PC104-PDISO8
User’s Manual

Revision 3A
October, 2000

Trademark and Copyright Information
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Other product and company names mentioned herein are trademarks or trade names of their respective
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© 2000 Measurement Computing Corporation. All rights reserved. No part of this publication may be
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photocopying, recording, or otherwise without the prior written permission of Measurement Computing
Corporation.
NoticeMeasurement Computing Corporation does not authorize any Measurement Computing Corporation product for
use in life support systems and/or devices without prior written consent from Measurement Computing
Corporation. Life support devices/systems are devices or systems that, a) are intended for surgical implantation
into the body, or b) support or sustain life and whose failure to perform can be reasonably expected to result ininjury. Measurement Computing Corporation products are not designed with the components required, and are
not subject to the testing required to ensure a level of reliability suitable for the treatment and diagnosis ofpeople.

HM PC104-PDISO8.lwp

1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1 SOFTWARE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2 BASE ADDRESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.3 AC INPUT FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 REGISTER DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.2 OUTPUT REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.3 INPUT REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 ELECTRONICS AND INTERFACING . . . . . . . . . . . . . . . . . . 84.1 I/O CONNECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.1 FORM C RELAY OUTPUTS . . . . . . . . . . . . . . . . . . . . . . . . . 94.2 FORM A RELAY OUTPUTS . . . . . . . . . . . . . . . . . . . . . . . . . 94.3 ISOLATED INPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104.4 EXTENDING THE INPUT RANGE . . . . . . . . . . . . . . . . . . . 105 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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1 INTRODUCTION

1.1 DESCRIPTION
The PC104-PDISO8 has 8-channels of isolated inputs and relay outputs. The board isdesigned for sensing and control applications having high voltages.

WARNING!
High voltages will be present on the board when you haveconnected high voltage inputs or outputs to the connector.
Use extreme caution! Never handle the board when live signals areconnected to the board via the connector.
The eight outputs are electromechanical relays. Five provide FORM C connections
and three provide normally-open FORM A connection. The relays are controlled bywriting to one 8-bit port. The state of the relay control register may be read back.
The inputs are eight individual, optically-isolated inputs that may be read back as asingle byte. The inputs are not polarity sensitive and may be driven by either AC(input range −24V to +24V RMS, 50 to 1000 Hz) or DC (input range −24V to+24VDC). Each input has a switchable low-pass filter.
Although requiring only two, 8-bit ports, the board occupies four ports.

1.2 ACCESSORIESThe PC104-PDISO8 is a combination digital I/O board with signal conditioning
installed. Most accessory boards are intended to provide signal conditioning or easyto access signal termination. In general, it does not require additional signal
conditioning.

WARNING
We strongly recommend against using screw terminal boards with thePC104-PDISO8. The board is intended to sense and control high voltages. A screw
terminal board would expose yourself and others to high voltage signals.
Rather, we recommend that you construct a safe cable to carry your signals directlyfrom your equipment to the board’s connector.

12 INSTALLATION

2.1 SOFTWARE
Before you open your computer and install the board, install and run InstaCal, theinstallation, calibration and test utility included with your board. InstaCal will guide
you through switch and jumper settings for your board. Detailed information
regarding these settings can be found below. Refer to the Extended Software
Installation Manual for InstaCal installation instructions.

2.2 BASE ADDRESSThe base address switch controls the I/O location where the CPU can access theboard’s registers.
The factory default is 300 hex (768 decimal).
If you already have a board installed at address 300h, choose a new address fromthose available on your computer.
Use the list of PC I/O address
assignments found in Table 2-1 todetermine the appropriate address.
Choose a new base address fromthose available and set the switch
using the guide to the right.
If 300 hex is available on yourcomputer, there is no need tochange this switch from the factory
default setting.
Figure 2-1. Base Address Switch

2HEX
RANGE
000-00F
020-021040-043060-063060-064070-071080-08F
0A0-0A1
0A0-0AF
0C0-0DF
0F0-0FF
1F0-1FF
200-20F
210-21F
238-23B
23C-23F
270-27F
2B0-2BF

Table 1-1. PC I/O Addresses
FUNCTIONHEXRANGE
8237 DMA #1
2C0-2CF8259 PIC #1
2D0-2DF
8253 TIMER
2E0-2E78255 PPI (XT)
2E8-2EF
8742 CONTROLLER (AT)
2F8-2FFCMOS RAM & NMI MASK (AT)
300-30FDMA PAGE REGISTERS
310-31F
8259 PIC #2 (AT)320-32FNMI MASK (XT)378-37F
8237 #2 (AT)380-38F
80287 NUMERIC CO-P (AT)3A0-3AF
HARD DISK (AT)
3B0-3BBGAME CONTROL
3BC-3BF
EXPANSION UNIT (XT)
3C0-3CFBUS MOUSE
3D0-3DFALT BUS MOUSE
3E8-3EFPARALLEL PRINTER3F0-3F7EGA
3F8-3FFFUNCTION
EGA
EGA
GPIB (AT)SERIAL PORTSERIAL PORTPROTOTYPE CARD
PROTOTYPE CARD
HARD DISK (XT)
PARALLEL PRINTER
SDLC
SDLC
MDA
PARALLEL PRINTEREGACGASERIAL PORTFLOPPY DISKSERIAL PORTThe BASE switches can be set for an address in the range of 000-3F8 so it should notbe hard to find a free address. Addresses not specifically listed, such as 390-39F, arefree.

