm
In gauge measurement mode on an Axxx RPT, running the AutoZ function to update thevalue of Patm,0, is initiated by the operator using [AutoZ]. Updating of ΔPatm occurs
automatically and continuously.
When gauge or negative gauge mode is first activated on an Axxx Q-RPT, the value ofPoffset.G subtracted from the absolute pressure reading to achieve gauge pressure isstandard atmosphere of 101.325 kPa. This can cause a large zero error when gauge modeis activated if atmospheric pressure is significantly different from standard atmosphericpressure. When gauge mode is activated, always press [AutoZ] to run AutoZ and obtainan actual value of Poffset.G .

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RPM4™ OPERATION AND MAINTENANCE MANUAL

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(TEST(-)) 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.
When using a Gxxx Q-RPT in gauge measurement mode, with AutoZ ON, gauge pressure is
calculated as:
Pgauge = Pu - Poffset,GIn gauge measurement modes, AutoZ is run when initiated by the operator pressing [AutoZ]
when the RPM4 is vented. This assures the regular automated updating of the Poffset,G value.
AutoZ in differential measurement mode
RPM4s with two Q-RPTs of the same type (Axxx, Gxxx, BGxxx) support differential
measurement mode (see Section 3.3.3.1) in which the measured pressure is the difference
between the pressure measured by the Hi Q-RPT and the Lo Q-RPT (Hi – Lo).
In differential measurement mode, the purpose of AutoZ is to compensate for the offset
between the Hi and Lo Q-RPT indications at the “line pressure” at which the differential
pressure is being measured. The value of Pstd,0 is the pressure indicated by the Lo Q-RPT at
the time of AutoZ.
When using an RPM4 with two Q-RPTs in differential measurement mode, with AutoZ ON,
differential pressure is calculated as:
Pdifferential = PHi - PLo - Poffset,DIn differential measurement mode, AutoZ is run when initiated by the operator pressing[AutoZ] when both Q-RPTs of the RPM4 are connected to a common pressure..
AutoZ ON/OFF
The AutoZ function can be turned ON and OFF, separately for gauge, absolute anddifferential measurement modes. Table 7 summarizes the effect of AutoZ ON and OFF.
Table 7. AutoZ ON and OFF
Q-RPT
TYPE

MEASUREMENT
MODE

Absolute
Axxx
Gauge ornegative gauge
Gxxx
or
BGxxx
Any, Hi Q-RPTin dual Q-RPT
RPM4

Gauge ornegative gauge

Differential

AutoZ
STATUS

PoffsetAPPLIED

ON

YES

OFF

NO

ON
OFF

YES

ON

YES

OFF

NO

ON

YES

OFF

NO

ΔPatm
APPLIED

Not Applicable

AutoZ
ROUTINE
RUNS
When initiatedby operator
Not available

YESNO

Not Applicable

Not Applicable

When initiatedby operator
When initiatedby operator
Not available
When initiatedby operator
Not available

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 RPM4 Q-RPTs and maximizing the recalibration interval by compensating for change
in zero between full recalibrations. In differential measurement mode, it minimizes theuncertainty in the differential pressure due to the offset between the Hi and Lo Q-RPTs at the© 2004-2007 DH Instruments, a Fluke Company

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3. OPERATION“line pressure”. The following simple recommendations will help assure that you use thisfeature to best advantage.
•

In gauge and differential measurement mode:
operating.

•

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

•

To assure operation within measurement uncertainty specifications (see Section 1.2.2),
run AutoZ whenever vented in gauge mode, whenever the line pressure is changed indifferential mode and at least every 30 days or when RPM4 has been exposed totemperature changes exceeding 15 ºC (36 ºF) in absolute mode.

•

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 and generally is not necessary,the best possible reference with which to run AutoZ in absolute measurement mode is agas operated piston gauge (such as a DHI PG7601) applying atmospheric pressure to
the RPM4 test port. The best day to day reference is a properly calibrated DHI RPM4
with a BA100K Q-RPT interfaced directly as an external device to the RPM4 COM2 port.

•

In absolute measurement modes: Allow the RPM4 to stabilize at atmospheric pressure
and ambient temperature for 10 to 15 minutes before running AutoZ.

Always leave AutoZ ON when

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

To RUN the AutoZ routine that rezeroes the Q-RPT, use [AutoZ] (see Section 3.3.9).
To access the RPM4 AutoZ function press [SPECIAL], <1AutoZ>. The display is:1.

Active Q-RPT designator.

2.

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

3.

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

1off 2view
3edit

Hi
abs ON

Select <1off> (or <1on>) to change the AutoZ status for the current Q-RPT andmeasurement mode from ON to OFF or vice versa.
AutoZ ON is indicated by a <z> in the MAIN RUN screen, top line, fourth character fromthe right. When AutoZ is OFF, the character is blank.
Select <2view> to view the current value of Poffset for the active Q-RPT and measurement mode.
Poffset should be zero when the RPM4 is new or has just been calibrated. Poffset should beroughly equal to atmospheric pressure for an Axxx (absolute) Q-RPT operating in gauge mode.
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RPM4™ OPERATION AND MAINTENANCE MANUAL

Select <3edit> to edit the value of Poffset for the active Q-RPT and measurement mode(see Section 3.5.1.1).
The value of Poffset is always displayed and entered in Pascal (Pa).

3.5.1.1

EDIT AUTOZ
The edit AutoZ function should be used with great caution as entering
inappropriate values and turning ON AutoZ may result in out of tolerance
measurements. In normal operation, the value of the AutoZ offset, Poffset,
should be changed by running AutoZ using [AutoZ] (seen Section 3.3.9).
Before editing Poffset, see Section 3.5.1,  PRINCIPLE.

To edit the current Poffset value for the active Q-RPT and measurement mode,press [SPECIAL], <1AutoZ>, <3edit>. The display is:1.

Indication of active measurement mode(<abs> for absolute, <gage> for gauge andnegative gauge, <dif> for differential).

2.

Active Q-RPT for which Poffset is being viewed.

3.

Edit field for value of Poffset.

Poffset, Abs
8.4 PaHi

Edit Poffset as desired and press [ENT] to activate the new value. Press [ESC] toabandon changes.
The value of Poffset is always displayed and entered in Pascal (Pa).

3.5.2<2REMOTE> PURPOSE
To configure the RPM4 COM1, COM2 and IEEE-488 (GPIB) communication ports. To test COM1
and COM2 communications. To select the remote programming communications format.
 PRINCIPLEThe RPM4 has two RS-232 communications ports referred to as COM1 and COM2 and asingle IEEE-488 (GPIB) port. COM1 or the IEEE-488 port is for communicating with a hostcomputer (see Section 4), and COM2 is reserved for communicating with an external device(e.g. an RPMx, a multimeter, etc.). These ports’ settings can be viewed and changed using[SPECIAL], <2remote>.
RPM4 has two remote communications formats, classic and ENHANCED (see Section 4.3).
Which of these is active can be selected.
A self test is supplied for RS-232 communications. The self test allows verification that the
RPM4 RS232 ports (COM1 and COM2) are operating properly and that a valid interface
cable is being used.

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3. OPERATION

 OPERATION
To access the communications settings, press [SPECIAL], <2Remote>.
•

Select <1COM1> to view and edit COM1 settings (see Section 3.5.2.1.).

•

Select <2COM2> to view and edit COM2 settings (see Section 3.5.2.1.).

•

Select <3IEEE> to view and edit IEEE-488 settings (see Section 3.5.2.2).

•

Select <4format> to select the remote communications command format (see Section 3.5.2.3).

•

Select <5RS232test> to run the COM1 and COM2 communications test (see Section 3.5.2.4).

3.5.2.1<1COM1, 2COM2>

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

300, 600, 1 200, 2 400, 4 800, 9 600, 19 200, 28 800, 38 400

ParityNONE, ODD or EVEN

Length7 or 8Stop Bit

1 or 2The default is <2 400, 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 RPM4. The
RPM4 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.

3.5.2.2<3IEEE-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 sameIEEE-488 bus.
The receiving terminating character must be a line feed and EOI. Carriage returns
are ignored if received. The RPM4 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.

3.5.2.3<4FORMAT>The RPM4 has two different syntax formats available for the remote programcommands.
The classic remote command format is highly intuitive and conforms withprevious DHI PPC and RPM products.
The enhanced remote command format generally uses the same commands as
the classic format, but in addition it follows the syntax, format, and status
reporting features of IEEE Std 488.2.
The details of each format are covered in Section 4.3.
[SPECIAL], <2remote>, <4format> allows the remote program command
syntax to be selected. The cursor is on the active format. Select <1classic> or<2enhanced> as desired.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

3.5.2.4<5RS232 SELF-TEST>The RS232 self-test is provided to check the RPM4 COM ports and the interface
cable independently of an external device or computer.
If you are having difficulty communicating with RPM4 from a host computer
using RS232, the RS232 self test can help establish that the RPM4 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 [SPECIAL],<2remote>, <5RS232test>.
The display prompts you to connect COM1 to COM2 using a standard pin-to-pin
DB-9F to DB-9M RS232 cable (see Section 4.2.1.1, 4.2.1.3).
Once the cable has been installed, press [ENT] 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 followedby the conclusion, <The RS232 test has
PASSED>.

If a test fails:

Execution is suspended until [ENT] ispressed.

The RPM4 RS232 test can fail for three reasons:
1. The RS232 cable being used is incorrect (Section 4.2.1.1, 4.2.1.3 for
information on the correct cable).
2. COM1 and COM2 do NOT have the same serial communications settings
and therefore cannot communicate together (see Section 3.5.2.1 to set
the COM ports).
3. COM1 or COM2 is defective.
The reason for failed communications is almost always a cable or incorrect
RS232 interface settings. Be sure that these are correct before concludingthat a COM port is defective.

3.5.3<3HEAD> PURPOSE
To view or change the properties of the HEAD function (see Section 3.3.7) including the unit ofmeasure of length for head height entry and the test fluid type and species for density calculations.
 OPERATION
From the MAIN RUN screen, pressure [SPECIAL], <3Head>.
Select the desired height unit of measure and press [ENT].
Select <1gas> or <2liqud> depending on the pressurized medium between the RPM4 andthe height at which pressure is to be calculated. Select the gas or liquid species. The liquid
selection <3User>, is to create a custom liquid with a user entered density.
Use [HEAD] to set a head height if desired.

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3. OPERATION

3.5.4<4SDS>

 PURPOSE
To open and close SDS temporarily for the Hi or Lo Q-RPT or to turn the SDS function ON
and OFF full time for the Hi or Lo Q-RPT.
See Section 3.2.7 for complete information on RPM4’s SDS (Self Defense System) feature.
 PRINCIPLE
SDS is a self defense system to protect RPM4 Q-RPTs from overpressure (see Section 3.2.7).
Normally, opening and closing SDS is performed automatically by the RPM4 or by theoperator using the [SDS] key.
[SPECIAL], <4SDS> gives further control over the SDS function.
This includes:a) the possibility of temporarily opening or closing SDS on either the Hi or Lo Q-RPT (seeSection 3.5.4.1), and; b) turning OFF SDS so that it is open full time and RPM4 can be
operated as if SDS were not installed (see Section 3.5.4.2).
The temporary opening or closing of SDS allows the SDS open/closed state to be set
immediately to the desired state. Following the change, normal automated operation of SDS
and control using the [SDS] key is still valid. This function is often used to open SDS on theinactive Q-RPT in PRM4s with dual Q-RPTs.
Setting the SDS function to full time OFF eliminates the SDS function completely until is set
to full time ON again.

3.5.4.1<1TEMP OPEN/CLOSE>OPERATION
See Section 3.2.7 for complete information on RPM4’s SDS (Self Defense
System) feature.

To temporarily open or close the SDS of the Hi or Lo Q-RPT press [SPECIAL],<4SDS>, <1temp open/close>. If the RPM4 has two Q-RPTs and both have
SDS, the Q-RPT must then be selected. The next display is:
The cursor is on the current state of SDS for thedesignated Q-RPT. Select <1close> to close
SDS or <2open> to open SDS and return to the
MAIN RUN screen. [ESC] to return without
making changes.

SDS temporary:
1close 2openHi

If <2open> is selected and SDS for the Q-RPT is not already open, the SDS
opening screen with indication of the maximum pressure of the Q-RPT is displayed.
This is the same screen used when opening SDS using the [SDS] key (seeSection 3.3.8). Check that the pressure applied to the Q-RPT module TEST(+)
port does not exceed the Pmax! value before confirming that SDS should be opened.
Opening SDS with a pressure greater than Pmax! applied to the test port
may cause overpressure damage to the Q-RPT.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

3.5.4.2
<2FULL TIME ON/OFF>OPERATION
See Section 3.2.7 for complete information on RPM4’s SDS (Self Defense
System) feature.

Turning SDS “full time OFF” for a Q-RPT module eliminates normal SDS
operation so that the Q-RPT module TEST(+) port remains open. However,the SDS overpressure function (see Section 3.4.4.1) remains active.
To turn SDS full time ON or OFF for a Q-RPT module, press [SPECIAL],<4SDS>, <2full time on/off >. If the RPM4 has two Q-RPTs and both have SDS,
the Q-RPT must then be selected. The next display is:
The cursor is on the current state of SDS for thedesignated Q-RPT. Select <1on> to set SDS for
normal operation and return to the main run
screen. Select <2off> to open SDS permanently
so operation is as if SDS were not installed.
[ESC] to return without making changes.

SDS full time:1on 2offHi

If <2off> is selected and SDS for the Q-RPT is not already open, the SDS opening
screen with indication of the maximum pressure of the Q-RPT is displayed. This is
the same screen used when opening SDS using the [SDS] key (see Section
3.3.8). Check that the pressure applied to the Q-RPT module TEST(+) port does
not exceed the Pmax! value before confirming that SDS should be opened.
Opening SDS with a pressure greater than Pmax! applied to the test port
may cause overpressure damage to the Q-RPT.

3.5.5<5PREFS> PURPOSE
To access a menu of RPM4 operational preferences and functions.
 OPERATION
To access the PREFS menu press [SPECIAL],<5prefs>. The display is:

1ScrSvr 2sound 3time
4ID 5level

The PREFS menu includes:<1ScrSvr>

View and change the screen saver activation time (see Section 3.5.5.1).

<2sound>View and change the keypress sounds (see Section 3.5.5.2).

<3time>View and edit the internal time and date settings (see Section 3.5.5.3).

<4ID>

View the RPM4 serial number (SN) and view or edit the ID number(see Section 3.5.5.4).

<4level>View and set user security level and/or password (see Section 3.5.5.5).

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3. OPERATION

3.5.5.1
<1S CR S VR >PURPOSETo adjust the idle time after which RPM4’s SCREEN SAVER activates.


PRINCIPLE

RPM4 has a SCREEN SAVER function which causes the display to dim after afront panel key is NOT pressed for a certain amount of time. The default is for thescreen saver to activate after 10 idle minutes. The screen saver activation time
can be adjusted by the user or screen saving can be completely eliminated.
Setting screen saver time to zero eliminates the SCREEN SAVER function sothat the display permanently remains at full brightness.


OPERATION

To access the SCREEN SAVER function, press [SPECIAL], <5prefs>,<1ScrSav>. 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.

3.5.5.2
<2SOUND>PURPOSETo adjust or suppress the RPM4 valid key press sound.


PRINCIPLE

RPM4 provides audible feedback by a brief “beep” when a valid key press ismade. The tone frequency of this beep may be selected from three choices or it
may be completely suppressed. Invalid key presses are indicated by adescending two tone “blurp” which cannot be suppressed.


OPERATION

To access the keypad sound adjustment function press [SPECIAL], <5prefs>,<2sound>.
Select between <2lo>, <3mid> or <4hi> to adjust the valid key press tone frequency.
Select <1none> to suppress the valid key press tone.
The sound function only affects the valid key press tone. The invalid key
press tone and other RPM4 sounds cannot be adjusted or suppressed.

3.5.5.3
<3TIME>PURPOSETo view and edit the RPM4 internal time and date settings.


OPERATION

To
accessthe
TIME
functionpress [SPECIAL], <5prefs>, <3time>.
The display is:Page 67

Edit: 1time 2date
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RPM4™ OPERATION AND MAINTENANCE MANUAL

Select <1time> to edit the time. Edit hours, then minutes, then am/pm bypressing [ENT] after each entry. Seconds go to zero when minutes are entered.
This can be used to synchronize the time with a time standard.
Select <2date> to edit the date. The date must be specified in YYYYMMDD format.
The RPM4 date and time are set to United States Mountain Standard Timein the final test and inspection process at the factory. If desired, use the
TIME and DATE function to set your local time and date.

3.5.5.4<4ID>

PURPOSETo view or edit the RPM4 user ID and to view the RPM4 serial number.


OPERATION

To access the ID function press [SPECIAL] and select <5prefs>, <2ID>.
Select <1view> to view the current ID.
Select <2edit> 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
alphanumeric characters. Holding the key slews through the characters.
Character order going up is: blank space, symbols, lower case letters, upper
case letters, numbers. After selecting a character, press [ENT] 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, press [ENT] with the field for that character blank. Use this forthe 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.
Select <1no> to return to the ID edit screen. Select <2yes> to save the edited ID.
The ID can be set remotely from a computer which is quite a bit moreconvenient than entering characters from the keyboard (see Section 4.4.4,
ID command). The ID is not cleared or reset by any RESET function(see Section 3.5.9).

3.5.5.5
<5LEVEL> (SECURITY)PURPOSETo set user protection levels to restrict access to certain functions and to edit the
password required for changing user levels.


PRINCIPLE

RPM4’s front panel user interface provides the means to access all RPM4 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 RPM4 is being used, it may be desirable to restrict access to somefunctions. The user level function provides a means of restricting access to certain
functions. Four different levels of security are available.
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3. OPERATION

Access to changing security levels can be left open, or be protected by a password.
Security Levels
The security levels are structured to support typical operating environments as follows:
None

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.

MediumMedium security is designed to protect specific metrologicalinformation in the system and to assure that the RPM4 is operatedusing consistent operational parameters.

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.
RPM4 is delivered with the security level set at 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. If there is a risk of unauthorized changing of the
security level, changing authority should be password protected(see  OPERATION of this section).

The security levels are structured to support typical levels of operation as shownin Table 8. Specifically, the security levels prevent execution of the functions
accessed by the key strokes marked by “•”:

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RPM4™ OPERATION AND MAINTENANCE MANUAL

Table 8. Security Levels
FUNCTIONLOWMEDIUM[RANGE][ENT] (AutoTest)[UNIT][MODE]•[AutoRange][LEAK CK]•[DISPLAY][HEAD][SDS]•[AutoZ] (in absolute mode)[SETUP]•••[SETUP], <1range>[SETUP], <2res>[SETUP], <4UL>[SPECIAL][SPECIAL], <1AutoZ>[SPECIAL], <1AutoZ>, <1on/1off>[SPECIAL], <1AutoZ>, <3edit>

•
•

•
•
•

[SPECIAL], <2remote>[SPECIAL], <2remote>, make changes[SPECIAL], <3head>[SPECIAL], <4SDS>[SPECIAL], <5pref>, <1ScrSvr>[SPECIAL], <5pref>, <2sound>[SPECIAL], <5pref>, <3time>[SPECIAL], <5pref>, <3time>, make changes
SPECIAL], <5pref>, <4ID>, <2edit>••[SPECIAL], <6Punit>[SPECIAL], <7internal>[SPECIAL], <7internal>, <3RPT2x>[SPECIAL], <7interrnal>, <5log>, clear log••[SPECIAL], <8cal>[SPECIAL], <8cal>, <2edit> under any selection•[SPECIAL], <4reset>[SPECIAL], <4reset>, <4cal>[SPECIAL], <4reset>, <5all>••

Remote communications disabled“•” indicates the function/menu is NOT accessible.

