User Manual

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Siemens RDF302 Basic documentation CE1P3079en
Smart Infrastructure 2020-02-21
· Room temperature control via built-in temperature sensor or external room
temperature / return air temperature sensor
· Changeover between heating and cooling mode (automatic via local sensor or
Modbus, or manually)
· Selection of applications via DIP switches or commissioning tool.
· Select operating mode via operating mode button on the thermostat
· 1- or 3-speed fan control (automatically or manually)
· Display of current room temperature or setpoint in °C and/or °F
· Display of outdoor temperature or time of day via Modbus
· Minimum and maximum limitation of room temperature setpoint
· Key lock (automatically, manually or via Modbus)
· 2 multifunctional inputs, freely selectable for:
– Operating mode switchover contact (keycard, window contact, etc.)
– Sensor for automatic heating / cooling changeover
– External room temperature or return air temperature sensor
– Dew point sensor
– Electric heater enable
– Fault input
– Monitor input for temperature sensor or switch state
· Advanced fan control function, e.g. fan kick, fan start, selectable fan operation
(enable, disable or depending on heating or cooling mode)
· “Purge” function together with 2-port valve in a 2-pipe changeover system
· Reminder to clean fan filters
· Floor heating temperature limitation
· Reload factory settings for commissioning and control parameters
· RS 485 Modbus (terminals +, - and REF) for communication with Modbus
compatible devices
2.4 Integration via Modbus
The RDF302, RDF302/VB and RDF302.B are communicative thermostat with
Modbus open protocol on RTU (Remote Terminal Unit) mode enabling easy
integration into BACS via RS-485.
The following Modbus functions are available:
· Central controls of room operating modes, setpoints, fan speed and fan mode
· Remote monitoring e.g. operating mode, control outputs, temperature sensor
or switch, etc.
· Alarming, e.g. external fault contact, condensation, clean filter, etc.
· Outside temperature or time of day via bus displayed on thermostat
· Key lock
Engineering and commissioning can be done using…
– local DIP switches / HMI
– via Modbus commissioning tool
Functions