Commissioning - Basic Documentation - RDF302 - RDF302.B - RDF302/VB

Semi-flush mount room thermostats with RS485 Modbus communications RDF302, RDF302.B, RDF302/VB

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Thermostats (temperature controller with sensor)
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Technical Documentation > Basic Documentation
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The room thermostats are delivered with a fixed set of applications.

Select and activate the relevant application during commissioning using one of the following tools:

  • Local DIP switch and HMI

  • commissioning tools for RS485 Modbus RTU

DIP switches

Set the DIP switches before snapping the front panel to the mounting plate, if you want to select an application via DIP switches.

All DIP switches need to be set to “OFF” (remote configuration), if you want to select an application via Modbus commissioning tool.

After power is applied, the thermostat starts with all LCD segments flashing for about 3 seconds. Then, the thermostat will be at normal display mode and is ready for commissioning by qualified HVAC staff.

If all DIP switches are OFF, the display reads "NONE" to indicate that application commissioning via a tool is required.


Each time after a different application is selected, the thermostat reloads the factory settings for all control parameters EXCEPT the parameters for communication settings. e.g. device addresses (P81), Baud rate (P68) and Parity (P70)

Control parameters

The thermostat's control parameters can be set to ensure optimum performance of the entire system. The parameters can be adjusted using

  • Local HMI

  • commissioning tools

The control parameters of the thermostat can be set to ensure optimum performance of the entire system (see section 3.13, control parameters).

Control sequence

  • The control sequence may need to be set via parameter P01 depending on the application. The factory setting is as follows:

Application Factory setting P01
2-pipe and chilled / heated ceiling 1 = cooling only
4-pipe, chilled ceiling and radiator 4 = heating and cooling

Compressor-based applications

  • When the thermostat is used with a compressor, adjust the minimum output on-time (parameter P48) and OFF-time (parameter P49) for Y11/Y21 to avoid damaging the compressor or shortening its life due to frequent switching

Calibrate sensor

  • Recalibrate the temperature sensor if the room temperature displayed on the thermostat does not match the room temperature measured (after min. 1 hour of operation). To do this, change parameter P05

Setpoint and range limitation

  • We recommend to review the setpoints and setpoint ranges (parameters P08…P12) and change them as needed to achieve maximum comfort and save energy