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•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

HIGH

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

3. OPERATIONOPERATION

RPM4 is delivered with no active password and access to the User Level menu is
open. The user level is set to <1Low>. User levels can be changed freely until apassword has been created.
To
accessthe
LEVEL
functionpress [SPECIAL], <5prefs>, <5level>.
The display is:

1change user level2edit password

Selecting <1change user level> brings
up the restriction menu:

Restrictions: 1none
2low 3medium 4high

The cursor is on the current restriction level.
or [ESC] back to the MAIN RUN screen.
If no password is active, selecting<2edit password> displays the user
password and allows it to be edited.

Select a different level or

Password: pppppp
0 disables password

Once a password has been entered, the user level cannot be changed 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
to enter a password to access the user level menu. This condition, with asecurity level of <2low>, is the factory default.
If there is an active password, theRPM4 password entry screen appears.
The user must enter the user definedpassword or the factory secondary
password to proceed further:

RPM4 SNnnnn-xx
Password: pppppp

The first field, <nnnn>, is the serial number of the RPM4, followed by a second field,<xx>, that represents the number of times that a secondary password has beenused. The second field, <xx>, increments each time a secondary password isused. The third field, <pppppp> is for user entry of the normal password.
The factory secondary password is available in case the user’s password has
been misplaced or forgotten. It can be obtained by contacting a DHI
Authorized Service Center (see Table 29). The factory secondary password
is different for all RPM4’s and changes each time it is used.

3.5.6<6PUNIT> PURPOSE
To customize the selection of pressure units of measure that are available in the [UNIT] key menu.

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RPM4™ OPERATION AND MAINTENANCE MANUAL PRINCIPLE
The [UNIT] function key makes available a choice of six default pressure units (US or SI units
depending on whether the RPM4 has been factory set as US or SI) (see Section 3.3.2).
RPM4 also supports many commonly used units other than those included in the default set up.
These units can be made available for active selection by customizing the UNIT function
using [SPECIAL], <6PresU>. This allows RPM4 to offer a very wide selection of units while
simplifying day to day operation. The typical user customizes the [UNIT] function key tosupport his/her six most commonly used units.
 OPERATION
To customize the [UNIT] function key, from the MAIN RUN screen press [SPECIAL],<6PresU>. The display is:1.

Entry field to specify which unit position (1 to 6) of the [UNIT]
function key menu is to be changed.

Set up unit #6

Unit#6 1SI 2other3altitude 4user

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

Select the desired pressure unit category (SI units include units based on SI units such asmmHg), then select the desired unit from the unit menu.
The units of measure available are listed in Table 9.
Table 9. UNIT Function - Available Units of Measure<1SI><2OTHER><3ALTITUDE><1Pa><2hPa><3kPa><4MPa><5mbar><6bar><7mmHg><8mmWa><1psi><2psf><3inHg><4inWa><5kcm2><6Torr><7mTor><1feet><2meters><4USER>If <4user> 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. Pressing [ENT] defines theuser unit and returns to the <Set up unit #n> screen.
The user defined unit label can be customized to any alphanumeric, four character label
using the remote command “UDU” (see Section 4.4.4).

See Section 7.2.1 for the pressure unit conversion factors used by RPM4.

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3. OPERATION

3.5.7<7INTERNAL> PURPOSE
To view, set, adjust, and maintain various aspects of RPM4’s internal operation.
 OPERATION
To access the internal selections press [SPECIAL],<7internal>. The display is:

1baro 2ReadRt 3RPT2x
4lo vnt 5log

The INTERNAL menu choices include:<1baro>View the real time output of the on-board barometer, if present (see Section
3.5.7.1).

<2ReadRt>

Turn ON and OFF RPM4’s automated, rate of change dependent, reading
integration rate feature (see Section 3.5.7.2).

<3RPT2x>

Enable and disable RPM4 parallel measurement mode in which two Q-RPT
modules are used to measure in parallel and their readings are averaged(see Section 3.5.7.3).

<4lo vnt>

Operate Q-RPT module Gxxx and BGxxx low VENT valve directly(see Section 3.4.7.4).

<5log>

View the RPM4 incident log (see Section 3.5.7.5).

3.5.7.1
<1BARO>PURPOSETo view the value of atmospheric pressure as measured by the RPM4 on-board
barometer.
There is no on-board barometer in RPM4s that have G100K or G200K
Q-RPTs only”.


PRINCIPLE

RPM4’s that include an Axxx (absolute) and/or BGxxx (bi-directional gauge)
Q-RPT are equipped with a separate, on-board barometer. The atmosphericpressure measurements made by the on-board barometer are used for dynamic
compensation of atmospheric pressure when using an Axxx Q-RPT to make gaugepressure measurements (see Sections 3.3.3,  PRINCIPLE and 3.2.2) and for staticpressure compensation when using a G15K or BG15K Q-RPT.
See Section 5.5, Figure 7 and Section 5.6, Figure 8 for a photo andschematics showing the position of the on-board barometer in RPM4.

The on-board barometer is a low accuracy sensor used only for measuring
small changes in atmospheric pressure over short periods of time(see Section 3.2.2) and for line pressure compensation when using a G15K or
BG15K Q-RPT. RPM4 measurement uncertainty does not depend on themeasurement uncertainty of the on-board barometer.

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RPM4™ OPERATION AND MAINTENANCE MANUALOPERATION
RPM4’s that have only G100K or G200K Q-RPTs (no Axxx, G15K or BG15K)
are NOT equipped with an on-board barometer.

To view the current reading of the on-board barometer press [SPECIAL],<7internal>, <1baro>. The display is in the active pressure unit of measure(see Section 3.3.2). The display resolution is fixed to 0.01 Pa, or its equivalent.

3.5.7.2<2R EAD R T >PURPOSETo turn ON and OFF RPM4’s automated, rate of change dependent, reading
integration rate feature.


PRINCIPLE

To obtain maximum resolution from RPM4 Q-RPT pressure measurements, anintegration time of about 1.2 second per reading is used. In most situations,maximum precision is needed when pressures are stable so a relatively slow
display update rate presents no disadvantage. However, when pressure ischanging quickly, more rapid pressure updates are usually more important thanobtaining maximum precision on individual readings. The RPM4 read ratefunction automatically adjusts pressure measurement integration time dependingon the rate of change of pressure. When pressure is changing rapidly, reading
rate is increased. When pressure is evolving slowly, reading rate is decreased
and maximum precision is obtained.
When the automated read rate function is ON, three pressure rate of change
dependent read rates are used. The result is three display update rates:
Table 10. READRT - Display Update Rates
PRESSURE
RATE OF CHANGEDISPLAYUPDATE> 3 % of range span/s≈ 0.2 s> 0.5 and < 3 % of range span/s≈ 0.6 s< 0.5 % of range span/s≈ 1.2 sFor situations in which maximum reading precision is desired regardless ofpressure rate of change, the RPM4 automated read rate function can be turned
OFF. In this case, the reading rate is always the high resolution rate of about 1.2
seconds per reading.


OPERATION

To turn the automated read rate function ON or OFF or check its current status,press [SPECIAL], <7internal>, <3ReadRt>.
Auto read rate:
1on 2off

The display is:
The cursor is on the current selection.

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3. OPERATION

Selecting <1on> activates the automated reading rate and returns to the MAIN
RUN screen. Selecting <2off> turns OFF the automated reading rate andreturns to the MAIN RUN screen.
The default RPM4 condition is auto read rate ON. The read rate can be set to a
fixed value between 200 ms and 20000 ms using the remote command“READRATEn” (See Section 4.4.4).

Auto read rate ON/OFF is NOT Q-RPT or range specific. Turning auto readrate ON or OFF in one range turns it ON or OFF for all RPM4 ranges.

3.5.7.3
<3RPT2 X >PURPOSETo enable and disable the RPM4 parallel measurement mode in which two
Q-RPT modules are used to measure in parallel and their readings are averaged.


PRINCIPLE

RPM4s that have two Q-RPT modules of the same type (Axxx, Gxxx or BGxxx)
support parallel measurement mode. In this mode, both Q-RPTs are used tomeasure the same pressure in parallel and their readings are averaged.
Parallel measurement mode sets up a third Q-RPT designated HL (combinationof Hi and Lo). The HL RPT can be selected by the [RANGE] function andsupports other RPM4 functions such as UNIT, MODE and DISPLAY.
When parallel measurement mode is set up, the resulting HL Q-RPT can be athird Q-RPT in addition to the Hi and Lo RPTs. It is also possible to make the HL
Q-RPT the sole Q-RPT, suppressing the Hi and Lo Q-RPTs. This feature is used
when an RPM4 will always be used in parallel measurement mode and theavailability of the individual Hi and Lo Q-RPTs is not desired.
[SPECIAL], <7internal>, <3RPT2x> is used to set up or suppress parallelmeasurement mode in RPM4s that support it.
In parallel measurement mode, the maximum pressure is the maximum
pressure of the Lo Q-RPT.


OPERATION
Parallel measurement mode is only available on RPM4s with two Q-RPTs of
the same type (Axxx, Gxxx, BGxxx).

To access the parallel measurement mode enable/disable function press[SPECIAL], <7internal>, <3RPT2x>.
The cursor is on the number corresponding to the current setting.
Select <1off> to disable parallel measurement mode. This will eliminate the HL
Q-RPT.
Select <2on> to enable parallel measurement mode. This creates the HLparallel mode Q-RPT. The Hi and Lo Q-RPTs are also still available.
Select <3on, w/ Hi & Lo RPT off> to enable parallel measurement mode anddisable access to the Hi and Lo Q-RPTs individually. This creates the HLparallel mode Q-RPT and makes it the sole Q-RPT available for selection.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

Operation returns to normal when the disagreement between the two Q-RPTs
returns to normal.
When using parallel measurement mode, the Hi and Lo Q-RPTs should beconnected IN PARALLEL to the pressure to be measured (both Q-RPTs
connected to the same pressure). The measured pressure indicated inparallel measurement mode is the average of the Hi and Lo Q-RPTs.

3.5.7.4
<4LO VNT>PURPOSETo cause an RPM4’s Gxxx or BGxxx Q-RPT TEST(-) vent valve to stay open or
closed rather than open and close automatically.
This feature is active only when the active Q-RPT is a Gxxx (gauge) or
BGxxx (bi-directional gauge) Q-RPT.


PRINCIPLE

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 8, Gxxx, BGxxx, Valve C).
The TEST(-) vent valve is used to open the TEST(-) port to atmosphere which
also connects the Q-RPT and the device or system under test low side to atmosphere.
In normal RPM4 operation, the TEST(-) valve is closed to isolate the low pressure
circuit from fluctuations in ambient pressure when the Q-RPT is being used tomeasure pressure. It is open only when SDS is closed (see Section 3.2.7).
However, it may be desirable to open the TEST(-) port to atmosphere whilemeasuring pressure and/or without closing SDS. For example, this may benecessary to assure that the pressure on the low side of the Q-RPT and thesystem under test does not move too far away from atmosphere. [SPECIAL],<7internal>, <4lo vnt> allows the TEST(-) vent valve to be set to bepermanently open, permanently closed or to operate in its default, automatedcondition. It also allows the current status of the valve to be viewed.


OPERATION
The normal, default setting for the TEST(-) vent valve is <1auto> in which RPM4
automatically controls the valve based on current Q-RPT module operation.
Setting other than <1auto> should only be selected by advanced users.

To access the LO VNT function press [SPECIAL], <7internal>, <4lo vent>. If theRPM4 does not have a Gxxx (gauge) or BGxxx (bi-directional gauge) Q-RPT, thedisplay is: <Available with Gxxx or BGxxx Q-RPT only>. If the RPM4 hasmore than one Gxxx or BGxxx Q-RPTs, the Hi or Lo Q-RPT must be selected.
Test(-) vent:1auto
2open 3close 4view

The next display is:

Select <1auto> for the TEST(-) vent valve operation to be controlled automaticallyby RPM4 based on current operation. This is the default and recommended setting.
Select <2open> to cause the TEST(-) valve to open and remain open regardlessof RPM4 operation until the setting is changed. If RPM4 detects a condition© 2004-2007 DH Instruments, a Fluke Company

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3. OPERATION

in which it determines there could be a risk of overpressure to the Q-RPT
by opening the TEST(-) vent valve, the message <Cannot open lo vent,
DP overpressure risk> is displayed. If this message is displayed, return tonormal operation, vent the RPM4 Q-RPT module and try again.
Select <3close> to cause the TEST(-) vent valve to close and remain closed
regardless of RPM4 operation until the setting is changed.
Select <4view> to view the current condition of the TEST(-) valve. The display
indicates whether current valve operation is controlled by the RPM4(<Auto TEST(-) vent>) or has been set manually (<Manual TEST(-) vent>)
followed by the current valve status (<Open> or <Close>).
If the RPM4 is being used as an external device to a PPC3 pressure controller(see Section 3.5.7.4), the Lo Vent setting may be changed from the PPC3
(see the PPC3 Operation and Maintenance Manual).

3.5.7.5<5LOG>PURPOSETo view and/or clear the RPM4 event log.


PRINCIPLE

RPM4 records to a log each time one of the following events occurs:•

Pmax! of an internal RPM4 Q-RPT or utility sensor is exceeded (see Section
3.4.4.1).

•

A memory fault occurs.



OPERATION

To view the event log press [SPECIAL], <9Log>.
Use [] 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 theeven time and date. Use [ ] 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, <1no>, <2yes> ispresented. Use <2yes> to remove all entries from the log. Use <1no> tocontinue without altering the log.
To leave the log, use [ESC].

3.5.8<8CAL>

 PURPOSE
To calibrate the RPM4 Hi and Lo Q-RPTs and adjust the on-board barometer. These
functions are considered part of RPM4 maintenance and are covered in the maintenancesection of this manual (see Sections 5.2, 5.3).
 PRINCIPLE
See Sections 5.2, 5.3.
 OPERATION
See Sections 5.2, 5.3.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

3.5.9<9RESET> PURPOSE
To reset various RPM4 settings to default or factory values.
 PRINCIPLE
RPM4 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 any
settings that the user has made, and should be used only to restore the RPM4 to a known
state. RPM4 goes through its power up sequence after any type of reset is executed.
RPM4 reset functions will change current settings to factory defaults. These may include
settings vital to RPM4 operation and affecting the calibration of the quartz reference
pressure transducers (Q-RPTs). Reset functions should only be used by qualified personnel
with knowledge of reset consequences. Reset functions should never be used “experimentally”.
 OPERATION
To access the RESET menu, press [SPECIAL],<9reset>. The display is:

1sets 2units 3ATest
4cal 5all

RESET menu choices include:<1set>

to reset general system operating parameters (see Section 3.5.9.1).

<2units>

to reset unit of measure functions (see Section 3.5.9.2).

<3ATest> to reset AutoTest parameters and clear the AutoTest data log (see Section 3.5.9.3).
<4cal>

to reset internal calibration coefficients and modes (see Section 3.5.9.4).

<5all>

to reset all settings except ID and security password to factory default values(see Section 3.5.9.5).

3.5.9.1
<1SETS>PURPOSE

Sets most general operating parameters back to default values. Does not affectcalibration coefficients, remote interfaces or AutoRange ranges. The Reset – Sets
resets are itemized in Table 11.

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3. OPERATION

Table 11. Reset – SetsRESET

RESULT

SEE SECTION[UNIT]

Pressure unit of measure to first of the six available

3.3.2[MODE]

Measurement mode to the native mode of the Q-RPT

3.3.3[RANGE]

Hi Q-RPT default range

3.3.1[HEAD]

0 cm height and Nitrogen medium

3.3

Stability Limit

0.005 % of Hi Q-RPT default range

3.4.3

Upper Limit

Hi Q-RPT default range default value

3.4.4

Resolution

0.001 % FS of Hi Q-RPT default range

3.4.2

AutoZ

AutoZ ON for all Q-RPTs and measurement modes.
Zoffset value not affected

3.5.1

AutoZ

Patm,0 set to 101.325 kPa a

Leak Check

15 second run time. Clear logged results

3.3.5

Screen Saver

10 minutes to activation

3.5.5.1

Key Sounds

Medium tone valid key press sound

3.5.5.2

Lo VntAutomatic

3.5.7.4

ReadRate

Automatic

3.5.7.2

3.5.9.2


3.5.1, 3.2.2<2 UNITS>PURPOSE

Sets the six pressure units available under the UNIT function to the SI or US
default selections depending on whether the RPM4 has been factory set for SI or US(see Section 3.3.2).
Sets the user defined unit to 1.000/Pa (see Section 3.5.6).
Sets the reference temperature for inWa unit to 20°C.

3.5.9.3<3AT EST >

PURPOSE•

Resets Auto Tests to default characteristics (see Section 3.3.10).

•

Clears AutoTest data log (see Section 3.4.5).

3.5.9.4<4 CAL>PURPOSEThe Reset - Cal function will reset Q-RPT, utility sensor and barometer
calibration coefficients and settings and reset AutoZ values to zero. This
will change the RPM4 calibration and could cause it to make out of tolerance
measurements.

Clears all user values affecting the calibration of Q-RPTs and the on-board
barometer. The Reset – Cal resets are itemized in Table 12.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

Table 12. Reset – CalRESETRESULT

SEE SECTION

All Q-RPT Calibration
Coefficients

PA to zero, PM to 1

5.2.1.1, 5.2.7

Axxx Q-RPT absolute andnegative gauge mode

ON

5.2.5

On-board Barometer
Calibration Coefficients

PA to zero, PM to 1

5.3

Calibration Date

Set all dates to 19800101

AutoZ values

Axxx Q-RPTs: All Poffset values to zero forabsolute mode and 101325 Pa for gauge andnegative gauge modes

5.2.7, 5.3
3.5.1

Gxxx, BGxxx Q-RPTs: All Poffset values to zero
AutoZ function

3.5.9.5ON, all Q-RPTs, all measurement modes

3.5.1<5 ALL>PURPOSEThe 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 except the ID function (see Section 3.5.5.4) andthe security level password (see Section 3.5.5.5) returning RPM4 to the“as delivered” condition. The Reset – All resets are itemized in Table 13.
Table 13. Reset – AllRESETRESULT

SEE SECTION

Reset – Sets

All the resets of Reset - Sets

3.5.9.1

Reset – Units

All the resets of Reset - Units

3.5.9.2

Reset – Atest

All the resets of Reset - ATest

3.5.9.3

Reset – Cal

All the resets of Reset - Cal

3.5.9.4

Remote Interfaces

COM1, COM2 and IEEE-R88 interfaces todefault settings.

3.5.2

Remote Communications

Remote command format to Classic

3.5.2.3

Level (Security)

Reset security level to low

3.5.5.5

Parallel Measurement Mode

Off

3.5.7.3

SDS

All SDS full time ON

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4. REMOTE OPERATION

4.

REMOTE OPERATION

4.1

OVERVIEW

Most of the RPM4 front panel functions can also be executed by commands from a remote computer.
The host computer can communicate to the RPM4 using the RPM4’s COM1 RS232 port or it’s IEEE-488 port.
Before writing test code using RPM4 remote commands, familiarize yourself with its operating principles
by reading Section 3 of this manual.

4.2

INTERFACING

Sending a program message to the RPM4 places it into remote mode. The remote indicator to the rightof the display window lights when the RPM4 is in remote mode. It also flickers when a program message
is received. The menus usually accessed from the front panel are locked out while in remote. The [ESC]
key returns the RPM4 to local operation unless the <REMOTE> program message, which locks out all
keypad operation, was sent to the unit.

