The 8 channel relay output / isolator input board provides relay output function and isolator input function. The relay output part provides 8 Single Pole Double Throw (SPDT) relays to drive 8 digital output lines. Each relay channel can be used to control ON/OFF of external devices, to drive external high power relays, to activate alarms¡Ketc. There are 8 LED indicators correspond to 8 relays, when relay is energized, the corresponding LED is light. The +12V power source is user selectable from internal PC bus or external power supplier.

The isolator input part provides 8 Photo isolated Digital Input Channel, which allow the input signals to be completely floated and prevent the ground loop. There are 8 LED indicators corresponds to 8 input channels, when the input channel is activated at high stat, the corresponding LED is light. The power source is user selectable from internal PC bus or external power supplier.

The features of 8 Channel Relay Output / Isolator Input Board are :

1. Relay Output Function.
#Support 8 SPDT relay channels.

#LED indicates when relay is energized.

#Internal and external power selectable.

#Built in screw terminals for easy writing.

#The Normal Open (NO), Normal Close (NC), and Common contacts (COM) of each relay are brought out to the screw connector.

#Max contact rating: 150V/DC 2amp, 125V/AC 2amp.

#Breakdown voltage: AC/DC 500V minimum.

#Relay on time: 3 ms typical.

#Relay off time: 2 ms typical.

#Isolation resistance: 100 ms typical.

#Life expectancy: 5 million operation at full load.

#Screw terminal: accept #22 to #12 awg wire.

#Power consumption.

+12V: 40mA for each relay, total 0.55 amp for all relays are energized.
+5V : < 0.2 amp.
-12V : < 0.1 amp.

2. Isolator Input Function
#Support 8 opto-isolated input channels.
#LED indicated when input channel is activated.
#Internal and external power selectable.
#Built in screw terminals for easy wiring.
#Allow the input signals to be completely floated and prevent the ground loops.
#Isolated or non-isolated modes selectable.
#Input signals are buffered with voltage comparators.
#Input threshold voltage adjustable.
#Breakdown voltage: 1500 VDC.
#Screw terminal: accept #22 to # 12 awg wire.
#Input current: 80mA maximum for each isolated input.
#Input voltage: 30VDC maximum for each isolated input.

Hardware Installation:

Configuration For Jumper And Adjust VR

Before you use the 8 Channel Relay Output/ Isolator Input Board, you must ensure that the power supplier, jumpers, and connectors are set correctly. Observe the figure in the following, the proper settings for the 8 Channel relay Output / Isolator Input Board are described in the follows.

Setting the threshold voltage of Photo Isolator, adjust VR which is on the PCB to get the desired threshold voltage. The external input voltage which is over the threshold voltage will be recognized as HIGH (1) and the relative led will be light. Otherwise that will be LOW (0) and led be off.