DECISION COMPUTER INTERNATIONAL CO., LTD.

8 CHANNEL RELAY OUTPUT/PHOTO-ISOLATOR

Card Type

Data acquisition

Chip Set

NEC 8255

I/O Options

Opto-isolated input and relay control output port

Data Bus

8-bit ISA

CONNECTIONS

Function

Label

Opto-isolated input and relay control output port

CN1

CN1 PINOUT

Function

Pin

Function

Pin

Channel 1 relay open

1

Channel 4 relay open

20

Channel 1 relay common

2

Channel 4 relay common

21

Channel 1 relay closed

3

Channel 4 relay closed

22

Channel 2 relay open

4

Channel 5 relay open

23

Channel 2 relay common

5

Channel 5 relay common

24

Channel 2 relay closed

6

Channel 6 relay open

25

Channel 3 relay open

7

Channel 6 relay common

26

Channel 3 relay common

8

Channel 7 relay open

27

Channel 3 relay closed

9

Channel 7 relay common

28

Channel 8 relay open

10

Ground

29

Channel 8 relay common

11

Channel 1 negative

30

Channel 1 positive

12

Channel 2 negative

31

Channel 2 positive

13

Channel 3 negative

32

Channel 3 positive

14

Channel 4 negative

33

Channel 4 positive

15

Channel 5 negative

34

Channel 5 positive

16

Channel 6 negative

35

Channel 6 positive

17

Channel 7 negative

36

Channel 7 positive

18

Channel 8 negative

37

Channel 8 positive

19

   

OPTO-ISOLATION OPTIONS

Setting

JPxA

JPxB

Differential signals (+ and -)

Pins 1 & 2 closed

Pins 2 & 3 closed

Single-ended signals (+ and GND)

Pins 1 & 2 closed

Pins 1 & 2 closed

Single-ended signals, TTL levels

Pins 2 & 3 closed

N/A

Note:The exact locations of JP1A through JP8A and JP1B through JP8B are unidentified. JP1A and JP1B control the opto-isolation functions of channel 1. The settings for JP2A through JP8A and JP2B through JP8B are identical, controlling channels 2 through 8 respectively.

BASE I/O ADDRESS

Setting

SW1/1

SW1/2

SW1/3

SW1/4

SW1/5

SW1/6

SW1/7

SW1/8

 

000h

On

On

On

On

On

On

On

On

 

004h

On

On

On

On

On

On

On

Off

 

008h

On

On

On

On

On

On

Off

On

 

010h

On

On

On

On

On

Off

On

On

 

014h

On

On

On

On

On

Off

On

Off

»

2A8h

Off

On

Off

On

Off

On

Off

On

 

3ECh

Off

Off

Off

Off

Off

On

Off

Off

 

3F0h

Off

Off

Off

Off

Off

Off

On

On

 

3F4h

Off

Off

Off

Off

Off

Off

On

Off

 

3F8h

Off

Off

Off

Off

Off

Off

Off

On

 

3FCh

Off

Off

Off

Off

Off

Off

Off

Off

Note: Over 255 base address settings are available. The switches are a binary representation of the decimal memory addresses. SW1/1 is the Most Significant Bit and switch SW1/8 is the Least Significant Bit. The switches have the following decimal values: SW1/1=512, SW1/2=256, SW1/3=128, SW1/4=64, SW1/5=32, SW1/6=16, SW1/7=8, SW1/8=4. Turn off the switches and add the values of the switches that are off to 512 to obtain the correct memory address. (Off=1, On=0)

DIAGNOSTIC LED(S)

The functions of the LEDs are unidentified.