4.2.1

RS232 INTERFACE
4.2.1.1

COM1

The RPM4 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.
Handshaking is not required or supported. The COM1 receive buffer is
80 bytes deep. If you overflow the buffer by sending too much data, the data will
be lost. Because of this, you must send a single program message at a timeand you must wait for the RPM4 to reply from the previous command before
issuing another command.
Table 14. COM1 Pin Designations and Connections
RPM4 COM1 DB-9F PIN DESIGNATIONSPIN #FUNCTION

2TxD

DESCRIPTION

3RxD

This pin accepts serial data from the host computer.

5

Grn

This pin is the common return for the TxD and RxD signals.

This pin transmits serial data from the RPM4 to the host.

IBM PC/XT DB-9F
CONNECTIONSIBM PC/XT DB-9M TO RPM4 DB9F
CONNECTION

DB-25M

DB-9F

DB-9M

2

3

3

3

3

2

2

2

7

5

5

5

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4.2.1.2

IEEE-488

The RPM4 IEEE-488 interface is located on the back of the unit. The physicaland electrical interface conforms to IEEE Std 488.1-1987 Subset E2 and IEEE
Std. 488.2-1992. You should not attempt to communicate with the IEEE-488
interface while using the COM1 interface. The IEEE-488 receive buffer is 250
bytes deep. If you attempt to overflow the buffer, the RPM4 will hold off releaseof the NRFD handshake line until it can service and empty the receive buffer.
This keeps the buffer from overflowing. It is recommended that you check forerrors using the “ERR?” query after sending a group of non-query program
messages. When using queries, ensure that you wait for a reply to each query toensue proper operation and order of command execution. Replies to queries
remain in the reply queue until the host gets them, so they can “stack up”,
causing replies to appear out of sequence.

4.2.1.3

COM2

The RPM4 COM2 RS232 interface is located on the back of the unit. It can be used
to allow the host computer to communicate with another device through the RPM4.
This allows the user to use one host COM port to communicate with the RPM4 andan additional RS232 device. Refer to the “#” remote program command for
details. When using the RPM4 as a reference for a PPC3, another RPM4 can beconnected to the first RPM4’s COM2 port, allowing the PPC3 to communicate
with both RPM4s (see Section 3.2.5).
COM2 is a 9-pin female DB-9F connector configured as a DTE device. Data istransmitted out of the RPM4 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.
Table 15. COM2 DB-9F Pin Designations

4.3

PIN #

FUNCTIONDESCRIPTION

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.

This pin transmits serial data from the RPM4 to a device.

PROGRAMMING FORMATS

RPM4 supports two program message formats, the “classic”, and the “enhanced” formats. The user
must select which format to use. Selection can be accomplished from the front panel (see Section
3.5.2.3) or remotely using the “L2” or “L3” program message (see Section 4.4.4). The ”MSGFMT”
command can also be used to select the format, but is not recommended for new designs.
The main difference between the “classic” and “enhanced” formats is that when using the IEEE-488 interface,a query operator “?” must be included in an enhanced command to yield a reply from the RPM4. Whenusing the COM1 port in classic or enhanced mode or using the IEEE-488 port in classic mode, every
command has a reply which the host must wait for before continuing. In addition, the enhanced message
format supports IEEE Std 488.2 syntax, format and status reporting. The default is the classic format.
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.
Many RPM4 classic and enhanced commands are common with PPC2+, PPCK+ and PPC3
Pressure/Controller Calibrators.

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4.3.1

CLASSIC PROGRAM MESSAGE FORMAT

Each program message sent is also a query. You can only send one program message to
the RPM4 at time. After sending any program message, you must wait for the RPM4 to reply
before sending another program message. This reply will contain data, or a numeric error
message if the program message was invalid. You must wait for this reply before issuing
another program message to the RPM4. This insures that the RPM4 has completed theprogram message. Most remote program messages will return a reply within 500 ms except:“PR?”, “PRR?”, “SR?”, “ATM?”, “RATE?”: Up to 2 seconds.
“RPT”, “ARANGE”, “AUTOZERO=RUN”: Up to 3 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 4.4.4.

4.3.2

ENHANCED PROGRAM MESSAGE FORMATThe 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 4.5.2). 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.

4.3.2.1

USING COMMAND TYPE COMMANDS
Enhanced format commands DO NOT reply when using the IEEE-488
interface unless a “?” is included in the command. Do not expect a response
from the RPM4’s IEEE-488 interface to non-query (no “?”) commands as
there is none. Remote software will time-out waiting for a response from
RPM4. However, in RS232 communications, there is always a response andthe response MUST be read prior to issuing another command.

The COMMAND type of program message executes a process and can
additionally send data to the RPM4 in the form of comma delimited arguments.
This data is usually a setting of some sort that is stored in the RPM4. 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 4.4.4.
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.

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Examples:•IEEE-488 enhanced mode command series using query operator:“*CLS?”“UNIT? KPA”
“MMODE? A”
“PR?”

•

IEEE-488 enhanced mode commands without query operator:“*CLS”“UNIT KPA”
“MMODE A”“ERR?”•(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)(Clear the error queue. 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”“UNIT KPA;MMODE A”“ERR?”•(Clear the error queue. No reply)(Two command at once. No reply)(Wait for reply. User should use “ERR?”
query following a series of non querycommands to check for errors that may
have occurred)

COM1 enhanced mode command:“*CLS” or “*CLS?”“UNIT KPA” or “UNIT? KPA”
“MMODE A” or “MMODE? A”“PR” or “PR?”4.3.2.2(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 COMMANDSThe QUERY type of program message just requests data from the RPM4.
Placing the query operator “?” immediately after the command creates a query.
You must wait for a reply with a query. If you send any type of program
message to the RPM4 after a query before receiving a reply, the program
message is discarded and an error is generated. Errors are reported using theIEEE Std. 488.2 status reporting model. A Query program message always ends
with a question mark. Most queries return a reply within 200 ms except:“PR?”, “PRR?”, “SR?”, “ATM?”, “RATE?”: Up to 2 seconds.
“RPT”, “ARANGE”, “AUTOZERO RUN”: Up to 3 seconds
The syntax for using a QUERY program message is listed next to the keyword“Query:” in each program message summary in Section 4.4.4. Please note thatqueries in enhanced mode via the IEEE-488 port that results in an error will not
result in a reply. You must check the error queue (use the “ERR” querie) to see
if an error has occurred.

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4.4

COMMANDS
4.4.1

PROGRAMMING MESSAGES

Some commands accept an optional suffix. This suffix can be used to specify the explicit Q-RPT
to address. In most cases, each Q-RPT in the RPM4 operates as an independentmeasurement device. If the suffix is not specified, then the “Active” Q-RPT is assumed.
The “RANGE” or “ARANGE” command can be used to select the “Active” Q-RPT. There aresome limitations to use of the suffix when the RPM4 is in differential mode (see Section
3.3.3.1) or the “HL” Q-RPT is active (see Section 3.2.4). See the program message
descriptions for suffix use with a specific command.
Table 16. Program Message List
COMMAND‘n’ indicates anoptional suffix#
ABORT
ARANGEnATM
AUTOZEROn
AUTOZEROn=RUN
CALAMB
COM1
COM2
CONTn
DATE
ERR
GPIB
HEAD
ID
L2
L3
LLn
LOCAL
MEM
MMODEnMSGFMT
NVENTn
PCALn
PCAL:XX
PRn
PRRn
QPRRn
RANGE
RATEn
READRATEn
READYCKnREMOTE
RESn
RESET
RPTn
SCRSAVSDSn
SDSACTSDSAUTOn
SN
SRn
SSn
SS%n
TIME
UCOEFnUDU

DESCRIPTION
Send a command string out of the RPM4 COM2 port.
Stop pending operations
Read or set a new AutoRange to use.
Read the current atmospheric pressure (on-board barometer).
Read or set the status of the AutoZ automatic zeroing function.
Run AutoZero.
Read or set the on-board barometer calibration
Read or set the configuration of the COM1 port.
Read or set the configuration of the COM2 port.
Enable continuous measurements
Read or set the current date.
Read the last error message.
Read or set the GPIB interface address.
Read or set the fluid head settings.
Read or set the RPM4 alphanumeric asset ID tag.
Selects “classic” program message format
Selects “enhanced” program message format
Read or set the lower limit for the current range (negative gauge and differential
modes only).
Return control to the RPM4 front panel.
Read the power-up memory test status.
Read or change the active measurement mode.
Read or set the type of program message format to use.
Read or set the status of low vent valve (Gxxx or BGxxx Q-RPT only)
Read or set the user Lo Q-RPT calibration information.
Read or set the user Lo Q-RPT calibration information (old command).
Read the next RPM4 pressure.
Read the next RPM4 pressure, rate, and ATM.
Read the last RPM4 pressure, rate and ATM.
Select a Q-RPT to be “active” in it’s default full scale range
Read the next available rate of change of pressure.
Read or set the Q-RPT measurement read rate and mode
Read or set a flag that is cleared by a Not Ready condition.
Enable remote local lockout operation.
Read or set the pressure display resolution for the current Q-RPT and range.
Reset the RPM4 to default user parameters.
Read the available Q-RPT data.
Read or set the front panel screen saver period.
Read or set the SDS state for a specific Q-RPT
Read or set the active Q-RPT SDS state
Read or set the SDS mode for a specific Q-RPT
Read the serial number of the RPM4.
Read the next available pressure status (Ready/Not Ready).
Read or set the stability required for a Ready condition.
Read or set the stability required for a Ready condition (% span/ s).
Read or set the current time of day.
Convert a pressure in Pascal to pressure in the current units.
Read or set the user defined pressure unit.

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RPM4™ OPERATION AND MAINTENANCE MANUALCOMMAND‘n’ indicates anoptional suffix

Read or set the upper limit for the current range.
Read or set the pressure unit of measure for the current range.
Read the RPM4 software version.
Read or set the AutoZero Zoffset for the specified Q-RPT.
Read or set the AutoZ Zoffset for the specified Q-RPT (old command).

ULn
UNITn
VER
ZOFFSETnZOFFSET:XX

4.4.2

DESCRIPTIONERROR MESSAGESS
Table 17. Error #s and Descriptions
REPLY
ERR# 0
ERR# 2
ERR# 3
ERR# 4
ERR# 5
ERR# 6
ERR# 7
ERR# 8
ERR# 9
ERR# 10
ERR# 11
ERR# 12
ERR# 13
ERR# 14
ERR# 17
ERR# 18
ERR# 19
ERR# 20
ERR# 21
ERR# 22
ERR# 23
ERR# 25
ERR# 26
ERR# 27
ERR# 28
ERR# 29
ERR# 30
ERR# 31
ERR# 32
ERR# 37
ERR# 38
ERR# 39
ERR# 45
ERR #46
ERR #52
ERR# 53© 2004-2007 DH Instruments, a Fluke Company

DESCRIPTION“OK”“Text argument is too long”“Arguments cannot be 0”“External device not detected”
Not used“Numeric argument missing or out of range”“Missing or improper command argument(s)”“External device time-out error”“Unknown command”“Missing or invalid command suffix”“Command missing argument”“System overpressured” or “overpressure may result”“Text queue overflow”“User unit not defined”
Not used“Command not yet available”“Not available with absolute units”“Not available with gauge device”
Not used“Pressure is not stable”“Option not available or installed”
Not used“COM port failed to initialize”“Internal device failure”“Device failure”“Device not available”“Must be on range HI”“Exceeds upper or lower limit”“Not stable enough”“Data table is full”“Selected range is not available”“Data verify error”“Argument not allowed”“Argument cannot be negative”“Command obsolete”“Not Available”

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4.4.3

PROGRAM MESSAGE DESCRIPTION OVERVIEW

Each program message description is separated into the following sections:PurposeCommandQuery

Classic

SuffixArguments
Default
Remarks
ExampleErrorsSee Also

A brief description of the programs message’s function.
This is the Enhanced program message syntax to send data to the RPM4 or to execute an
RPM4 function. The RPM4 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 RPM4 using the IEEE-488 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 notlisted in the program message description, then the Command type is not supported whenusing the Enhanced format.
This is the Enhanced program message syntax to request data from the RPM4. The RPM4
must be set to use the enhanced format (see Section 3.5.2.3). The RPM4 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 the Query type forthe program message is not supported when using the Enhanced format.
This is the Classic program message syntax to send data to the RPM4, to execute an
RPM4 function, or to query for data. The RPM4 must be set to use the classic format(see Section 3.5.2.3). The command may be followed by a ‘(=)’ and additional argument
characters to show that argument(s) can be passed. If there are multiple arguments, thencommas must separate them. The RPM4 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.
Some commands support an optional suffix. This suffix is used to specify a Q-RPT to which
the command applies, since many settings are Q-RPT specific:
Suffix of ‘1’ for Hi Q-RPT accessSuffix of ‘2’ for Lo Q-RPT accessSuffix of ‘3’ for HL Q-RPT access.
If an optional suffix is allowed but not given, then the “Active Q-RPT” will be addressed. The“Active Q-RPT” is the Q-RPT that is currently displayed on the top line of the front panel of theRPM4, and is identified by the text label in the upper right of the pressure display screen. The
last Q-RPT ranged or selected using the “RANGE” or “ARANGE” commands is the “Active” QRPT. The “ARANGE”, “RANGE” or “RPT” command query can be used to determine which
Q-RPT is currently active. With the Hi Q-RPT In differential mode of operation, there are some
limitations on access to the Lo Q-RPT, and with the HL Q-RPT there are limitations on accessto both the Hi and the Lo Q-RPTs independently.
If the program message can be used to set data inside the RPM4, then this section describes
the arguments and their limits.
If the program message can be used to set data inside the RPM4, then this line shows(using the enhanced format) the default setting from the factory.
This field has the details and remarks about the command.
Examples are given for the enhanced and classic methods.
Enhanced:
An example of the use of an enhanced format program message to besent to the RPM4 is shown. The message sent to the RPM4 appears after
the “Cmd sent:” label. If only a Query type exists, the “Query sent:”label is shown instead. Directly under this label, “Query reply” shows atypical 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
RPM4 is shown. The command sent to the RPM4 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.
If 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.
Indicates related commands (“----“) and refers to manual sections giving detail on RPM4
operation corresponding to the program message.

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4.4.4#
PurposeClassic
Arguments
Remarks

Example(classic)See Also
ABORT
PurposeCommandClassic
Remarks
Example(enhanced)
Example(classic)See Also

PROGRAM MESSAGE DESCRIPTIONSTo allow the host PC to communicate with a device connected to the RPM4 COM2 port.
“#xx”
xx:
The string to send out of the RPM4 COM2 port. It must be less than
40 characters long.
The RPM4 COM2 port can be used to communicate to another RS232 device (such as
another RPM4). This allows the user to use a single COM port or IEEE-488 port on thehost computer to communicate with the RPM4 and another RS232 device. A carriage
return and a line feed (<CR><LF>) are added to the string.
After this program message is issued, the RPM4 will reply back every string received by
the RPM4 COM2 port that is terminated with a carriage return. Line feeds are discarded.
This will discontinue when the next query is sent to the RPM4.
There is no other reply from this program message. Prior to using this program message,
you must ensure that the RPM4 COM2 port is correctly set up to communicate with thedevice on COM2. Refer to the “COM2=“ program message.
Sent:“#VER”
Reply:“DH INSTRUMENTS, INC RPM4 us A1000/A0015 Ver2.00 ”
This example assumes that a second RPM4’s COM1 port is connected to the RPM4
COM2 port. This example gets the version of the second RPM4.
“COM2”
3.5.2
Cancels any pending data requests by the “PR”, “PRR” “RATE”, “SR” or “CONT”
commands.
“ABORT”“ABORT”
This program message is usually used to ensure the RPM4 is in an idle condition.
Cmd sent:“ABORT”
Reply:“ABORT” (no reply if IEEE-488)
Sent:“ABORT”
Reply:“ABORT”“PR”, “PRR” “RATE”, “SR” or “CONT”
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ARANGEn
PurposeCommandQuery
Classic
Query
Optional Suffix

Arguments

Read or set a new AutoRange range to use.
“ARANGEn Range, unit, mode (,RptLabel)” (set to user defined range)“ARANGE Q-RPTLabel”(set to Q-RPT default range)“ARANGEn?”“ARANGEn= Range, units, mode (,RptLabel)” (set to user defined range)“ARANGE= Q-RPTLabel”(set to Q-RPT default range)“ARANGEn”“n”
A suffix may be used instead of “RptLabel”‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT
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
Measured pressure values are returned with “g” to identify measurementmode for both gauge and negative gauge measurement modes.
One of the Q-RPTs that is available.
“IH”: Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF. HL Q-RPT if
the Hi and Lo Q-RPTs are OFF.
“IL”: Lo Q-RPT“HL”: HL Q-RPT.
The ARANGE command is used to define an RPM4 range by specifying a desired unit ofmeasure, measurement mode and maximum pressure, and have the RPM4 pick the best
available Q-RPT and make adjustments to optimize operation in that range.
The optional suffix or the “RptLabel” argument can be used to specify which Q-RPT you
wish to use for the AutoRange range instead of allowing the RPM4 to pick the best QRPT. By using this option you can override the internal logic that picks the most suitable QQ-RPT. This Q-RPT specified must be valid for the maximum pressure and measurementmode specified.
The reply indicates the current range data, including the Q-RPTLabel used for the range.
If “inWa” is specified for the unit, the temperature reference can be given after the unit
text (“inWa4”, “inWa20” or “inWa60” corresponding to inWa at 4 °C, 20 °C or 60 °F). If nonumber is given, a default of 20 °C is assumed. There is no indication of the temperaturereference in the reply.
If you just specify the Q-RPTLabel without any other arguments, the Q-RPT specified will
become active in it’s last range and settings. The previously set unit and measurementmode for the Q-RPT specified will become active.
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)
Query reply:“250.00 inWa, G, IH”(Lo Q-RPT is used)
Cmd sent:“ARANGE=500, kPa, G(range of 500 kPa in gauge mode)
Query reply:“500.00 kPa, G, IL”(Lo Q-RPT is used)“ARANGE2 50, psi, A(range of 50 psi in absolute mode on
Cmd sent:the Lo Q-RPT)“50.000 psi, A, IL”(No reply if GPIB-488)
Query reply:“ARANGE IH(Hi Q-RPT’s prev range made active)
Cmd sent:“500.000 kPa, A, IH”(No reply if GPIB-488)
Query reply:“Range“ maximum pressure exceeds available Q-RPTs or is negative.
ERR# 6:
RPT specified by the optional suffix is not valid for the current operating
ERR#10:conditions
Cannot Range to ‘0’ with absolute units.
ERR# 19:
Cannot Range to ‘0’ with gauge units.
ERR# 20:
Correct type of Q-RPT for the selected “Mode” is not available.
ERR# 29:
RPT specified is not available.
ERR# 53:“RPT”, “RANGE”, “MMODE”, “UNIT”
3.3.4, .3.2.4, 3.3.3, 3.3.2
RptLabel:(optional)

Remarks

Example(enhanced)
Example(classic)
Example(enhanced)
Example(classic)
Example(enhanced)
Example(enhanced)
ErrorsSee Also

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ATM
Purpose
Query
Classic
Remarks
Example(enhanced)
Example(classic)
ErrorsSee Also
AUTOZEROn
PurposeCommandQuery
Classic
Default
Optional Suffix

Arguments
Remarks

Example(enhanced)
Example(classic)
ErrorsSee Also
AUTOZEROn=RUN
PurposeCommandQuery
Classic
Optional Suffix

