It would be nice if there was an example of ModBus Slave talking to real hardware

[jd-boyd]

This could be a GPIO or I2C device.

I'm guessing that the correct approach is to inherit ModbusRTU (or ModbusTCP) and then override functions like set_ist, set_coil, get_coil, etc.

[beyonlo]

Hi @jd-boyd

Yes, that will be nice.

Currently, how are you doing to get/set on the real hardware from the Slave, from/to the register_definitions? I'm still do not have reached this part, I still doing tests with the register_definitions, like this example, without to integrate with real hardware. I imagine that the best solution for now is a loop reading/writing from real hardware and updating/checking the register_definitions. As register_definitions is a dict, always that loop find a different value on the hardware, update the register_definitions dict, that will be what Slave will read. The same for write new value on the hardware, loop check if are there a different value on the register_definitions (that was set by Master), and write on the hardware. I really do not know what is the best solution.

[brainelectronics]

Big thank you to @beyonlo. You are the best support!

@jd-boyd I think you want something like using a coil as a GPIO, whenever it is physically modified the register value should be updated and if it modified by a Modbus Host, it's physical state should change. I might implement something like that on the weekend