This Python script allows for the control of an 8-channel relay board (model UD74B08) via a serial port connection. The script sends 8-byte commands, enabling users to toggle, turn on, turn off, interlock or momentarily activate relays connected to the specified COM port.

The project was developed out of necessity due to the limited documentation provided by the manufacturer, which required reverse-engineering the communication protocol. This script, along with its accompanying documentation, fills these gaps, offering a straightforward method to programmatically manage the relay module.

With minimal modifications, this code should also be compatible with other relay boards in the same family.

Refer to the external links for the complete code on GitHub and for purchasing the board.

I hope this is helpful to someone.
Cheers.