To control an indoor unit individually via the RTD-10 and using hardwired connections, operate the RTD-10 in Standard mode - Resistance or Voltage (only either of these modes can be selected, i.e. mixed Resistance and Voltage control is not possible).
Set the RTD-10 DIP Switches as described on pages 8 and 9 in the installation instructions (attached below). If no Modbus control or monitoring is needed then the DIP switches 5 -8 can be set to OFF position, otherwise these DIP switches are used to set the Modbus network address of the RTD-10 interface.
To switch the indoor unit On or Off, or to control any other parameter, follow the instructions on pages 8 or 9 in the installation instructions.