Anyone have a Modbus register map?
Can't connect to input registers or holding registers with qmodmaster or modbus poll.
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The register map is unique to each device. It is usually defined in the communication section of the user manual specific to the product you have.
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Unless I'm missing something, I haven't it for the Opta yet.
Sorry, I think my previous response was a bit too brief.
If the registers you are trying to read are within the Arduino Opta (Opta acting as a modbus slave device), then your code will define the registers that are implemented for each function code.
I don't have specific experience of an Opta, only using an UNO as a modbus slave.
Are there any examples specific to Opta that Arduino provide that would give you a head start?
EDIT: I found this link that may help you:
I am using my Opta as a slave, and can write coils and read discrete inputs no problem using Modbus TCP - no code in sketch at all.
Same can't be said for the analog inputs (input registers I think?), and I don't think I would need lines of code just for analog values.
Thoughts?