Can anyone tell me if a custom RS485 protocol can be implemented on Opta? I'd like to try communicating with my pool pump, similar to this user Trying to communicate with a Pentair pool pump via RS485 with no luck yet - #43 by keithco. The pump uses RS485 but not the modbus protocol.
AS RS-485 is an electrical standard, and protocol is a data/logical design, the answer is yes, any logical protocol can be used with the RS-485 standard. But you need to have a complete documentation for the proposed protocol and that seems to be missing for your pump mechanism.
That is not hard to do but it needs to be the same as the other end or they will not yield acceptable results. Defining the protocol can take a lot of time.