How can I monitor the indoor unit with the RTD-RA?

The RTD-RA ONLY allows monitoring the indoor unit via Modbus. 

The RTD-RA does NOT have output relays. S1 and S2 are inputs for setting the RTD-RA mode of operation. They are NOT outputs.

 

Exception: When RTD-RA is operated as Duty/Standby Slave. For further information see: