In conclusion, the Modbus 2-channel 5V relay module is a very useful device for making something Modbus compatible. I found the module relatively straightforward to use, and it seems to do a good job ...

The plan was to use the always-on 5V standby rail to drive a pair of relays. One relay senses the computer’s on/off switch and triggers the ATX power supply to turn on. The problem is the ...