2.3 AC INPUT FILTER
The inputs are eight individual, optically isolated (500V) inputs that may be read backas a single byte. The inputs are not polarity sensitive and can be driven by either AC(input range −24V to +24V RMS, 50 to 1000 Hz) or DC (input range −24V to+24VDC). Each input has a switchable low-pass filter.
The switch which controls the input
filter is shown in Figure 2-2. From left
to right, the switches apply to inputs 0to 7. The diagram shows the low passfilter for inputs 0 and 1 enabled.
The filter must be used for AC inputs
and should be used for DC inputs.
Unless you have reason to turn off afilter, we recommend it be left on.

Figure 2-2. AC Filter Switches
3WARNING
High voltages will be present on the board when you haveconnected high voltage inputs or outputs to the connector.
Use extreme caution! Never handle the board when high voltage
signals are connected to the board.

43 REGISTER DESCRIPTIONS

3.1 INTRODUCTION
Two, eight-bit registers located at the base address (relay output) and base + 1(isolated inputs) are read or written to for control of relays, read back the state ofrelays or sense inputs (Table 3-1).
Table 3-1. Board Registers
BASE ADDRESSRELAY OUTPUT
READ/WRITEBASE + 0
Relay Outputs
BASE + 1
Isolated Inputs
Read Only
BASE + 2
Not Used
BASE + 3
Not Used
Although the PC104-PDISO8 decodes up to four addresses, two of those are not used.
This conforms to the design of the original PDISO-8, of which the PC104-PDISO8 isa true clone.
Please use the Universal Library if you are programming from a high level language.
The registers are written to and read from as a single 8-bit byte. Each bit controls anoutput or represents the state of an input.
Both registers are read left to right. The leftmost bit being the most significant bit.
Following this format, bit 7 of BASE + 0 corresponds to relay 7 and bit 0 to relay 0.
To construct a control word, refer to Table 3-2 for bit weights.

BIT POSITION
0
12345
6
7Table 3-2. Bit Weights
DECIMAL VALUE
124
8163264128

HEX VALUE1248
10204080

Example: To assemble a control byte with relays 0, 1, 3, 5, and 7 turned ON , refer toTable 3-3 for the coding.
5RELAY
76543210HEX80
4020108421Table 3-3. Control Byte Example
ON=1WEIGHTDECIMAL
180
1280064
120320016188004122111AB

ON=110101011WEIGHT
12803208021171

If the relay status byte is read back, it is in the same format.
The isolated inputs are read in this format as well. To disassemble the byte anddetermine the state of the isolated inputs or the relay read back register, perform thefollowing operation in software:

INPUT/RELAYINPUT 7/RELAY 7INPUT 6/RELAY 6
INPUT 5/RELAY 5
INPUT 4/RELAY 4
INPUT 3/RELAY 3
INPUT 2/RELAY 2
INPUT 1/RELAY 1
INPUT 0/RELAY 0

Table 3-4. Register Read-Back
HEX80
4020108421

DECIMAL12864321684213.2 OUTPUT REGISTER
The output register is located at the base address (BASE + 0).
WRITE = CONTROL: Write a byte to the register to control the relays. A one in therelay bit position turns the relay.
READ = STATUS: Read the status of the relay control register. A one in the relay
bit position indicates the relay is on.

6

3.2.1 ON & OFF for FORM C RELAYSy On means that FORM C relay common is in contact with the Normally-Open(NO) contact.
y Off means that FORM C relay common is in contact with theNormally-Closed (NC) contact.
3.2.2 ON & OFF FOR FORM A RELAYS
yyOn means that FORM A relay common is in contact with the Normally-Open(NO) contact.
Off means that FORM A relay common is open.

3.3 INPUT REGISTER
The isolated input register is located at BASE address + 1.
WRITE = NO FUNCTIONREAD = STATUS: Read the status of the isolated inputs. A one in the input bit
position indicates that a voltage is present at the input.
INPUT #BIT No.
HEXDECIMAL

7780
128

664064552032

44101673388224411220011

4 ELECTRONICS AND INTERFACING
This short introduction to the electronics most often needed by digital I/O board users
covers the following:
yyyyy

Connector diagram.
FORM C relay outputs.
FORM A relay outputs.
Isolated inputs.
Adding a resistor to expand the range of the isolated inputs.

