The thermostat supports the communication protocol (Modbus RTU mode) as per the Modbus specification (see

Device address

The device address is assigned to "1" (factory setting). If necessary, engineer/installer can change the address value using the parameter P93.

Baud rate

The Baud rate is selectable. Four options, auto, 9600 bps, 19200 bps and 38400 bps, are available for the Modbus network (19200 bps is default).

Modbus data frame format

Modbus data frame format can be set to 1 = 1/8/E/1, 2 = 1/8/O/1, 3 = 1/8/N/1 or 4 = 1/8/N/2 (1/8/E/1 is default).