Arguments
Remarks

Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also

Reads the next measured pressure from RPM4’s on-board barometer (if present).
“ATM?”“ATM”
The atmospheric pressure as measured by the RPM4 on-board barometer is returned in
the current pressure units of the active Q-RPT (always absolute). This measurement isfollowed by the units text. Not all RPM4s are equipped with an on-board barometer.
Query sent:“ATM?”
Query reply:“97.12348 kPa a”
Sent:
“ATM”
Reply:“97.12384 kPa a”
ERR# 23:
RPM4 is not equipped with a barometer.
3.5.7.1
Read or set the status of the AutoZ function.
“AUTOZEROn state”“AUTOZEROn?”“AUTOZEROn= state”“AUTOZEROn”“AUTOZERO1”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active‘state’:’0’ Autozero OFF’1’ Autozero ON
The RPM4 AutoZ function can be turned ON and OFF. There is a separate AutoZ flag forthe gauge, absolute, and differential measurement modes for each Q-RPT. This
command sets the AutoZ status for the current mode of the specified or the active Q-RPT
only. To set the sate of AutoZ for a measurement mode, you must be in that mode.
Cmd sent:“AUTOZERO 0”
Query reply:“0”(No reply if GPIB-488)
Sent:“AUTOZERO=0”
Query reply:“AUTOZERO=0”
ERR# 7:
The argument was other than ‘0’ or ‘1’.
ERR# 10:The suffix is invalid.
“ZOFFSET”, “MMODE”
3.5.1
Run the AutoZero routine.
“AUTOZEROn RUN (,Pref)”“AUTOZEROn? RUN (,Pref)”“AUTOZEROn= RUN (,Pref)”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active‘Pref’:The AutoZ reference pressure in Pa. Optional when the RPM4 is not in
absolute measurement mode, as the reference is usually “0”.
The RPM4 AutoZ function can be remotely run with this command only if AutoZero is
ON. You should ensure that the pressure is stable for valid determination of Zoffset. If in
differential mode, the previous 5 measurements of the Q-RPTs are averaged for Zoffset
calculation so you should ensure that the RPM4 has been stable for at least 5
measurement cycles before running a remote AutoZ in differential mode.
Cmd sent:“AUTOZERO RUN”
Query reply:“OK”(No reply if GPIB-488)
Cmd sent:“AUTOZERO? RUN, 97283”(abs AutoZero to 97283 Paa)
Query reply:
“OK”
Sent:
“AUTOZERO=RUN”
Query reply:“OK”
An argument was not given for the AutoZ reference in absolute mode.
ERR# 6:
Invalid suffix
ERR# 10:
AutoZero is currently OFF.
ERR# 53“ZOFFSET”, “MMODE”, “AUTOZERO”
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4. REMOTE OPERATIONCALAMB
PurposeCommandQuery
Classic
Defaults
Arguments
Remarks
Example(enhanced)
Example(classic)
ErrorsSee Also
COM1
PurposeCommandQuery
Classic
Arguments

Defaults
Remarks

Example(enhanced)
Example(enhanced)
Example(classic))
ErrorsSee Also
COM2
PurposeCommandQuery
Classic
Arguments

Defaults
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also

Read or set the on-board barometer calibration.
“CALAMB adder, mult, CalDate”“CALAMB?”“CALAMB=adder, mult, CalDate”“CALAMB”“CALAMB = 0.0, 1.0, 19800101”
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”
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.
Cmd sent:“CALAMB? 2.1, 1.000021, 20011201”
Query reply:“
2.10, 1.000021, 20011201”
Sent:“CALAMB=2.1, 1.000021, 20011201”
Reply:“
2.10, 1.000021, 20011201”
ERR# 6:
One of the arguments is out of range.
3.5.7.1, 5.3
Read or set the RS232 settings for the COM1 port.
“COM1 baud, parity, data, stop”“COM1?”“COM1=baud, parity, data, stop”“COM1”Baud:
The baud rate. This may be ‘300’, ‘600’,’1200’,’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’.
“COM1 2400,E,7,1”
The COM1 port is used to communicate to the RPM4. When the COM1 port configuration of theRPM4 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 250ms or longer delay after receiving the reply to this command will ensure that the RPM4 haschanged the COM port settings and is ready for communications at the new settings.
Cmd sent:“COM1 9600,N,8,1”
Query reply:“9600,N,8,1”(No reply if GPIB-488)
Cmd sent:“COM1? 9600,N,8,1”
Query reply:“9600,N,8,1”
Sent:“COM1=9600,N,8,1”
Reply:“9600,N,8,1”
ERR# 7:
Missing or improper program message argument(s).
“COM2”
3.5.2.1
Read or set the RS232 settings for the COM2 port.
“COM2 baud,parity,data,stop”“COM2?”“COM2= baud,parity,data,stop”“COM2”
baud:
The baud rate. This may be ‘300’, ‘600’,’1200’,’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 2400,E,7,1”
COM2 is generally used to allow the host computer to communicate through the RPM4 to an
additional device connected to COM2. This can be useful if the host computer does not have 2
serial ports available.
Cmd sent:“COM2 9600,N,8,1”
Query reply:“9600,N,8,1”(No reply if GPIB-488)
Cmd sent:“COM2? 9600,N,8,1”
Query reply:“9600,N,8,1”
Sent:“COM2=9600,N,8,1”
Reply:“9600,N,8,1”
ERR# 7:
Missing or improper program message argument(s).
“COM1”
3.5.2.1

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RPM4™ OPERATION AND MAINTENANCE MANUAL

CONTn
Purpose
Query
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(classic)See Also
DATE
PurposeCommandQuery
Classic
Arguments
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
ERR
Purpose
Query
Classic
Remarks

Example(enhanced):
Example(classic)See Also

Have the RPM4 reply continuously as each new measurement becomes available.
“CONTn?”“CONTn”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
This command is somewhat different than most as it enables the RPM4 to continuously output the
selected Q-RPT’s measurement without further queries. This continues until the next query is
received by the RPM4, or if the ABORT” or “*CLS” command is received. The frequency of themeasurements is determined by the readrate of the Q-RPT. The data returned includes thepressure of the specified or active Q-RPT, current unit of measure and measurement mode.
Query sent:“CONT1?”
Query reply:“1936.72 kPa a” (repeats every measurement cycle)
Query sent:“CONT”
Reply:“1936.72 kPa a” (repeats every measurement cycle)“PR”, “READRATE”
Read or set the RPM4 date.
“DATE date”“DATE?”“DATE= date”“DATE”
date:
The date in the numerical only format “YYYYMMDD”
The RPM4 has an internal real time calendar clock. The span of acceptable dates ranges
from 19800101 to 20791231. The reply is always in the YYYYMMDD format.
Cmd sent:“DATE 20030115”
Query reply:“20030105”(No reply if GPIB-488)
Cmd sent:“DATE? 20030105”
Query reply:“20030105”
Sent:“DATE=20021201”
Reply:“20021201”
ERR# 6:
Missing or improper program message argument(s).
“TIME”
3.5.5.3
Read the new available error message from the Error Queue.
“ERR?”“ERR”
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. In “classic” mode only the most recent
error can reside in the queue. “OK” is replied if there are no error messages left. If an error occurs inenhanced mode using the IEEE-488 interface, no reply is generated even if the command was aquery.
Query sent:“ERR?”
Query reply:“Numeric argument missing or out of range”
Sent:
“ERR”
Reply:“Numeric argument missing or out of range”
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4. REMOTE OPERATION

GPIB
PurposeCommandQuery
Classic
Defaults
Arguments
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also:
HEAD
PurposeCommandQuery
Classic
Defaults
Arguments

Remarks
Example(enhanced)
Example(classic)
ErrorsSee Also:
ID
PurposeCommandQuery
Classic
Arguments
Remarks

Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also

Read or set the GPIB interface address.
“GPIB addr”“GPIB?”“GPIB=addr”“GPIB”“GPIB 10”Addr:
The address of the IEEE-488 (GPIB) interface (1 to 30)
The GPIB address is changed following the reply of this command. Each device on a GPIB
interface bus requires a unique address.
Cmd sent:“GPIB 21”
Query reply“21”(No reply if GPIB-488)
Cmd sent:“GPIB? 21”
Query reply
“21”
Sent:
“GPIB=21”
Reply:“21”
ERR# 6:
The argument is not within given limits.
3.5.2.2
Read or set the fluid head settings.
“HEAD height, units, fluid”“HEAD?”“HEAD=height, units, fluid”“HEAD”“HEAD 0, cm, N2”
height:
The height of the test in relation to the RPM4. The value is positive if the test is
above the RPM4, or negative if below the RPM4. The value can be between 9999 and 9999. Setting the value to ‘0’ disables the head correction.
units:The height units. This must be “in” or “cm”.
gas:
The fluid type. This must be “N2”, “Air”, “He”, “Oil”, “H2O”, or “User”.
The RPM4 can make a fluid head correction to allow it to display the pressure at a level other than
the reference level of the RPM4.
Cmd sent:“HEAD? 10,in,N2”
Query reply:“10, in, N2”
Sent:“HEAD=10,in,N2”
Reply:“10, in, N2”
The fluid text is too long
ERR# 2:The height is not within given limits or the unit is invalid.
ERR# 6:
The fluid text is invalid
ERR #7:
3.3.7, 3.5.3
Read or set the user defined instrument identification label.
“ID string”“ID”“ID=string”“ID”
String:An alphanumeric string up to 12 characters long.
The user defined ID label can be used to allow the user to “tag” the RPM4 with a unique
identifier. This ID is stored in non-volatile memory and cannot be erased by a power failure,system fault or reset. The ID should not be changed frequently, as the non-volatile memory
may fail after 100,000 write operations.
Cmd sent:“ID RPM4 #A01”
Query reply“RPM4 #A01”(No reply if GPIB-488)
Cmd sent:“ID? RPM4 #A01”
Query reply“RPM4 #A01”
Sent:“ID=RPM4 #A01”
Reply:“RPM4 #A01”
ERR# 2
Text argument is too long (more than 12 characters)
3.5.5.4

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RPM4™ OPERATION AND MAINTENANCE MANUAL

L2 / L3
PurposeCommandDefaults
Remarks
Example(enhanced)
Example(classic)See Also
LLn
PurposeCommandClassic
Optional Suffix

Arguments
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
LOCAL
PurposeCommandClassic
RemarkExample(enhanced)
Example(enhanced)
Example(classic)See Also

Read or set the type of program command format to use (classic or enhanced).
“L2” enables “classic” mode
“L3” enables “enhanced” mode
“L2”
(Classic mode)
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.
Cmd sent:“L3”
Query reply:“L3”(No reply if IEEE-488)
Sent:
“L2”
Reply:“L2”“MSGFMT”
4.3, 3.5.2.3
Read or set the lower pressure limit for the active range and measurement mode (negative
gauge or differential measurement mode only).
“LLn limit”“LLn =limit”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF and the HL
Q-RPT is not active.
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT if the HL Q-RPT is not active and measurementmode is not differential.
‘3’ Specify the HL Q-RPT if the HL Q-RPT is active.
"limit”:
The lower pressure limit for the current pressure range in the specified QRPT’s current unit of measure unit and measurement mode. Value is always
a negative value of gauge pressure.
Negative gauge and differential modes in RPM4 have a lower limit. If the pressure is lessthan the lower limit, the pressure display flashes. This feature should always be used toprevent accidental over (under) pressure of a device under test.
Cmd sent:“LL -4”
Reply:“-4 kPa g”(no reply if IEEE-488)
Cmd sent:“LL? -4”
Reply:“-4 kPa g”
Sent:“LL=-4”
Reply:“-4 kPa g”
The limit argument is invalid.
ERR# 6:The suffix is invalid
ERR# 10The mode must be negative gauge to specify a lower limit.
ERR# 23“UL”, “MMODE”
3.4.4, 3.3.3
Returns control to the RPM4 front panel.
“LOCAL”“LOCAL”
The 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 RPM4 power.
Cmd sent:“LOCAL”
Reply:“LOCAL”(no reply if IEEE-488)
Cmd sent:“LOCAL?”
Reply:“LOCAL”
Sent:“LOCAL”
Reply:“LOCAL”“REMOTE”© 2004-2007 DH Instruments, a Fluke Company

Page 94

4. REMOTE OPERATION

MEM
Purpose
Query
Classic
Remarks
Example(enhanced)
Example(classic)See Also
MMODEnPurposeCommandQuery
Classic

Read the status from the power-up memory test.
“MEM?”“MEM”
The RPM4 system memory stores the user settings (units, resolution) and retains 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 is set to reflect this.
Query sent:“MEM?”
Reply:“0” RPM4 data corrupted and was set to factory defaults.
“1” The memory was found to be OK on power-up.
Sent:
“MEM”
Reply:“MEM=0” RPM4 data corrupted and was set to factory defaults.
“MEM=1” The memory was found to be OK on power-up.
3.5.9, 3.5.7.5

Optional Suffix

Read or change the active measurement mode.
“MMODEn mode”“MMODEn?”“MMODEn=mode”“MMODEn ”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF and the HL
Q-RPT is not active.
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT if the HL Q-RPT is not active and measurementmode is not differential.
‘3’ Specify the HL Q-RPT if the HL Q-RPT is active.

Arguments

Mode:

"A"
"G"
"N"
“D”

Absolute mode
Gauge mode
Negative gauge mode
Differential mode (available only for the Hi Q-RPT)
Measured pressure values are returned with “g” to identify measurementmode for both gauge and negative gauge measurement modes. Differential
mode restricts access to settings on the Lo Q-RPT.

Remarks
Example(enhanced)
Example(enhanced)
Example(enhanced)
ErrorsSee Also

The measurement mode can also be set using the “UNIT” command but the “UNIT” command
does not distinguish between gauge and negative gauge in it’s reply, while the “MMODE”
does. Measurement mode is range specific.
Cmd sent:“MMODE A”
Query reply:“A”(No reply if IEEE-488)
Cmd sent:“MMODE? A”
Query reply:“A”
Cmd sent:“MMODE=G”
Query reply:“G”
Invalid argument text.
ERR# 6:
Abs mode only with altitude units or gauge mode only with gauge Q-RPT.
ERR# 7:The suffix indicating the Q-RPT is invalid for the current conditions.
ERR#10:Absolute or negative gauge mode not available with gauge Q-RPT.
ERR# 20:
Absolute Q-RPT with an absolute and negative gauge OFF calibration.
The current range cannot support gauge mode.
Gauge mode range would be negative.
ERR# 53:
Lo Q-RPT not suitable for differential mode.
“UNIT”, “ARANGE”
3.3.3

Page 95© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUALMSGFMT
PurposeCommandQuery
Classic
Arguments
Defaults
Remarks

Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
NVENTnPurposeCommandQuery
Classic
Default
Optional Suffix

Arguments
Remarks

Example(enhanced)
Example(enhanced)
Example(classic)See Also

Read or set the type of program command format to use (enhanced or classic).
“MSGFMT mode
“MSGFMT?”“MSGFMT= mode
“MSGFMT”
mode:‘1’ to use the enhanced command format.
‘0’ to use the classic command format.
“MSGFMT 0”
The user can select the type of remote command format to use. This format must agree with theformat sent to the RPM4
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).
It is recommended to use the “L2” and “L3” commands instead of this command for new designs.
Cmd sent:“MSGFMT 1”
Query reply:“1”(No reply if IEEE-488)
Cmd sent:“MSGFMT? 1”
Query reply:
“1”
Sent:
“MSGFMT=1”
Reply:“MSGFMT=1”
ERR# 6:
Missing or improper program message argument(s).
“L2 / L3”
4.3, 3.5.2.3
Read or set the status of low (negative) vent valve (Gxxx or BGxxx Q-RPT only)“NVENTn mode”“NVENTn?”“NVENTn= mode”“NVENTn”“NVENTn AUTO”“n”
The active Q-RPT is assumed if no suffix is given. The “Hi” Q-RPT is assumed if the
HL Q-RPT is active and no suffix is given.
‘1’ Specify the Hi Q-RPT‘2’ Specify the Lo Q-RPT
Mode:’0’ to close the low vent valve.
’1’ to open the low vent valve.
‘AUTO’ for the RPM4 to automatically open and close the low vent valve.
Gxxx or BGxxx Q-RPTs each have a low vent valve that is used to vent the TEST(-) port.
This valve is normally controlled automatically depending on current RPM4 operation but it canbe commanded to open or close using the “NVENT” command.
The reply includes two fields. The first indicates the low vent status. The second indicates
whether the low vent function is AUTO or MANUAL
Cmd sent:“NVENT? 0”
Query reply:“0, MANUAL”
Cmd sent:“NVENT? AUTO”
Query reply:“1, AUTO”
Sent:“NVENT=1”
Query reply:“0, MANUAL”
3.5.7.4© 2004-2007 DH Instruments, a Fluke Company

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4. REMOTE OPERATION

PCALn
PurposeCommandQuery
Classic
Defaults
Optional Suffix

Arguments

Remarks

Example(enhanced)
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
PRn
Purpose
Query
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(classic)See Also

Read or set the calibration information for the Hi or Lo Q-RPT.
“PCALn adder, mult, CalDate”“PCALn?”“PCALn= adder, mult, CalDate”“PCALn”“PCALn = 0.0, 1.0, 19800101”“n”
The active Q-RPT is assumed if no suffix is given. The Hi Q-RPT is assumed if the HL
Q-RPT is active and no suffix is given.
‘1’ Specify the Hi Q-RPT‘2’ Specify the Lo Q-RPT
Adder:The Q-RPT calibration adder (PA). In Pascal.
Mult:
The Q-RPT calibration multiplier (PM) from 0.1 to 100.
CalDate:The date of the calibration in the format “YYYYMMDD” by default. Any otherformat up to 8 characters long is also accepted, and the replied format is in th
previously entered format.
The user defined pressure calibration information for the specified Q-RPT (Hi or Lo) can beaccessed with this program message. The HL Q-RPT does not have it’s own calibration
information. Using this program message overwrites the current calibration coefficients, so caution
must be used. Changes made using this program message take effect immediately.
For compatibility with the obsolete style PPC3 “PCAL:HI” and “PCAL:LO” commands, “:HI” and“:LO” can be used in place of the suffix “n” but this is not recommended for new applications.
Cmd sent:“PCAL2? 2.1, 1.000021, 20011201”
Query reply:“ 2.10 Pa, 1.000021, 20011201” (No reply if GPIB-488)
Cmd sent:“PCAL? 2.1, 1.000021, 20011201”
Query reply:“ 2.10 Pa, 1.000021, 20011201”
Cmd sent:“PCAL:HI? 2.1, 1.000021, 20011201” (PPC3 style is OK)
Query reply:“ 2.10 Pa, 1.000021, 20011201”
Sent:“PCAL1=2.1, 1.000021, 20011201”
Reply:“ 2.10 Pa, 1.000021, 20011201”
ERR# 6:
One of the arguments is out of range.
ERR# 10:The suffix is invalid.
5.2
Read the next available pressure measurement.
“PRn?”“PRn”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
The next available pressure value for the specified or active Q-RPT is read in the current pressure
units. The data returned also contains Ready/Not Ready information, and the pressure unit ofmeasure and measurement mode.
The reply field is always 20 characters long. The first 3 characters of the reply are reserved for the
ready status. The ready status is described in the “SR” program message. The pressure value andpressure unit of measure are right justified in this field.
After receiving this program message, the RPM4 replies back with the data after a new pressure
measurement cycle is complete. This can take up to the current read rate period (1.2 seconds bydefault).
Query sent:“PR?”
Query reply:“R
1936.72 kPa a”
Query sent:“PR”
Reply:“R
1936.72 kPa a”“PRR”, “QPRR”, “SR”, “ABORT”, “READRATE”
3.1.1, 3.2.1, 3.5.7.2

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RPM4™ OPERATION AND MAINTENANCE MANUAL

PRR
Purpose
Query
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(classic)See Also
QPRR
Purpose
Query
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(classic)See Also