4.1 I/O CONNECTOR
The PC104-PDISO8 use a single 40-pin connector. The pin-outs of the connector areshown in Figure 4-1. This connector can be converted to a 37 pin connector that iscompatible with the CIO-PDISO8 through the use of an adapter such as the BP40-37(Figure 4-2).

Figure 4-1. I/O Connector Pin Out

WARNING
High voltages will be present on the board when connected to highvoltage inputs or outputs. Use extreme caution! Never handle theboard when live signals are connected to the board.

8Figure 4-2. BP40-37 Pinouts

4.1 FORM C RELAY OUTPUTS
Figure 4-3 is the schematic for aform C relay, used at OP0 throughOP4.
The form C relay has a COMMON,
normally open (NO) and normallyclosed (NC) contact.
When a 0 is written to the output,
the common and NC are in contact.
When a 1 is written to the output,
the common and NO are in contact.
Figure 4-3. Form C Relay
The pin numbers shown in Figure 4-2 correspond to the 37 pin connector when using
an adapter such as the BP40-37 or the C40-37F-2 cable for relay #0.

94.2 FORM A RELAY OUTPUTS
Shown here is the schematic for a form A
relay, used at OP5 through OP7.
The form A relay has a COMMON and anormally open (NO) contact.
When a 0 is written to the output, thecommon and NO are NOT in contact. Whena 1 is written to the output the common andNO are in contact.

Figure 4-4 Form A Relay

The form A and form C relays are actually the same part number.
connections to the relay poles differ.

Only theThe Pin numbers shown in Figure 4-4 correspond to the 37 pin connector when using
an adapter such as the BP40-37 or the C40-37F-2 cable for relay #5.

4.3 ISOLATED INPUTS
There are eight optically-isolated input channels. The schematic of a single channel isshown in Figure 4-4.

OpticalIsolator
455 Ohm

Figure 4-4. Input Circuit - Simplified
Input signals are fed to a bridge rectifier so that the inputs are not polarity-sensitive.

10

4.4 EXTENDING THE INPUT RANGE
You can extend the input range beyond the ±24V specified by adding an external
resistor to the input. Use the following formulas:
Rext = 100 * (Vin - 24)
Resistor power rating = Pwatts = Rext / 10,000115 SPECIFICATIONSPOWER CONSUMPTION+5V supply

0.11 A typical with all relays off.
0.4 A typical with all relays on.

OUTPUT RELAY SPECIFICATIONS
Number
8Contact arrangement
5 form C, Relay 0 to Relay 4
3 form A, Relay 5 to Relay 7
Contact rating (resistive load)
0.4 A @ 120VAC or 2 A @ 30VDC
Contact resistance
0.050 Ohms max.
Coil resistance
125 Ohms
Operate time
5 ms
Release time
5 ms max.
Isolation
Between open contacts
1000VAC, 50/60HZ, 1 min.
Between coil and contacts
1500VAC, 50/60HZ, 1 min.
Life Expectancy
Mechanical
100,000,000 Operations
Electrical
500,000 Operations @ Full Load
ISOLATED INPUTS
NumberTypeRange
DCAC (50 to 1 kHz)
Input ‘High’ level
Input ‘Low’ level
Isolation
Resistance
Response
Filters
Time constant
Filter control

8Non-polarized, optically isolated (NOT TTLcompatible)
±24V
±24V
>5V min. (positive or negative input voltage)<2.5V max. (positive or negative inputvoltage)
500V
455 Ohms min
20 µs w/o filter
5 ms w/ filter
5 ms (200 Hz)
Each input individually switch-selectable

12

CONNECTORConnector typeDielectric Strength
Current Rating

ENVIRONMENTAL
Operating temperature
Storage temperature
Humidity

40 pin male header (optional cable available
to translate 40 pin connector to 37 pinconnector compatible with CIO-PDISO8)
1000Vrms
1A

0 to 50 deg. C−20 to 70 deg. C
0 to 90% non-condensing

13

For your notes.

14

EC Declaration of Conformity
We, Measurement Computing Corporation, declare under sole responsibility that theproduct:
PC104-PDISO8Part Number

Description

to which this declaration relates, meets the essential requirements, is in conformity
with, and CE marking has been applied according to the relevant EC Directives listed
below using the relevant section of the following EC standards and other normative
documents:
EU EMC Directive 89/336/EEC: Essential requirements relating to electromagneticcompatibility.
EU 55022 Class B: Limits and methods of measurements of radio interference
characteristics of information technology equipment.
EN 50082-1: EC generic immunity requirements.
IEC 801-2: Electrostatic discharge requirements for industrial process measurement
and control equipment.
IEC 801-3: Radiated electromagnetic field requirements for industrial process
measurements and control equipment.
IEC 801-4: Electrically fast transients for industrial process measurement and control
equipment.

Carl Haapaoja, Director of Quality Assurance

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