Ok, I have found several examples of using rs485 for a network, however what I dont understand is how the controllers are addressed.
Could anyone shed some light on that please?
I think what I have decided to "try" to make is a shield that incorporates the 485 communication, 4 relays, and a terminal block to connect some inputs ( digital, thermistor, and hopefully a 4-20ma or two)
The arduino's would only act as slave IO with all the logic being preformed by a python application on a PC.
This way the system could be used in several different applications.
Im kinda surprised that a similar shield doesnt exist