Read the next available Ready condition, pressure measurement, rate and on-board
barometer reading.
“PRR?”“PRR”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
The next available Ready condition, Q-RPT pressure measurement, rate of pressure change,
and barometric pressure is replied in the current pressure unit of measure. . This can take up
to the current read rate period (1.2 seconds by default). Each data field is separated by acomma, and is returned in the following order:
ready, pressure UNITS, rate UNITS/s, atm UNITS
Here are the field descriptions:ready:
Three character ready status field. Refer to the “SR” command.
pressure:
The measured pressure for the active Q-RPT 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 in the current
pressure unit per second. This is followed by the current pressure unit of measure.
atm:
The pressure measured by the RPM4 on-board barometer in the current
pressure unit (and always absolute). This is followed by the current pressure
unit. Not all RPM4s are equipped with an on-board barometer. This field is
missing if the RPM4 is not equipped with an on-board barometer.
Query sent:“PRR?”
Query reply:“R,2306.265 kPaa,0.011 kPa/s,97.000 kPa a”“R,2306.265 kPaa,0.011 kPa/s”(no barometer)
Query sent:“PRR”
Reply:“R,2306.265 kPaa,0.011 kPa/s,97.000 kPa a”“PR”, “QPRR”, “SR”
3.1.1, 3.2.1, 3.5.7.1
Read the last Q-RPT pressure measurement, pressure rate and on-board barometer output
immediately.
“QPRR?”“QPRR”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
The last measured Ready/Not Ready condition, active Q-RPT pressure measurement, rate ofpressure change, and barometric pressure is replied in the current pressure unit of measure
immediately. This program message is useful when a rapid response of measured pressure
is needed. It does not result in quicker pressure measurements. Each data field is separated
by a comma, and is returned in the following order:
Ready, pressure UNITS, rate UNITS/s, atm UNITS
Here are the field descriptions:ready:
Three character ready status field. Refer to the “SR” command.
pressure:
The measured pressure for the selected Q-RPT in the current pressure unit.
This is followed by the current pressure unit and measurement mode.
rate:
The measured rate of pressure change for the active Q-RPT in the current
unit of pressure per second. This is followed by the current pressure unit.
atm:
The pressure measured by the RPM4 on-board barometer in the current
pressure unit (but always absolute). This is followed by the current pressure
unit. Not all RPM4s are equipped with an on-board barometer. This field is
missing if the RPM4 is not equipped with a barometer.
Query sent:“QPRR?”
Query reply:“R,2306.265 kPa a,0.011 kPa/s,97.000 kPa a”“R,2306.265 kPa a,0.011 kPa/s” (no barometer)
Query sent:“QPRR”
Reply:“R,2306.265 kPa a,0.011 kPa/s,97.000 kPa a”“PR”, “PRR”, “SR”
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4. REMOTE OPERATIONRANGE
PurposeCommandQuery
Classic
Default

Remarks

Example(enhanced)
Example(classic)
Example(classic)
ErrorsSee Also
RATEn
Purpose
Query
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(classic)See Also

Change the active range to the default range of the Hi, Lo or HL Q-RPT. Replies the active
range full scale, pressure unit and measurement mode.
“RANGE Rng”
“RANGE?”“RANGE= Rng”
“RANGE ”“RANGE IH”
Rng:“IH” for the Hi Q-RPT“IL” for the Lo Q-RPT“HL” for the HL Q-RPT
The active Q-RPT must be selected before making changes to settings that are dependent on therange. Q-RPTs selected with this command are used with their full default pressure range. The reply
indicates the active range in psi if the RPM4 is a “US” version or in kPa if the RPM4 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).
Cmd sent:“RANGE? IL”(select internal Lo Q-RPT in it’s full default range)
Query reply:“2.2 psi g,IL”
Sent:“RANGE= IH”(select internal Hi Q-RPT in it’s full default range)
Reply:“1000 psi a, IH”
Sent:“RANGE”(request current range)
Reply:“220 psi a,IL”
ERR# 6:
Invalid Rng argument.
ERR# 29:
The selected Q-RPT is not available.
“ARANGE”, “RPT”
3.2.3, 3.3.1, 3.3.4
Read the next available pressure rate of change.
“RATEn?”“RATEn”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
The next available pressure rate of change in the current pressure unit per second is returned.
After receiving this program message, the RPM4 replies back with the data once a new pressure
measurement cycle is complete. This can take up to the current read rate period (1.2 seconds
by default).
Query sent:“RATE?”
Query reply:“0.01 kPa/s”
Sent:“RATE2”
Reply:“0.03 kPa/s”“PRR”, “QPRR”.”READRATE”
3.3.6.2

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RPM4™ OPERATION AND MAINTENANCE MANUALREADRATEn
PurposeCommandQuery
Classic
Optional Suffix

Arguments
Remarks

Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
READYCKn
PurposeCommandQuery
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(enhanced)
Example(enhanced)
Example(classic)
Example(classic)
ErrorsSee Also

Read or set the specified or active Q-RPT read rate or auto read rate mode.
“READRATEn period”“READRATEn?”“READRATEn= period”“READRATEn”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF and the HL
Q-RPT is not active.
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT if the HL Q-RPT is not active and measurementmode is not differential.
‘3’ Specify the HL Q-RPT if the HL Q-RPT is active.
“period ":Period to integrate the measurement over (ms). Can be from 200 ms to 20000
ms. Set to ‘0’ to enable automatic read rate.
The RPM4 can have the speed in which it integrates each measurement (“read rate”) automaticallyadjusted based on the rate, or it can manually set to a fixed period. Increasing the read rate increases
the reply time for pressure and rate queries. In differential mode and when using the HL Q-RPT, the Lo
Q-RPT read rate is always set to the same read rate as the Hi.
Cmd sent:“READRATE 1000”
Query reply:“1000”(No reply if GPIB-488)
Cmd sent:“READRATE? 1000”
Query reply:“1000”
Sent:“READRATE=1000”
Reply:“1000”
ERR# 6:The “period” argument is out of range.
ERR#10:The suffix ‘n’ is invalid“PR”, “PRR”, “SR”
3.5.7.2
Read or set the Ready check flag.
“READYCKn 1”“READYCKn?”“READYCKn=1”“READYCKn”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
The internal ready check flag is cleared whenever the specified or active Q-RPT 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 Q-RPT is in a Ready condition.
The “READYCK” program message query can then be used at a later time to determine
whether a Not Ready condition has occurred since the ready check flag was set.
Cmd sent:“READYCK1 1”
Query reply:“1” (no reply if GPIB-488)
Cmd sent:“READYCK1?”
Query reply:“1”
Cmd sent:“READYCK?”
Query reply:“1” (if Q-RPT condition has stayed Ready)“0” (if Q-RPT condition has NOT stayed Ready)
Sent:“READYCK=1”
Query reply:“READYCK=1”
Sent:“READYCK”
Query reply:“READYCK=1” (if Q-RPT condition has stayed Ready)“READYCK=0” (if Q-RPT condition has NOT stayed Ready)
ERR# 6:
Argument is not a ‘0’ or a ‘1’.
“SR”
3.2.1

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4. REMOTE OPERATIONREMOTE
PurposeCommandClassic
Remarks

Example(enhanced)
Example(enhanced)
Example(classic)See Also
RESn
PurposeCommandQuery
Classic
Default
Optional Suffix

Arguments
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
RESET
PurposeCommandClassic
Remarks

Example(enhanced)
Example(enhanced)
Example(classic)See Also

Lock out the front panel keypads during remote operation.
“REMOTE”“REMOTE”
The RPM4 goes into remote mode whenever communications take place. The user canreturn to local operation by pressing the [ESC] key. The REMOTE program message locks
out the front panel completely. The only way to unlock the front panel after the “REMOTE”
command is using the “LOCAL” program message, the IEEE-488 “GTL” command, or bycycling the RPM4 power.
Cmd sent:“REMOTE”
Reply:“REMOTE” (no reply if IEEE-488)
Cmd sent:“REMOTE?”
Reply:“REMOTE”
Sent:“REMOTE”
Reply:“REMOTE”“LOCAL”
To read or set the pressure display resolution for the active range.
“RESn res”
“RESn”“RESn= res”
“RESn”“RESn=0.001”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
The pressure display resolution in % span of the specified Q-RPT range (0.0001 to 1 %FS).
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.
Cmd sent:“RES .01”
Query reply:“0.01” (No reply if GPIB-488)
Cmd sent:“RES? .01”
Query reply:“0.01”
Sent:“RES=.01”
Reply:“0.01”
ERR# 6
The argument is invalid.
3.4.2
res:

Reset the user’s settings to factory defaults.
“RESET”“RESET”
The RPM4 has user settings (units, resolution, etc.) that can be reset to factory defaults. The
remote “RESET” program message corresponds to the front panel “Reset - Sets”. Systemcalibration coefficients and communications settings are not affected. The reset cycle takes up
to 3 seconds to complete. Remote communications should not take place during this period.
Cmd sent:“RESET”
Reply:“RESET”(no reply if IEEE-488)
Cmd sent:“RESET?”
Reply:“RESET”
Sent:“RESET”
Reply:“RESET”
3.5.9.1

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RPM4™ OPERATION AND MAINTENANCE MANUAL

RPTn
Purpose
Query
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(classic)
ErrorsSee Also
SDSn
PurposeCommandQuery
Classic
Default
Optional Suffi

Arguments
Remarks

Example(enhanced)
Example(classic)
ErrorsSee Also

Read the available Q-RPT identification data.
“RPTn”“RPTn”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
Up to two (three including the HL Q-RPT which is a combination of the Hi and Lo) internal QRPTs can be available for use in an RPM4. You can query the RPM4 for information about
each particular Q-RPT. The Q-RPT data is returned in the following format:
RPTLabel, Q-RPTLocator, Serial#, RngGa, RngAbs, Q-RPTMode
RngLabel:
RPT type label. This label identifies the Q-RPT type and range. This is
the same label used on the RPM4 front panel screen.
RptLocator:
Text field identifying the Q-RPT position in the RPM4 system.
“IH” identifies this as an internal, Hi Q-RPT“IL” identifies this as an internal, Lo Q-RPT
Serial#:The serial number of the Q-RPT.
RngGa:The Q-RPT default gauge mode range in the current pressure unit.
RngAbs:The Q-RPT default absolute mode range in the current pressure unit.
“NONE” appears in the field if the Q-RPT is a Gxxx, BGxxx or Axxx withabsolute 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 gaugemeasurement modes.
Cmd sent:“RPT2?”(Get information on the Lo Q-RPT)
Query reply:“A350K, IL, 82345, 35, 50,A”
Cmd sent:“RPT3”(Get information on the HL Q-RPT)
Query reply:“A7M, HL, 82345, 1000, 1000,A”
ERR#4:
External device not detected.
ERR# 10:Invalid suffix.
3.2.3, 3.2.4
Read or set the OPEN/CLOSE status for the specified or active Q-RPT SDS systems. Thisis equivalent to use of the SDS temporary OPEN/CLOSE function from the RPM4 front panel.
“SDSn close”“SDSn”“SDSn=close”“SDSn”“SDSn=1”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT’s SDS if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT’s SDS if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT’s SDS.
‘3’ Specify the HL Q-RPT’s SDS if the HL Q-RPT is active”close”:‘0’ to OPEN the SDS system.
‘1’ to CLOSE the SDS system.
Each Q-RPT of designation A7M or less can have an “SDS” system, which can be either“OPEN” or “CLOSED”. This command allows access to each one without affecting the other,regardless of whether the SDS for the selected Q-RPT is currently full time “ON” or “OFF”.
Caution must be used in differential mode or when using the HL Q-RPT, as this command
can allow you to have one Q-RPT open while the other Q-RPT is closed. If the “HL” Q-RPT
SDS is specified, then both the Hi and the Lo Q-RPT SDS will be affected. This command
does not affect the power up status of the SDS system.
Cmd sent:“SDS2? 1”(close the Lo Q-RPT SDS)
Query reply:“1”
Cmd sent:“SDS1=0”(open the Hi Q-RPT SDS)
Query reply:“SDS1=0”
Argument not a ‘0’ or a ‘1’
ERR# 7:
Invalid suffix.
ERR# 10:
SDS not installed on this Q-RPT and pressure is close to ATM.
ERR# 23:
SDS not installed on this Q-RPT and pressure not close to ATM.
ERR# 53:“SDSAUTO”, “SDSACT”
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4. REMOTE OPERATIONSDSACT
PurposeCommandQuery
Classic
Default
Arguments
Remarks

Example(enhanced)
Example(classic)
ErrorsSee Also
SDSAUTOn
PurposeCommandQuery
Classic
Default
Optional Suffix

Arguments
Remarks
Example(enhanced)
Example(classic)
ErrorsSee Also
SCRSAV
PurposeCommandQuery
Classic
Arguments
Default
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also

Read or set the status for both the Hi and Lo Q-RPT’s SDS systems. This is equivalent touse of the [SDS] key from the RPM4 front panel.
“SDS state”“SDS”“SDS=state”“SDS”“SDS=1””state”:‘0’ OPEN the SDS system on the active Q-RPT and CLOSE the SDS
system on the “inactive” Q-RPT.
‘1’ to CLOSE the SDS system on both Q-RPTs.
This command can be used to select one Q-RPT at a time, ensuring that the “inactive” Q-RPT
SDS is closed. If a Q-RPT’s SDS is full time “OFF”, then it is not be affected by thiscommand. The status of the active Q-RPT’s SDS system is replied. If the RPM4 is indifferential mode or the HL Q-RPT is active, then this command opens or close both the Hi
and Lo SDS at the same time, unless the SDS is full time “off”.
Cmd sent:“SDS? 1”
Query reply:“1”
Cmd sent:“SDS=0”
Query reply:“SDS=0”
Argument not a ‘0’ or a ‘1’
ERR# 7:
Invalid suffix or command argument.
ERR# 10:
SDS not installed on this Q-RPT
ERR# 23:“SDSAUTO”, “SDS”
3.2.7, 3.3.8, 3.5.4
Read or set the automatic full time ON/OFF status for the specified or active Q-RPT SDS
systems. This is equivalent to use of the SDS full time ON/OFF function from the RPM4
front panel.
“SDSAUTOn on”“SDSAUTOn”“SDSAUTOn=on”“SDSAUTOn”“SDSAUTOn=1”“n”
The active Q-RPT is assumed if no suffix is given. If the “HL” Q-RPT is the active QRPT, and no suffix is specified, then the “Hi” Q-RPT is assumed‘1’ Specify the Hi Q-RPT SDS‘2’ Specify the Lo Q-RPT SDS” on”:‘0’ to turn the SDS system OFF.
‘1’ to turn the SDS system ON
Turning an SDS system to full time “OFF” or “ON” affects how the remote command“SDSACT” and the front panel SDS button can affect each Q-RPT’s SDS system.
Cmd sent:“SDSAUTO2? 1”
Query reply:“1”
Cmd sent:“SDSAUTO1=0”
Query reply:“SDSAUTO1=0”
Argument not a ‘0’ or a ‘1’
ERR# 7:
Invalid suffix.
ERR# 10:
SDS not installed on this Q-RPT
ERR# 23:“SDSACT”, “SDS”
3.2.7, 3.3.8, 3.5.4,
Read or set the front panel display screen saver activation time.
“SCRSAV n”“SCRSAV?”“SCRSAV=n”“SCRSAV”n:
The inactivity period (0 – 99 minutes) after which screen saver activates.
“SCRSAV 10”
The RPM4 front panel will dim after a period of keyboard and remote inactivity. Setting thisvalue to ‘0’ disables this feature.
Cmd sent:“SCRSAV 30”
Query reply:“30”(No reply if GPIB-488)
Cmd sent:“SCRSAV? 30”
Query reply:
“30”
Sent:
“SCRSAV=30”
Reply:“30”
ERR# 6
The argument was invalid.
3.5.5.1

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SN
Purpose
Query
Classic
Remarks
Example(enhanced)
Example(classic)See Also
SR
Purpose
Query
Classic
Optional Suffix

Remarks

Example(enhanced)
Example(classic)See Also
SS%n
PurposeCommandQuery
Classic
Optional Suffix

Arguments
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also

To read the serial number of the RPM4.
“SN?”
“SN”
The RPM4 is serialized. The serial number can be read using this program message.
Query sent:“SN?”
Query reply:
“321”
Sent:
“SN”
Reply:“321”
3.5.5.4
Read the next available Ready/Not Ready status.
“SR?”
“SR”
“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
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 stability criterion.
“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 orlower 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.
Query sent:“SR?”
Query reply:
“NR”
Sent:
“SR”
Reply:“NR”“PR”, “PRR”, “HS”, “SS”, “UL”, “LL” Commands
3.2.1, 3.4.4, 3.4.4.1
Read or set the current stability limit as a % of range.
“SS% limit”“SS%?”“SS%=limit”
“SS%”
“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
limit:The stability limit in %FS of the current active range.
The stability limit can be read and set as a percent of the full scale range of the Q-RPT range.
Cmd sent:“SS% .1”
Query reply:“0.10 %”(No reply from GPIB-488)
Cmd sent:“SS%? .1”
Query reply:“0.10 %”
Sent:
“SS%=.1”
Reply:“0.10 %”
ERR# 6:
The argument was invalid.
ERR# 10:Invalid or missing command suffix.
“SS”
3.4.3

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4. REMOTE OPERATION

SSn
PurposeCommandQuery
Classic
Optional Suffix

Arguments
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
TIME
PurposeCommandQuery
Classic
Arguments
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also
UCOEFnPurpose
Query
Classic
Optional Suffix

Remarks
Example(enhanced)
Example(classic)See Also

Read or set the current pressure stability limit.
“SS limit”“SS?”“SS=limit”“SS”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
Limit:The stability limit in the current pressure unit of measure.
The stability limit can be read and set as a pressure. The stability limit is used as theReady/Not Ready criteria..
Cmd sent:“SS .1”
Query reply:“0.10 kPa/s”(No reply from GPIB-488)
Cmd sent:“SS? .1”
Query reply:“0.10 kPa/s”
Sent:“SS=.1”
Reply:“0.10 kPa/s”
ERR# 6:
The argument was invalid.
ERR# 10:Invalid or missing command suffix.
“SS%”
3.4.3
Read or set the RPM4 internal clock.
“TIME hh:mmXX”“TIME?”“TIME=hh:mmXX”“TIME”
hh:mm:The time in a 12 hour format using a colon delimiterXX:”am” or “pm”
Cmd sent:“TIME 12:52PM”
Query reply:“12:52pm”(No reply if GPIB-488)
Cmd sent:“TIME? 12:52PM”
Query reply:“12:52pm”
Sent:“TIME=12:52PM”
Reply:“12:52pm”
ERR# 7:
Missing or improper program message argument(s).
“DATE”
3.5.5.3
To identify the coefficient used to convert 1 Pascal to the current pressure unit of measure.
“UCOEFn?”“UCOEFn”“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT‘3’ Specify the HL Q-RPT if the HL Q-RPT is active
The RPM4 handles all pressure values internally in Pascal. The coefficient replied isequivalent of 1 Pa in the current pressure unit of measure. This program message allows theuser to convert pressures
Query sent:“UCOEF?”
Query reply:“0.0010000000”
Sent:“UCOEF”
Reply:“0.0010000000”
3.3.2, 3.5.6, 7.2.1

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UDU
PurposeCommandQuery
Classic

Default
Remarks
Example(enhanced)
Example(enhanced)
Example(enhanced)
ErrorsSee Also
ULn
PurposeCommandQuery
Classic
Optional Suffix

Arguments
Remarks
Example(enhanced)
Example(enhanced)
Example(classic)
ErrorsSee Also

