iRSD-8R 8 channel Serial Relay & Daq Board

Serial Relay board for your projects.

Serial Relay Board for your projects.

Serial Relay board or COM port relay board is very useful when you want to control any AC or DC load through computer. The PC does not have any direct I/O ports such that you can control any pins which can be used to operate any load. For this you have to connect your PC to any such card which have got Serial Port or USB port on it.

This serial Relay board will connect to the PC through serial port and when proper commands are issued to the Serial relay board, it will operate the on board relays.

Iknowvations has got three kinds of Serial relay boards –

1. 2 channel serial relay board. : iRS-2R
2. 4 channel serial relay board. : iRS-4RD
3. 8 channel serial relay board. : iRSD-8R

iRS-2R serial relay board from Iknowvations

iRS-2R Serial Relay Board

4 channel RS232 relay board - iRS-4RD iknowvations

iRS-4RD 4 channel Serial Relay & Daq board.

iRSD-8R 8 channel Serial Relay & Daq Board

iRSD-8R 8 channel Serial Relay & Daq Board

All these boards are also having extra input/output pins that can be used to monitor external signals like outputs of Switch , Buttons or Sensors. These data can be monitored for controlling the on board relays through software or any program on PC.This program can be written any higher level language like VB, VC, C++, C# or Delphi. The program will continuously look for the signals on input pins of the connected serial relay card, test for the required conditions and as per condition, send the command for the operation of the relays.

Let us take a simple practical example. You want to control a light Bulb. The bulb should be ON when there is Dark and should be OFF when there is enough light. For this you will need a light sensor like LDR ( Light Dependent Resistor), connect it to a comparator IC which will get a High or Low output depending upon light condition. Connect this output to the input of serial relay card.

Monitor this input and depending upon the condition of this input pin, you can decide the relay output. The bulb has to be connected to one of the relays. For connection details you can go through any User manuals of the above mentioned cards. The User manuals can be downloaded from our download section at

The serial relay board described above is very easy to control. Just connect the card with serial cable to your PC. Open serial COM port using any Terminal program like Hyper Terminal or PUTTY and then apply 12 V DC power to the card. You will be greeted with welcome message and you are ready to go. Send appropriate command & the card will follow the commands.

For example if you want to make Relay1 ON, send RL11. To make it OFF send RL10. To see the list of commands, you have to go through the User Manual of the relevant card.

If you do not have serial port on your PC available or you want to operate relays through USB, we also have got USB based Relay boards like U96. Using this U96 USB Relay & Daq card, you can use relays and also you can use up to 36 I/O & analog channels.

If you require more information or any help for your project, please contact our support team at support(at) .

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