Modbus and Temco newbie here, so my apologies in advance.
I am successfully reading from a Tstat7 on Linux via modbus RTU with mbpoll.
I am unable to write any registers - any time I issue a write command via the command line I get “Illegal data value: /dev/ttyUSB0” I have tried to write to dozens of registers like setpoints and modes.
I am trying to modify a setpoint - register: 345 - MODBUS_DAY_SETPOINT
Any advice to a newbie to get past this issue?
Thanks for writing Sam, I saw from your email that you are working under linux and I dont have someone here familiar with that. I did a quick search and see there’s the windows/linux modbus tool. Show us some screen shots & data captures for reading and writing modbus commands under linux and I can have our team mirror your tests under windows.