Read or set the user defined pressure unit.
“UDU label, ucoef”“UDU?”“UDU=label, ucoef”“UDU”
label:
User unit label (4 alphanumeric char maximum). It cannot be an alreadysupported unit label.
Ucoef:“User unit conversion coefficient (units/Pa).
“UDU USER,1.0”
The user defined unit must be set up with the program message prior to remote or local
selection.
Cmd Sent:“UDU MYUN, .001”
Query reply:“MYUN, 0.001000”(No reply if GPIB-488)
Cmd Sent:“UDU? MYUN, .001”
Query reply:“MYUN, 0.001000”
Sent:“UDU=MYUN, .001”
Reply:“MYUN, 0.001000”
3.5.6, 3.3.2
Read or set an upper limit for the specified or active Q-RPT.
“Uln limit”“Uln?”“Uln=limit”
“ULn”
“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF and the HL
Q-RPT is not active.
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT if the HL Q-RPT is not active and measurementmode is not differential.
‘3’ Specify the HL Q-RPT if the HL Q-RPT is active.
“limit":The upper limit pressure in the specified Q-RPT’s current pressure unit andmeasurement mode. If the unit is meters, this value is be interpreted in kPa. If
the unit is feet, this value is be interpreted in psi.
The RPM4 has an upper limit for each range and for each measurement mode (gauge, absolute, anddifferential). If the pressure does exceed the upper limit, the pressure display flashes. Thisfeature should always be used to prevent accidental over pressure of a device under test.
Cmd sent:“UL 1000”
Query reply:“1000.00 kPa a” (No reply if GPIB-488)
Cmd sent:“UL? 1000”
Query reply:“1000.00 kPa a”
Sent:“UL=1000”
Reply:“1000.00 kPa a”
ERR# 6:The “limit” argument is out of range.
“LL”
3.4.4

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4. REMOTE OPERATION

UNITn
PurposeCommandQuery
Classic

Optional Suffix

Arguments

Remarks

Example(enhanced)

Example(enhanced)
Example(classic)
ErrorsSee Also
VER
Purpose
Query
Classic
Remarks
Example(enhanced)
Example(classic)See Also

Read or set the pressure unit of measure unit and measurement mode.
“UNITn unit (, ref”)”“UNITn unitn (, ref”)”“UNITn unitg (, ref”)”“UNITn unita (, ref”)”“UNITn unitd (, ref”)”“UNITn?”“UNITn=unit (, ref”)”“UNITn=unitn (, ref”)”“UNITn=unitg (, ref”)”“UNITn=unita (, ref”)”“UNITn=unitd (,ref”)”“UNITn”
The active Q-RPT is assumed if no suffix is given.
“n”‘1’ Specify the Hi Q-RPT if the Hi and Lo Q-RPTs are NOT OFF and the HL
Q-RPT is not active.
Specify the HL Q-RPT if the Hi and Lo Q-RPTs are OFF‘2’ Specify the Lo Q-RPT if the HL Q-RPT is not active and measurementmode is not differential.
‘3’ Specify the HL Q-RPT if the HL Q-RPT is active.
Unit:
The text corresponding to the pressure unit of measure. A unit modecharacter can optionally be added to the end of the units:‘a’ for absolute measurement mode.
‘g’ for gauge measurement mode.
‘n’ for negative gauge measurement mode.
‘d’ for differential measurement mode (Hi Q-RPT only)ref:
The optional unit reference temperature only if the unit is “InWa”
This program message determines what unit of measure and what measurement mode is used todisplay pressure values. Refer to Table 13 for a detailed list of the units available and their labels.
If the unit text is not followed by an explicit mode character (‘a’, ‘g’, ‘n’ or ‘d’) then “gauge” mode isassumed. There can be a space between the unit text and the ‘a’, ‘g’, ‘n’ or ‘d’.
If the unit specified is “InWa”, an optional second argument “ref” can be set. The “ref” can be 4, 20,
or 60 corresponding to InWa at 4 °C, 20 °C or 60 °F. If this second argument is not given when
the unit is “InWa”, then the reference temperature is assumed to be 20 °C. This can also be added
directly onto the end of the Unit argument if desired.
The fifth character of the reply is always ‘a’ for absolute mode, ‘g’ for gauge/negative gauge modeor ‘d’ for differential mode. White spaces precede this character if needed. The temperaturereference is added to the reply only if the unit is “InWa”.
The reply includes the measurement mode character in the fifth position, with an ‘a’ indicating
absolute mode, a ‘g’ indicating gauge or negative gauge mode or a ‘d’ indicating differential mode.
The “MODE” command can also be used to set the desired measurement mode only.
“UNIT? kPaa”
Cmd sent:“kPaa”
Query reply:“UNIT? InWag, 4”
Sent:“inWag, 4”Query reply:“UNIT? InWaa60”
Sent:“inWaa, 60”
Query reply:
Cmd sent:“UNIT psi n”
Query reply:“psi g”(‘g’ used to indicate both gauge & neg gauge modes)“UNIT=kPaa”
Sent:“kPaa”
Reply:“UNIT=InWag, 4”
Sent:“inWag, 4”
Reply:The unit is invalid.
ERR# 7:
The ref is invalid.
ERR# 6:
Absolute measurement mode and altitude units are not allowed with a gauge Q-RPT.
ERR# 20:“MMODE”, “MODE”
3.3.2, 3.3.3, 3.5.6, 7.2.1
Identify the RPM4, US or SI units, the Q-RPT labels and the software version.
“VER?”“VER”
The software version of the RPM4 can be read. This is useful for checking for the presence of theRPM4 and for reference purposes. It indicates the internal Q-RPT(s) and software version.
Query sent:“VER?”
Query reply:“DH INSTRUMENTS, INC RPM4 us A350K/BG15K Ver1.00 ”
Query sent:“VER?”
Query reply:“DH INSTRUMENTS, INC RPM4 us A350K/BG15K Ver1.00 ”“ID”, “*IDN?”
None

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RPM4™ OPERATION AND MAINTENANCE MANUALZOFFSETn
PurposeCommandQuery
Classic
Defaults
Optional Suffix

Arguments

Remarks

Example(enhanced)
Example(classic)
ErrorsSee Also

4.5

Read or set the AutoZ pressure offset (Poffset) for the specified or active Q-RPT in the current
measurement mode.
“ZOFFSETn GaOffset , AbsOffset , DifOffset”“ZOFFSETn?”“ZOFFSETn =GaOffset , AbsOffset , DifOffset”“ZOFFSETn”“ZOFFSETn = 0.0, 0.0, 0.0”
(Gauge Q-RPT)“ZOFFSETn = 101325, 0.0, 0.0” (Absolute Q-RPT)“n”
The active Q-RPT is assumed if no suffix is given.
‘1’ “:HI”
Specify the Hi Q-RPT‘2’ “:LO” Specify the Lo Q-RPT
GaOffset:
The Q-RPT pressure offset (“Poffset”) for Gauge measurement mode (Pa).
AbsOffset:
The Q-RPT pressure offset for absolute measurement mode (Pa)DifOffset:
The Q-RPT pressure offset for differential measurement mode (Pa)The pressure offset (Poffset) for the specified Q-RPT (Hi or Lo) can be accessed with thisprogram message. There are separate offsets for gauge, absolute and differential
measurement modes, but not all modes apply in all cases. Gauge Q-RPTs do not support“AbsOffset”. “DifOffset” applies only to the “Hi” Q-RPT.
Using this program message overwrites the current offset, so caution must be used.
Changes made using this program message take effect immediately.
Cmd sent:“ZOFFSET1 2.1, 0, 0”
Query reply:“ 2.10 Pa, 0.00 Pa, 0.00 Pa”
Sent:“ZOFFSET=97293.1, 3.02, 0”
Reply:“ 97293.10, 3.02, 0.00”
ERR# 6:
One of the arguments is out of range.
3.5.1

STATUS REPORTING SYSTEMThe RPM4 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
RPM4 can be programmed to respond to various status conditions by asserting the SRQ of the IEEE-488
interface. The COM1 port cannot be supported in such a way, so polling must be used.

4.5.1

ERROR QUEUEThe RPM4 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.

4.5.2

STATUS BYTE REGISTERThe RPM4 contains an 8 bit Status Byte Register that reflects the general status of the
RPM4.
Table 18. 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 RPM4 reply output queue, the Error Queue, the Standard
Event Status register and the Ready Event Status register.

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4. REMOTE OPERATION

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
HI
(4)

NRDY
HI
(2)

RDY
HI
(1)

N/A
(8)
ERROR
(4)

Ready Event Status Register(“RSR?” or ” RSE n”)

N/A
(2)
RSR
(1)

←←←

N/A
(128)

MEAS
HI
(64)

NDRY
HI
(32)

RDY
LO
(16)

N/A
(8)

Figure 6. 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
RQS

MSS

ESB

MAV

ERROR

RSR

N/A Bit 7 (128)
Requested Service Bit 6 (64)
Indicates that the SRQ line of the IEEE-488 interface has been asserted by the
RPM4. This bit is cleared when a serial poll is performed on the RPM4, 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.
Master Summary Status Bit 6 (64)
Indicates that an event or events occurred that caused the RPM4 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.
Event Summary Bit 5 (32)
Indicates if an enabled bit in the Standard Event Status Register became set(see Section 4.5.3).
Message Available Bit 4 (16)
Indicates that at least one reply message is waiting in the RPM4 IEEE-488 output
queue.
Error Queue Not Empty Bit 2 (4)Indicates that at least one command error message is waiting in the RPM4 IEEE488 error message queue. Use the “ERR?” query to get this message.
Ready Summary Bit 0 (1)Indicates that an enabled bit in the Ready Status Register became set.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

4.5.3

STANDARD EVENT REGISTERThe RPM4 contains an 8 bit Standard event register that reflects specific RPM4 events.
Enabled events in this register will set or clear the ESB bit of the Status Byte Register.
Table 19. 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 (128)
Indicates that the RPM4 power has been cycled since the last time this bit wasread or cleared.

URQ

User Request Bit 6 (64)
Indicates that the RPM4 was set to local operation manually from the front panelby the user (pressing the [ESC] key).

CMD

Command Error Bit 5 (32)
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 (16)
Indicates if a remote program message cannot be processed due to device
related condition.

DDE

Device Dependent Error Bit 3 (8)Indicates that an internal error has occurred in the RPM4 such as a transducer timeout.

QYE

Query Error Bit 2 (4)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 RPM4 without reading a waiting reply.

RQC

Request Control Bit 1 (2)This bit is not supported as the RPM4 cannot become the active controller in charge.

OPC

Operation Complete Bit 0 (1)Indicates that the RPM4 has completed all requested functions.

4.5.4

READY STATUS REGISTERThe RPM4 contains an 8 bit Ready Status Register that reflects specific RPM4 Q-RPT
measurement ready events. Enabled events in this register will set or clear the RSB bit of
the Status Byte Register.
Table 20. 8 Bit Ready Status Register
N/A
(128)

MEAS
LO

NRDY
LO

RDY
LO

(64)

(32)

(16)

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N/A
(8)

MEAS
HI

NRDY
HI

RDY
HI

(4)

(2)

(1)

4. REMOTE OPERATIONThis 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.
The 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 LO Lo-RPT measurement ready Bit 6 (64)
Indicates that the Hi Q-RPT has completed a Q-RPT measurement.
NRDY LO Lo Q-RPT pressure Not Ready Bit 5 (32)
Indicates that the Hi Q-RPT made a transition from Ready to Not Ready as
defined by the stability settings (see Section 3.2.1).
RDY LOLo Q-RPT pressure Ready Bit 4 (16)
Indicates that the Hi Q-RPT is Ready as defined by the stability settings (seeSection 3.2.1).

MEAS HIHi Q-RPT measurement ready Bit 2 (4)Indicates that the Hi Q-RPT has completed a Q-RPT measurement.

NRDY HIHi Q-RPT pressure Not Ready Bit 1 (2)Indicates that the Hi Q-RPT made a transition from Ready to Not Ready as
defined by the stability settings (see Section 3.2.1).

RDY HIHi Q-RPT pressure Ready Bit 0 (1)Indicates that the Hi Q-RPT is Ready as defined by the stability settings (seeSection 3.2.1).

4.6IEEE STD. 488.2 COMMON AND STATUS PROGRAMMESSAGESThe RPM4 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 21. 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 RPM4 version, range, and serial number.

∗OPC

Set the operation complete bit when all operations have completed.

∗OPT

Read the list of installed RPM4 options.

∗RST

Reset the RPM4 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.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

4.6.1
∗CLS
PurposeCommandRemarks

Example∗ESE
PurposeCommandQuery
Default
Arguments
Remarks
Example(enhanced)
Errors∗ESR
PurposeCommandRemarks
Example(enhanced)∗IDN
PurposeQuery
Remarks
Example(enhanced)∗OPC
PurposeCommandQuery
Remarks
Example(enhanced)∗OPT
PurposeQuery
Remarks

Example(enhanced)∗RST
PurposeCommandRemarks
Example(enhanced)
See Also

PROGRAM MESSAGE DESCRIPTIONS
Clear all of the status & event structures.
“∗CLS”
This program message clears the following events and status registers:
Standard Byte Register (STB)
Standard Event Status Register (ESR)
Error Queue
Pending OPC operations
Sent:“∗CLS”
Reply:
none
Read or set the Standard Event Status Enable Register.
“∗ESE n”“∗ESE?”“∗ESE 0”n:
’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.
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.
Sent:“∗ESE=128”(enables the PON bit)
Query reply:“128” (no reply if IEEE-488)
ERR# 6:n is not valid.
Read the Standard Event Register.
“∗ESR?”The Standard Event Register contents are cleared after reading. The reply is in decimal
numeric form.
Sent:“∗ESR?”
Reply:“20” (the QYE and EXE bits are set)
Identify the RPM4 version, range, and serial number.
“∗IDN?”The identification reply is made up of the manufacture, the model, the serial number and thesoftware version. Each is separated by a comma.
Sent:“∗IDN?”
Reply:“DH INSTRUMENTS INC, RPM4 A0100/A0015, 1234, Ver2.00 -dhf”
Sets the operation complete bit when all operations have completed.
“∗OPC”“∗OPC?”
This Command enables the RPM4 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.
Sent:“∗OPC”
Query reply:“1”
Reads the list of installed RPM4 options.
“∗OPT?”
This Query returns any registered option(s) installed in the RPM4. Each option is separated
by a comma. Possible options:“IEEE-488:0”
The IEEE-488 option is installed,
Sent:
Reply:“∗OPT?”“IEEE-488:0”

Resets the RPM4 settings to factory settings.
“∗RST””
This Command sets the RPM4 settings to factory settings. This equivalent to a front panel
executed RESET/SET. This does not affect the communications settings.
Sent:“∗RST”
Reply:“∗RST” (no reply if IEEE-488)
Section 3.5.4.1, Reset – Sets

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4. REMOTE OPERATION∗SRE
PurposeCommandQuery
Default
Arguments
Remarks
Example(enhanced)
Errors∗STB
PurposeCommandRemarks
Example(enhanced)∗TST
PurposeQuery
Remarks

Read or set the Service Request Enable Register.
“∗SRE n”“∗SRE?”“∗SRE 0”n:
’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.
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.
Sent:“∗SRE=48” (enables the MAV and ESB bits)
Query reply:“48” (no reply if IEEE-488)
ERR# 6:n is not valid.
Read the Status Byte Register.
“∗STB?”The Status Byte Register reflects the general status of the RPM4. The ‘MSS’ bit state isrepresented by bit 6.
Sent:“∗STB?”
Reply:“80” (The MSS and MAV bits are set)

Example(enhanced)

Read the power on self test status.
“∗TST?””The RPM4 system memory stores the user settings (units, resolution) 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 RPM4 passed the test on power-up OR if the ∗TST
query was used at least once since the RPM4 was powered up the reply will be a ‘0’.
Sent:“∗RST?”
Reply:“1”*RSE
PurposeCommandQuery
Default

Read or set the Ready Status Enable Register.
“RSE n”“RSE?”“RSE 0”

Arguments
Remarks
Example(enhanced)
Errors*RSR
PurposeCommandRemarks
Example(enhanced)’0 to 255’ This is the decimal representation of the bit(s) to enable. To enable
the RDY bit, the argument would be 1.
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.
Sent:“∗RSE=1” (enables the RDY bit)
Query reply:“1” (no reply if IEEE-488)
ERR# 6:n is not valid.
n:Read the Ready Status Register.
“RSR?”The Ready Status Register contents are cleared after reading.
numeric form.
Sent:“RSR?”
Reply:“6” (The MEAS and NRDY)

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5. MAINTENANCE, ADJUSTMENTS AND CALIBRATIONS

5.

MAINTENANCE,ADJUSTMENTS A N D C A L I B R A T I O N

5.1

OVERVIEW

RPM4 was designed for maintenance free operation. No maintenance is required other than:•

Regular AutoZeroing of quartz reference pressure transducer(s) (Q-RPT) (see Section 3.5.1).

•

Periodic calibration of Q-RPT(s) (see Section 5.2).

•

Adjustment of the on-board barometer, if present (see Sections 5.3).

This section provides information on maintenance, adjustment and calibration procedures, and recommended
overhaul procedures.
RPM4 is a sophisticated pressure measuring instrument with advanced on-board features andfunctions. Before assuming that unexpected behavior is caused by a system defect or breakdown, use
this manual and other training facilities to become thoroughly familiar with RPM4 operation.
For rapid assistance in specific situations see Chapter 6 for troubleshooting information.

RPM4 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. For warranty service, contact a DHI Authorized Service Provide (seeTable 29).

5.2

CALIBRATION OF QUARTZ REFERENCE PRESSURE
TRANSDUCERS (Q-RPTS)
5.2.1

PRINCIPLE

RPM4 is equipped with one or two quartz reference pressure transducers (Q-RPTs)
used for low uncertainty pressure measurement.
To calibrate a Q-RPT, pressures from a reference standard are applied to the Q-RPT at
ascending and descending pressure increments over the range. The recommended
pressure sequence for a calibration varies depending on whether the Q-RPT is of Standard orPremium class (see Section 1.2.2.1). The pressure defined by the standard and thecorresponding Q-RPT readings are recorded at each point. After all of the pressures havebeen applied and recorded, adjustments are made to fit the Q-RPT pressure readings to thestandard. 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 standard. The Q-RPT output isadjusted by user settable coefficients: PA (an adder or offset) and PM (a multiplier or spanset) (see Section 5.2.1.1).

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RPM4™ OPERATION AND MAINTENANCE MANUALThe calibration process is performed independently on each Q-RPT to arrive at its optimal fit.
CalTool for RPTs software provided with the RPM4 supports the calibration process of
RPM4 Q-RPTs. CalTool and its documentation are provided on a General Accessories Disk with a
new RPM4 and can be downloaded from www.dhinstruments.com. Most users should use
CalTool software to assist in the calibration of RPM4.
RPM4 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). RPM4 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 5.2.8).

5.2.1.1

PA AND PM COEFFICIENTSThe 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 from the front panel in the CAL
function (see Section 5.2.7). PA and PM values are automatically edited when
CalTool software results are activated.
As editing PA and PM values will change Q-RPT calibration, they should only
be edited by qualified personnel as part of the calibration process. Caution
should be taken to avoid accidental editing and a security system isavailable to prevent access (see Section 3.5.5.5). Incorrect editing of PA
and PM values can cause out of tolerance measurements.

A new RPM4 is delivered with PA and PM values set to zero and 1 for all
ranges. This does not mean that the RPM4 has not been calibrated. In theoriginal factory calibration, privileged factory coefficients are used forcalibration with the user PA and PM set to zero and 1.

