The parameter confirmation function is selected for the 485 functions refers to the manual
The default address of the instrument is 001, baud rate 9600, n without parity, 8 bits of data, 1 bit of stop
Is the instrument wired correctly, connect 24V COM 485A 485B, battery power supply and two-wire system do not support 485 functions, confirm 24V power supply is normal
The instrument communication is based on the MODBUS RTU protocol.
Communication register address needs to be offset by 1 bit if using a software device such as a PLC, e.g. 0004, then use 0005