I am attempting to retrieve data from a SDM230 Modbus RTU Meter using a raspberry Pi running minimalmodbus (python3).
The response every time is:
Response from instrument: 01 03 02 00 00 B8 44 (7 bytes)
or if I request with read_float() four bytes:
Response from instrument: 01 03 08 00 00 00 00 00 00 00 00 95 D7 (13 bytes)
and the voltage value (register starts at 0) is 0.0.
Update 2023-05-23 22:16
I've found a posting for SDM220 Modbus Meter. The procedures/methods there are very similar to mine. This meter is a predecessor model of mine.
I can therefore not completely rule out that my measuring device has a quirk.
I have already contacted the supplier (B+G) and will update the question if I receive a response.