5.2.1.2

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 RPM4 Q-RPTs can be obtained in several ways.
When the RPM4 CalTool calibration assistance software is used, as received
data is displayed while running the calibration and is automatically recorded andreported if desired. As left data is also calculated and presented.
At any time, a) reference pressures applied; b) associated Q-RPT 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 the Q-RPT© 2004-2007 DH Instruments, a Fluke Company

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5. MAINTENANCE, ADJUSTMENTS AND CALIBRATIONS

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 readingsthat the transducer would have made with the old PA, PM and Poffset).
It is recommended that “as received” values of PA, PM and Poffset (for Axxx
Q-RPTs if absolute mode AutoZero is used in normal operation) be recorded foreach Q-RPT prior to running the calibration. The current PA, PM and Poffset (for
Axxx Q-RPTs) can be viewed by pressing [SPECIAL], <8cal>, <1view>.

5.2.2

EQUIPMENT REQUIREDThe recommended calibration standards for RPM4 Q-RPTs are DHI PG7000 pistongauges (PG7102, PG7202, PG7601 for gas; PG7302 for oil). Contact DHI for additional
information.

5.2.2.1

GAS OPERATED Q-RPTS, A10M AND LOWER

Gas operated piston gauge (deadweight tester), with the following
characteristics:•

Measurement uncertainty of ± 0.0025 % of reading for Standard Class
Q-RPTs or ± 0.002 % of reading for Premium Class Q-RPTs. A standard
with higher measurement uncertainty may be used but RPM4 measurement
uncertainty may be degraded proportionally from published specifications.

•

If the Q-RPT is Axxx (absolute) and will be used in the absolute and/or
negative gauge measurement modes, the reference must be able to apply
absolute pressures: Absolute pressures may be defined either by operation
relative to an evacuated bell jar or, for higher pressures, by addition of
atmospheric pressure measured by a suitable barometer. Axxx (absolute)
Q-RPTs that will not be used in absolute or negative gaugemeasurement modes (as is often the case for higher pressure Q-RPTs)
do not require the application of absolute pressure for calibration andmay be calibrated using a gauge pressure standard.
Axxx (absolute) Q-RPTs calibrated in gauge measurement mode by
applying gauge reference pressure values should be used in gauge mode
only (see Sections 3.3.3,  PRINCIPLE, 5.2.5).

•

Able to supply the recommended sequence of pressure points in therange to be calibrated:
See Section 5.2.4 for information on therecommended calibration point sequence for various Q-RPT types
and classes.

5.2.2.2

OIL OR GAS OPERATED Q-RPTS A14M AND HIGHER

Gas or oil operated piston gauge (deadweight tester), with the following
characteristics:
Do not put oil or other liquids in a Q-RPT that is meant to be operated
with gas.

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RPM4™ OPERATION AND MAINTENANCE MANUAL•

Measurement uncertainty of ± 0.008 % of reading for Standard Class
Q-RPTs or ± 0.005 % of reading for Premium Class Q-RPTs. A standard
with higher measurement uncertainty may be used but RPM4 measurement
uncertainty may be degraded proportionally from published specifications.

•

If the Q-RPT is Axxx (absolute) and will be used in the absolute and/or
negative gauge measurement modes, the reference must be able to apply
absolute pressures: Absolute pressures may be defined by adding
atmospheric pressure measured by a barometer to gauge pressure defined by apiston gauge. Axxx (absolute) Q-RPTs that will not be used in absolute or
negative gauge measurement modes (as is very often the case for higher
pressure Q-RPTs) do not require the application of absolute pressure
for calibration and may be calibrated using a gauge pressure standard.
Axxx (absolute) Q-RPTs calibrated in gauge measurement mode by
applying gauge reference pressure values should be used in gauge mode
only (see Sections 3.3.3,  PRINCIPLE, 5.2.5).

•

5.2.3

Able to supply the recommended sequence of pressure points in therange to be calibrated:
See Section 5.2.4 for information on therecommended calibration point sequence for various Q-RPT types andclasses.

SET-UP AND PREPARATIONTo set-up and prepare an RPM4 for calibration of a Q-RPT:
Set the RPM4 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 the calibration standard output to the TEST(+) port of the Q-RPT module to becalibrated on the RPM4 rear panel (1/8 in. NPT F or DH500F depending on range, see
Section 2.3.5).
If the Q-RPT module has a TEST(-) port, leave it unobstructed or connect it to thereference standard’s TEST(-) port if available.
Open SDS (Self Defense System) if present (see Section 3.3.8) for the Q-RPT to becalibrated. When the RPM4 indicates <SDS CLOSED>, the TEST(+) port is isolated fromthe Q-RPT to be calibrated.
Opening SDS with a pressure greater than Pmax! applied to the test port may cause
overpressure damage to the Q-RPT.

The Q-RPTs of RPM4s used in parallel measurement mode must be adjusted separately.
PA and PM for the Hi and Lo Q-RPT need to be determined and set individually. Therefore,
data to be used in determining calibration coefficients cannot be taken in parallel mode(see Section 3.5.7.3). Do not run a calibration with the HL (parallel mode) Q-RPT active.

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5.2.4

RECOMMENDED CALIBRATION POINT SEQUENCE

Calibration adjustments to RPM4 Q-RPTs are made by altering calibration coefficients,
PA and PM (see Section 5.2.1.1). 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 Standard or Premium Class (see Section 1.2.2.1). The class of theRPM4 Q-RPTs is indicated in the model number on the product label and on the rear panel
Q-RPT label (
 for standard, <p> for premium, for example A7Ms or A7Mp).
Prior to running the calibration point sequence, the Q-RPT should be exercised by:a) Setting full scale pressure.
b) 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 5.2.4.1 gives calibration point sequences for Standard Class Q-RPTs and Section 5.2.4.2
gives calibration point sequences for Premium Q-RPTs.
It is not required that the calibration pressure standard apply precisely the nominalpressure value of each calibration point as long as the exact value of the applied pressure
is known. Best results are obtained if the actual applied pressure is within 2 % of therecommended nominal point.

5.2.4.1

STANDARD CLASS Q-RPTS

See additional information in Section 5.2.4 concerning exercising the Q-RPT anddwell time at pressure points.
Table 22. 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, or atmospheric pressure for ranges> A1.4M. Zero (vented) in gauge mode.

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 should be used in gauge mode only (see Sections 3.3.3,
 PRINCIPLE, 5.2.5).
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RPM4™ OPERATION AND MAINTENANCE MANUAL

Table 23. 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.

BGxxx (bi-directional gauge) Q-RPTs that will NOT be usedin negative gauge measurement mode may be calibrated ingauge (positive pressures) measurement mode only. Use theStandard Class gauge mode (Gxxx) calibration point
sequence (see Table 22). BGxxx Q-RPTs calibrated in gaugemeasurement mode only should not be used in negative
gauge mode.

Table 24. Calibration Point Sequence, Standard Class,
BA100K Q-RPTCALIBRATIONSEGMENT

Ascending

Descending

1.

5.2.4.2

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 BA100K span is 70 to 110 kPa absolute.

PREMIUM CLASS Q-RPTS

See additional information in Section 5.2.4 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
to include the higher density of points that is recommended for determination of thecalibration coefficients. A 5 points up, 2 points down (50%, low point) run isadequate. To verify that the uncertainty turndown with AutoRange (see Sections
3.3.4, 1.2.2.1) is in tolerance, it is recommended that the verification of a Premium
Q-RPT include verification of an AutoRanged span of 30 % of the maximum
Q-RPT span. For example, verify an A7M Q-RPT in the default range of 0 to 7 MPa(1 000 psi) and in the AutoRange range of 2.1 MPa (300 psi).

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Table 25. 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.

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 should be used in gauge mode only (see Section 5.2.5).
Table 26. 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.

BGxxx (bi-directional gauge) Q-RPTs that will not be used innegative gauge measurement mode may be calibrated ingauge (positive pressures) measurement mode only. Use thePremium Class gauge mode (Gxxx) calibration point sequence(see Table 25).
BGxxx Q-RPTs calibrated in gaugemeasurement mode only should not be used in negative
gauge mode.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

5.2.5

TURNING OFF ABSOLUTE AND NEGATIVE GAUGEMEASUREMENT MODES FOR AXXX (ABSOLUTE) Q-RPTS

 PURPOSE
To prevent operation in absolute and negative gauge measurement modes on an Axxx
(absolute) Q-RPT that has been calibrated for gauge mode only.
 PRINCIPLE
Axxx (absolute) Q-RPTs are frequently used in gauge measurement mode only (see Section
3.3.3,  PRINCIPLE). Axxx Q-RPTs that are used in gauge mode only, may be calibrated ingauge mode with a reference that applies gauge pressures. Calibration with an absolutereference is not necessary. However, if an Axxx Q-RPT is calibrated in gauge mode, it is notpossible to know if it is in or out of tolerance in absolute and negative gauge modes. To avoid
using absolute and negative gauge measurement modes with an Axxx Q-RPT that iscalibrated for gauge mode only, access to absolute and negative gauge modes can be turned
OFF. This is accomplished in the [SPECIAL], <8cal> menu.
 OPERATION
See Section 5.2.7 for more detailed information on editing and viewing Q-RPT calibration
information.
Turning absolute and negative gauge mode operation ON and OFF for a Q-RPT occurs in thesame area in which calibration coefficients are edited. To access the Q-RPT calibration editing areapress [SPECIAL], <8cal> and select the desired Q-RPT. Then select <1edit> to make changes.
[ENT] through the calibration information screens.
After viewing the values of PA and PM the display is:.

Allow abs andHIneg g mode? 1yes 2no

The cursor is on the number corresponding to the current selection. Make the desired selection.
<1no> causes absolute and negative gauge modes to be unavailable for the Q-RPT.

5.2.6

Q-RPT CALIBRATION USING CALTOOL FOR RPTS
SOFTWARE
To calibrate RPM4 Q-RPTs using CalTool software, refer to Sections 5.2.1,
 PRINCIPLE, 5.2.2, and 5.2.3 in this manual and then refer to the CalTool for
RPTs Software Manual.
CalTool for RPTs software and manual are supplied on the RPM4
General Accessories Disk and can be downloaded from www.dhinstruments.com.

5.2.7

EDITING AND VIEWING Q-RPT CALIBRATIONINFORMATION 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 3.5.1
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 Sections 5.2.1.1).

•

The value of PM – The pressure multiplier for the selected Q-RPT (see Sections 5.2.1.1).

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Absolute and negative gauge measurement modes ON or OFF (Axxx Q-RPTs only)– See Section 3.3.3,  PRINCIPLE for complete information on measurement modes.
This is set to OFF if an Axxx Q-RPT was calibrated in gauge mode with a gaugepressure standard.

 OPERATIONAs 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 the calibration process. Caution
should be taken to avoid accidental editing. A user level security system is available tocontrol access (see Section 3.5.5.5).

A new RPM4 is delivered with PA and PM values set to zero and 1 for all ranges. This does
not mean that the RPM4 has not been calibrated. In the original factory calibration, privileged
factory coefficients are used for calibration with the user PA and PM set to zero and 1.
To access Q-RPT calibration information viewing or editing press [SPECIAL], <8Cal>.
Select the desired Q-RPT. The <1view> selection displays the calibration information fields.
The <2edit> function 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:20030325 Hi
AbsPoffset: 0.0 Pa

If in edit mode, the calibration information fields can be edited. Edits to Poffset are common
with changes made in the AutoZ edit or run function (see Section 3.5.1). Pressing [ENT] on
the last field goes 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 Pa
PM: 1.000000

Hi

If in edit mode, the calibration fields can be edited. If the selected Q-RPT is an Axxx Q-RPT,pressing [ENT] in the PM field goes to the next calibration information display (this display isskipped if the Q-RPT is a Gxxx or BGxxx type):

1.

Position designator of the Q-RPT being viewed.

2.

Cursor is on current ON or OFF selection.

Absolute andHi
neg g mode: 1on 2off

The cursor is on the current setting. If in edit mode, the ON or OFF status can be changed
by selecting <1on> or <2off> (see Section 5.2.5). [ENT] in view mode returns to theview/edit screen. [ENT] in edit mode goes to confirmation of change activation if changes have

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RPM4™ OPERATION AND MAINTENANCE MANUAL

been made in any of the calibration screens. Pressing [ESC] in any edit screen exits the edit screen
without activating any changes.
The value of PA is always in Pascal (Pa). The value of PM is dimensionless.

5.2.8

Q-RPT CALIBRATION/ADJUSTMENT WITHOUT CALTOOLFOR RPTS SOFTWARE PRINCIPLEThe RPM4 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 RPM4.

•

Calculating new PA and PM values and entering them.

•

Setting Poffset to zero for Axxx Q-RPTs.
Before proceeding to calibrate a reference pressure transducer without using CalTool for RPTs
software, Sections 5.2, Calibration of Reference Pressure Transducers, 5.2.1  PRINCIPLE,
5.2.2 Equipment Required, 5.2.3 Setup and Preparation should be reviewed thoroughly.

The Q-RPTs of RPM4s used in parallel measurement mode must be adjusted separately.
PA and PM for the Hi and Lo Q-RPT need to be determined and set individually. Therefore,
data to be used in determining calibration coefficients cannot be taken in parallel mode(see Section 3.5.7.3).
 OPERATION
The typical procedure for calibrating a Q-RPT is:
Set-up and prepare the RPM4 for calibration (see Sections 5.2.2, 5.2.3).
Use the [RANGE] function key to select the Q-RPT to be calibrated (see Section 3.3.1).
Be sure to set the DF range (not an AutoRanged range).
Use [HEAD] to set the HEAD to zero (see Section 3.3.7). Use [UNIT] to set the desiredpressure unit of measure (see Section 3.3.2). Use [MODE] to set the desired pressure
measurement mode (see Section 3.3.3). Axxx (absolute) Q-RPTs that will be used ingauge measurement mode only, may be calibrated in gauge measurement mode with agauge pressure standard (see Section 5.2.5).
Use [SPECIAL], <1AutoZ> to access the AutoZ function (see Section 3.5.1).
If calibrating in absolute measurement mode, turn AutoZ ON if it is left ON in normal
RPM4 operation.
If calibrating in gauge measurement mode, always turn AutoZ ON.
Use [SPECIAL], <8cal>, <1Hi RPT> or <2Lo RPT>, <1view>, to 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.

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Run the recommended calibration point sequence for the Q-RPT (see Section 5.2.4).
Record the pressure applied by the standard and the RPM4 reading at each calibration
point. Dwell at least 60 seconds at each point after setting the reference pressure toallow full stabilization The data recorded is the “as received” data for this calibration.
Enter the calibration pressures and RPM4 readings into a spreadsheet. Calculate the“non-corrected” RPM4 readings by backing out the PA, PM and Poffset (Poffset in the case of
Axxx (absolute) Q-RPTs in absolute mode only, do not back out Poffset for for gauge mode
calibrations) recorded in Steps and above, following:
non-corrected reading = ((corrected reading - PA)/PM ) + Poffset
Perform a linear regression to find the offset and slope that best fit the non-corrected
RPM4 readings to the calibration standard pressures. The offset is the new value of PA,
the slope is the new value of PM.
Press [SPECIAL], <8Cal>, <1Hi RPT> or <2Lo RPT>, <2edit> and write the new
calibration date and the new values of PA and PM for the Q-RPT calibrated (see Section
5.2.7). 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 the calibration.
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.

5.3

ADJUSTMENT OF ON-BOARD BAROMETER PURPOSE
To adjust the output of the on-board barometer (see Section 1.2.2.2).
RPM4’s that have only G100K or G200K Q-RPTs (no Axxx or G15K or BGxxx) 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 5.2.1.1).
The on-board barometer is a low accuracy sensor used only for measuring changes in atmosphericpressure over short periods of time (see Section 3.2.2) and the line pressure for G15KK and BG15K
line pressure compensation. RPM4 measurement uncertainty does not depend on the measurement
uncertainty of the on-board barometer.
 OPERATION
To edit the values of PA and PM for the barometer, press [SPECIAL], <8cal>, <3barometer>. Pressing[ENT] steps through displays of the calibration date (YYYYMMDD) and PA and PM. In edit mode, thevalues can be edited. Pressing [ENT] after the last screen activates the edited values.
To view the current output of the on-board barometer, press [SPECIAL], <7Internal>, <3baro>.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

5.4

RELOADING EMBEDDED SOFTWARE INTO FLASHMEMORYRPM4 uses FLASH memory. This allows the embedded software that controls RPM4 operations andfunctions to be loaded into RPM4 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 SOFTWARE. A FLASH loading utility and the latest RPM4
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(see Table 29) for assistance.
If you believe you have discovered an error or “bug” in RPM4 software, please report it with complete
details by email to cal.repair@dhinstruments.com or submit an on-line Quality Feedback Reportunder CALIBRATION & REPAIR at www.dhinstruments.com.
The DHI flash software loading utility and RPM4 embedded software are available for download fromwww.dhinstruments.com in the SOFTWARE section.

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5. MAINTENANCE, ADJUSTMENTS AND CALIBRATIONS

5.5

SUBASSEMBLY DESCRIPTION AND LOCATION

1. Micro Card
2. Power Supply Module(beneath Driver Board)

3. Driver Board
4. On-Board Barometer (if present)
5. Lo Q-RPT module (if present)(< A7M style shown)

6. Hi Q-RPT module(< A7M style shown)
7. Display

Figure 7. Internal View

5.5.1

MINI MICRO BOARD

The micro board supports a Motorola 68302 micro-controller, EPROM, EEPROM, 128k x 16
bit NVRAM, 8 Mbit flash memory; RS-232 and IEEE-488.2 communications; keypad anddisplay control. An I/O port controls other ports and devices in RPM4.

5.5.2

POWER SUPPLY MODULE+ 12 V DC (± 2 %) @ 2.1 Amps

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5.5.3

DRIVER BOARD

The driver board is controlled by the mini micro board (see Section 5.5.1). It supports:
•
•
•
•
•
•
•
•

12 V drivers for internal solenoid valve actuation
Frequency counters (2) for reading Q-RPTs (see Section 5.5.5)
On-board barometer power and output (see Section 5.5.4)
Utility sensor (if present) power and output
Power to the system cooling fan
Remote [ENT]
Keypad and display
Beeper

5.5.4

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 quartz reference pressure transducer (see Section 3.2.2). The temperature sensor
is used for temperature compensation of the barometric sensor.
RPM4s that have only G100K or G200K Q-RPTs (no Axxx or G15K or BGxxx) are NOT
equipped with an on-board barometer.

5.5.5

Q-RPT MODULE

The Q-RPT module is an integrated Quartz Reference Pressure Transducer (Q-RPT)
assembly. The module includes a Q-RPT, brackets to hold the transducer, interconnecting
tubing, a manifold with TEST(+),TEST(-) (A70M and lower only) and VENT (ATM on A100M
and higher) ports and SDS (Self Defense System) solenoid valves (A7M and lower, gas
operated, only).
A Q-RPT provides very high precision, low uncertainty pressure measurement. The basic
sensing principle is the measurement of the change in the natural oscillating frequency of aquartz tuning fork in response to changes in temperature and mechanical stress resulting
from the change in pressure 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.
See Figure 8 for pneumatic schematics of different Q-RPT module configurations.

5.5.5.1

HI Q-RPT MODULE

RPM4 is always equipped with a Hi Q-RPT module. The Hi Q-RPT module is in
the Hi Q-RPT position. It is always the higher range in two Q-RPT RPM4s.

5.5.5.2

LO Q-RPT MODULE

RPM4 may be equipped with a Lo Q-RPT module. The Lo Q-RPT provides alower measurement range than the Hi Q-RPT. See Section 1.2.2.1 for complete
Q-RPT specifications.

5.5.6

DISPLAY2 x 20 character vacuum fluorescent display.

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5.6

Q-RPT MODULE PNEUMATIC SCHEMATICS

Axxx Q-RPT >A10M(No SDS)

Axxx Q-RPT <A10M
VALVE
STATE

CONDITIONAB

SDS OpenOC

SDS Closed

C

O

Power offCO

Gxxx or BGxxx Q-RPT
VALVE
STATE

CONDITIONABCSDS OpenOCC

SDS Closed

C

O

O

Power offCOO

Figure 8. Pneumatic/hydraulic schematics of RPM4 with Single Q-RPT Module

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RPM4™ OPERATION AND MAINTENANCE MANUAL

The pneumatic schematic for RPM4’s with two Q-RPT modules is the same as for the single Q-RPT
modules in Figure 8 with the following exceptions:•If both modules use the barometer, the barometer is connected to teed to both module barometer
connection points.

•

An exception is the combination of an Axxx with SDS (<A10M) and a G15K or BGxxx shown below.

Axxx Q-RPT <A10M with G15K or
BGxxx

Figure 9. Pneumatic/hydraulic schematics of RPM4 with Two Q-RPT Modules© 2004-2007 DH Instruments, a Fluke Company

Page 130

6. TROUBLESHOOTING

6.

TROUBLESHOOTING

RPM4 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
RPM4 operation. This troubleshooting guide is intended as an aid in identifying the reason for RPM4
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 27. Troubleshooting GuideSYMPTOMPROBABLE CAUSESOLUTION

Will not power up.

Blown fuse.

Replace fuse.

Cannot access certain functions>ACCESS RESTRICTED<

User level has been set that restrict accessto certain functions.

Change user level or consult systemmanager. 3.5.5.5

Displays <FATAL ERROR> or<FATAL FAULT>.

Encountered unresolved internal software
conflict.

Cycle power to clear. Please record
conditions leading up to event including
the numbers displayed when [ENT] ispressed and report to your DHI
Authorized Service Provider. Table 29

Front panel keys seem to bedisabled.

<remote> command has been sent from ahost computer.

Send <local> command from hostcomputer or cycle RPM4 power. 4, 4.4.4

Measured pressure display orother displays have too much/not
enough resolution.

Resolution setting needs to be changed.

Change resolution setting. 3.4.2

Can’t increase resolution to level
desired in AutoRanged range.

Resolution setting is limited when
AutoRanging under 10 % of Q-RPT default
range.

Operation is normal. Table 6

Values that should be non-zero
are displayed as zero.

Resolution setting needs to be increased toview significant digits.

Change resolution setting. 3.4.2

Keypad presses make undesired
sounds or NO sounds.

Keypad sound settings are incorrect.

Use keypad function to set keypadsounds as desired. 3.5.5.2

Bottom line of display haschanged and you want to change
it back.

The DISPLAY function has been used tochange the display.

Use [DISPLAY] to set bottom line todesired display. 3.3.6

Second line of display is<PPC3 EXT DEV:>
and front keypad is locked out.

The RPM4 has been initialized as anexternal device to a PPC3 pressure
controller and is still in external device mode.

Cycle RPM4 power to take it out of
external device mode and restore local
operation. 3.2.5

Bottom line of display is blank.

DISPLAY mode is “clean”.

Operation is normal. Use [DISPLAY] tochange bottom line display if desired.
3.3.6

The pressure units available
under the [UNIT] function key are
not the ones you want.

UNIT function needs to be customized.

Use PresU function to customize the
UNIT function or reset units to default.
3.5.6

Front panel display is dim.

Screen saver option has activated.

Operation is normal. Press any key toresume full screen power. Adjust screen
saver time, if desired. 3.5.5.1

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RPM4™ OPERATION AND MAINTENANCE MANUALSYMPTOMPROBABLE CAUSESOLUTION

The Q-RPT range does not cover the desired
AutoRange.

Check that Q-RPT default range is highenough to cover the AutoRange. Table 1

The specified operating mode is absolute or
negative gauge and absolute and negativemodes are OFF for the desired Q-RPT

Check that absolute/negative gauge is ON
for the Q-RPT. 5.2.5

The Q-RPT is Gxxx (gauge only) and thespecified operating mode is absolute or
negative gauge..

Check that the Q-RPT type supports thedesired measurement mode. 3.3.3

Range will NOT change. Displays“Pressure on Hi (or Lo) RPT
exceeds RR upper limit”.

The pressure currently applied to the rangethat is being selected exceeds the UL (upper
limit) set for that range.

Reduce pressure applied to test port toless than UL of target range. 3.4.4

Pressure display is flashing andbeeper is sounding intermittently.

Current upper limit of active range has been
exceeded.

Reduce pressure. Change UL and/or
active range if needed. 3.4.4

Pressure display is flashing andbeeper is sounding intermittently
while operating in differential
mode.

Differential pressure upper limit OR Hi QRPT upper limit is exceeded.

Reduce differential pressure and/orpressure on Hi Q-RPT to be less thanupper limit values or change upper limit
value(s). 3.4.4, 3.3.3.1

Pressure display is NOT flashingand beeper is sounding
intermittently while operating indifferential mode.

Lo Q-RPT upper limit is exceeded. If Lo QRPT is displayed on second line, its
measured pressures is flashing.

Reduce pressure on Lo Q-RPT orchange its upper limit. 3.4.4, 3.3.3.1“Hi (or Lo) RPT EXCEEDEDPMAX” displays alternating withnormal display.

RPM4 Q-RPT has been overpressured(Pmax! exceeded).

Correct the overpressure condition andcycle power ON and OFF to clear.
3.4.4.1

Rapid beeping for 8 seconds and<Check RPT connection>
displayed in second line.

RPM4 is in parallel measurement mode andthe disagreement in pressure measured by
the two Q-RPTs indicates they may not be
connected in parallel.

If parallel measurement mode is notdesired, change ranges or turn it off.
If parallel measurement is desired,check that the Hi and Lo Q-RPTs areconnected to the same pressure.
Ignore if having the two Q-RPTs on two
different pressures is intentional. 3.5.7.3

A Ready (green Ready/Not Ready
indicator) indication is neverachieved.

Stability settings is too tight and/or existing
conditions will not allow Ready to beachieved.

Adjust stability setting or correct otherconditions. 3.4.3, 3.2.1

Cannot select absolute or negative
gauge measurement mode.

Q-RPT is Gxxx and does not support
absolute and gauge measurement modes or

Operation is normal. 3.3.3

Cannot select differential
measurement mode.

RPM4 must have two Q-RPTs of the same
type (Axxx, Gxxx, BGxxx) and the current
range must be the default range (<DF>) of
the Hi Q-RPT for differential measurementmode to be available.

If RPM4 has two Q-RPTs of the same type,set the default range of the Hi Q-RPT.
3.3.3.1

Q-RPT is Axxx (absolute) but
cannot select absolute or negative
gauge measurement mode.

Absolute and negative gauge measurementmode have been turned off in the calibration
function.

Check that absolute/negative gauge is ON
for the Q-RPT. 5.2.5

Display update rate of indicatedpressure changes when changing
pressure.

RPM4 automated read rate function is ON toautomatically adjust read rate depending
upon rate of change of pressure.

Operation is normal. Turn automatedread rate function OFF if desired. 3.5.7.2

Pressure is changing but displayof pressure is NOT and thebottom right hand corner of thedisplay is a numerical countdown
followed by <avg>.

Average DISPLAY function is ON andpressure display is updating only with theaverage value at the end of each averaging
cycle.

Go to a DISPLAY function other than
average or press [+/-] to get the
instantaneous value Average DISPLAY.
3.3.6

Display update of indicatedpressure is too slow whenpressure is changing quickly.

RPM4 automated read rate function is OFF.

Turn automated read rate function ON toautomatically adjust read rate depending
on pressure rate of change. 3.5.7.2

Pressure measurement seems
erratic when measuring gas
pressure.

The RPM4 and/or the connection to the test
system is contaminated with liquids.

Purge and clean affected systems.
Contact DHI Authorized Service
Provider if RPM4 is contaminatedinternally. Table 29

Pressure indicated by RPM4
never becomes stable.

These is a leak in the pressure system towhich RPM4 is connected.

Find and correct leak. Consider using
RPM4 leak check function. 3.3.5

AutoRange is not selecting thedesired Q-RPT for the specified
range.

© 2004-2007 DH Instruments, a Fluke Company

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6. TROUBLESHOOTINGSYMPTOMPROBABLE CAUSESOLUTION

Disagreement between two Q-RPTs
in system appears excessive.

Difference is actually within tolerance andacceptable disagreement.

Compare differences observed totolerances on Q-RPT measurements.
1.2.2.1

Apparent inaccurate pressure
control/measure and little or no
response from Q-RPT:

Reference transducer destroyed byoverpressure.

Contact DHI Authorized Service Provider.
Table 29

Incorrect pressure units and/or measurementmode (gauge or absolute).

Set desired pressure units and/or
measurement mode. Consider reference
temperature if unit is inWa. 3.3.2, 3.3.3

Q-RPT calibration coefficients have beenaltered.

Check and correct calibration coefficients ifneeded. 5.2

AutoZ has been run and turned ON with anincorrect standard for zero.

Check value of Poffset. Rerun AutoZ with avalid reference. 3.5.1

An unplanned “head” correction is active orhead height or fluid is incorrect.

Operation is normal. Remove or change“head” correction. 3.3.7

Need to run AutoZ to rezero in gauge mode.

Run AutoZ. 3.3.9

Current measurement mode is absolute andRPM4 is indicating atmospheric pressure.

Check measurement mode setting andset to gauge if gauge pressure
measurements are desired. 3.3.3

Pressure applied is atmospheric
but RPM4 indicates near zero.

Current measurement mode is gauge andRPM4 is indicating zero gauge pressure.

Operation is normal. Checkmeasurement mode setting and set toabsolute if absolute pressure
measurements are desired. 3.3.3

A third Q-RPT designated HL isavailable but RPM4 has only two
Q-RPTs.

Parallel measurement mode has been
activated.

Operation is normal. Turn off parallelmeasurement mode if desired. 3.5.7.3

NOT reading pressure applied tothe test port and <SDS CLOSED>is flashing over the pressure
indication.

SDS is CLOSED for the active Q-RPT so thepressure applied to the test port is NOT
getting to the Q-RPT.

After taking precautions to assure thatpressure applied to test port is safe for
the RPT, OPEN SDS. 3.2.7, 3.3.8

RPM4 may have two TEST(+) ports and thepressure to be measured is connected to thewrong Q-RPT’s port

Familiarize yourself with your RPM4
configuration. Connect pressure to bemeasured to correct TEST(+) port.
2.3.5, 5.6

RPM4 may have two TEST(+) ports andpressure to be measured is connected tocorrect port but active Q-RPT is NOT the
Q-RPT on that TEST port.

Familiarize yourself with your RPM4
configuration. Select active range to beon the Q-RPT to which the pressure to
be measured is corrected. 5.6, 3.3.1<SDS CLOSED> is displayedalternating with the measured
pressure.

SDS is CLOSED for the active Q-RPT.

Operation is normal. OPEN SDS if
desired. 3.3.8

SDS should be present on a
Q-RPT but does not seem to be
active.

SDS has been turned full time OFF for the
Q-RPT.

Turn SDS full time ON. 3.5.4.2

SDS will not OPEN for the Q-RPT
shown on the second line in the
Q-RPT DISPLAY function.

When not in differential or parallelmeasurement mode, SDS on the inactive
Q-RPT can only be OPENED using direct
SDS control.

Use direct SDS direct control to OPEN
SDS on the inactive Q-RPT. 3.5.4.1

SDS was left OPEN on one
Q-RPT when ranges werechanged. When you come backto it, its CLOSED again.

When changing ranges causes a change ofthe active Q-RPT, SDS is always CLOSED
for the Q-RPT that becomes inactive.

Operation is normal. 3.2.7

You would like to eliminate the
SDS function for a Q-RPT.

Set SDS to be inactive except for an
overpressure situation.

Turn SDS full time OFF for the Q-RPT.
3.5.4.2

Apparent inaccurate pressure
measurement.

Apparent inaccurate pressure
measurement and <h> isdisplayed on top line of screen.
Pressure applied is zero gauge
but reading is NOT zero.

Is NOT reading pressure applied
to the TEST(+) port.

Page 133© 2004-2007 DH Instruments, a Fluke Company

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Page 134

7. APPENDIX

7.

APPENDIX

7.1

REMOTE [ENT]The RPM4 remote ENTER function operates by detecting the open or closed status of the REMOTE
ENTER switch.
The normal status of the ENTER switch is OPEN. When RPM4 detects a CLOSED condition held for 300 ms,
it is interpreted as equivalent to a press of the [ENT] key.
Any switch may be used to accomplish the remote ENTER function. The switch should be installed on
the optional remote ENTER cable (DHI P/N 103128). Install the switch by connecting its two terminals tothe black and white wires of the remote ENTER cable.

Figure 10. Remote [ENT] Connector Schematic
1. Black wire

2. White wire

Page 135© 2004-2007 DH Instruments, a Fluke Company

RPM4™ OPERATION AND MAINTENANCE MANUAL

7.2

UNIT CONVERSION
7.2.1

PRESSURE

RPM4 performs all internal calculations in SI units. Numerical values input or output in otherunits are converted to SI immediately after entry and back to other units just before output asneeded.
Table 28 provides the conversion coefficients used by RPM4 to convert numerical values
expressed in SI units to corresponding values expressed in other units.
Table 28. 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-03

barBar

1.0 E-05mmWa @ 4°C

millimeter of water

1.019716 E-01

mmHg @ 0°C

millimeter of mercury

7.50063 E-03

psi

pound per square inch

1.450377 E-04

psf

pound per square foot1.007206 E-06

inWa @ 4°C

inch of water

4.014649 E-03

inWa @ 20°C

inch of water

4.021732 E-03

inWa @ 60°F

inch of water

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 below

M

meter 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 of altitude in feet. RPM4 uses a set of equations to model thepressure/altitude relationship. The worst case deviation between the MIL-STD-859A
table and the calculated pressure is 0.0001 inches of mercury (0.3 Pa). The pressure
quantity expressed in inches of mercury is converted to Pascal following Table 28 above.
For altitude expressed in meters, meters are converted to feet using 1 m = 3.28084 ft.

© 2004-2007 DH Instruments, a Fluke Company

Page 136

8. WARRANTY8.

WARRANTY

8.1

OVERVIEW

Except to the extent limited or otherwise provided herein, DH Instruments, a Fluke Company warrants
for one year from purchase, each new product sold by it or one of its authorized distributors, only against
defects in workmanship and/or materials under normal service and use. Products which have beenchanged or altered in any manner from their original design, or which are improperly or defectively
installed, serviced or used are not covered by this warranty.
DH Instruments and any of its Authorized Service Providers’ obligations with respect to this warranty are
limited to the repair or replacement of defective products after their inspection and verification of such
defects. All products to be considered for repair or replacement are to be returned to DH Instruments or
its Authorized Service Provider after receiving authorization from DH Instruments or its Authorized
Service Provider. The purchaser assumes all liability vis a vis third parties in respect of its acts oromissions involving use of the products. In no event shall DH Instruments be liable to purchaser for any
unforeseeable or indirect damage, it being expressly stated that, for the purpose of this warranty, suchindirect damage includes, but is not limited to, loss of production, profits, revenue, or goodwill,
even if DH Instruments has been advised of the possibility thereof, and regardless of whether suchproducts are used individually or as components in other products.
The provisions of this warranty and limitation may not be modified in any respect except in writing signed
by a duly authorized officer of DH Instruments.
The above warranty and the obligations and liability of DH Instruments, a Fluke Company and its
Authorized Service Providers exclude any other warranties or liabilities of any kind.
Table 29. 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

Tel 81/29.840.9111
Fax 81/29.840.9100
tech@ohtegiken.co.jp

Japan/Asia

DH 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 137© 2004-2007 DH Instruments, a Fluke Company

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Page 138

9. GLOSSARY9.

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).

Active Q-RPTThe Q-RPT that is currently selected to be displayed on the top line of the RPM4
display. Most function selections affect the active Q-RPT.

AutoRange

A function that optimizes RPM4 measurement and control for a specific, user defined
range of operation.

AutoRanged Range

An RPM4 pressure measurement range created using the AutoRange function.

AutoTest or ATest

RPM4 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

RPM4’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 andnegative gauge measurement modes.

Default Range (DF)A Q-RPT’s maximum range that is always available using [RANGE] and cannot be deleted.

Deviation

A DISPLAY function in which the deviation of the current pressure from a target pressure
is displayed.

DUT

Device Under Test. The device or devices pneumatically connected to the RPM4TEST(+) port that the RPM4 is being used to test or calibrate.

Differential mode

Measurement mode in which the measured pressure is the different between the Hi and
Lo Q-RPT (Hi – Lo).

FS

Abbreviation of “full scale”. The full scale value is the maximum pressure of a measurement
range. Limits and specifications are often expressed as % FS. Also see span.

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 RPM4 reference level and the DUT.

HiLo

A DISPLAY function in which the highest and lowest pressure measurements since
reset are recorded and displayed.

Hi Q-RPTThe designation of a single Q-RPT in an RPM4, or, if there are two, the one that has thehighest full scale default range.

HL Q-RPTThe designation of the pseudo Q-RPT that results from the combination of using two
Q-RPTs simultaneously in parallel measurement mode.

Inactive Q-RPTIn an RPM4 with two Q-RPTs, the Q-RPT that is not currently displayed on the top lineof the display. The inactive Q-RPT may be displayed on the second line of the RPM4
display using the RPT DISPLAY function.

Lo Q-RPTThe designation of a the Q-RPT with the lower full scale default range in RPM4s with
two Q-RPTs.

Measurement Mode

Whether pressure is being measured relative to absolute zero or vacuum (absolute mode)or relative to atmospheric pressure (gauge mode).

Negative gauge orcompound 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
is run. Used by the AutoZ function when Auto Z is ON to compensate Q-RPT readings
for changes 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 or barometer to calibrate it.

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RPM4™ OPERATION AND MAINTENANCE MANUAL

PM

Pressure multiplier, used to adjust span of a Q-RPT or barometer to calibrate it.

Parallel Measurement
Mode

Operating mode of RPM4s with two Q-RPTs in which both Q-RPTs are used to measure
together in parallel and the indicated pressure is the average of their readings. This
creates a pseudo Q-RPT designated HL.

Pmax!

The maximum pressure limit of a Q-RPT. If the pressure measured by the Q-RPT
exceeds Pmax!, an overpressure condition occurs.

PPC3

Pressure controller calibrator manufactured by DHI. RPM4 can be used as an externalreference device for a PPC3. PPC3 automates RPM4 pressure control.

Q-RPT(Quartz Reference
Pressure Transducer)

The transducer used by RPM4 for low uncertainty pressure measurement. May bedesignated as Hi, Lo or HL depending on its position and role in t he RPM4.
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

A DISPLAY function in which the rate of change of pressure in pressure unit/second isdisplayed.

Ready/Not Ready

Front panel LED indication of when the pressure measured by RPM4’s active Q-RPT isstable within the stability limit. Leading character of the second line when the inactive QRPT is displayed on the second line in RPT DISPLAY mode.

RPT2x

Parallel measurement mode in which both Q-RPTs of an RPM4 with two Q-RPTs areused together and the indicated pressure is the average of their measurements.

SDS (Self Defense
System)A system to protect Q-RPTs from overpressure made up of isolation and vent valves
and internal operating logic. Applies only to Q-RPTs designated A7M or lower.

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).

Stability Limit

A limit expressed in units of pressure per second (e.g., kPa/second). The stability limit is usedas 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.

Target

The value from which deviations are measured in the Deviation DISPLAY function.

UL (Upper Limit)

A user settable maximum pressure limit. When pressure exceeds UL, RPM4 beeps
intermittently. In negative gauge measurement mode, there is also a user settable lower limit.

User Level

Levels of security that can be set to protect certain RPM4 functions from being accessed.

QDUT

On-board automated test sequence that AutoRanges RPM4 based on characteristics of
the Device Under Test (DUT).

© 2004-2007 DH Instruments, a Fluke Company

Page 140