Return air temperature
In fan coils with a return air sensor (at B1), the controller must be configured
accordingly (see page 115).
– The temperature sensor in the room unit is ignored in this process (the signal is not
– A QAX34.1 room unit displays the value of B1.
The value of the local sensors (PPS2 and B1) can be corrected in the tools
(see page 140), but not the value of a bus sensor.
Temperature sensor outputs on the Konnex bus
To map the local temperature measurement in a building automation and control
system the following three output communication objects are used:
RXB... Room controller
The values of the communication objects Room temperature output and Return air
temperature output are unfiltered (not smoothed).
Sending takes place only if room "Room" is parameterized for the temperature sensor
The value transmitted as the Effective room Temperature is the filtered (smoothed)
value of the communication object Room temperature output or Return air temperature
output, or the average (see 7.1.3):
Room temperature output (Output communication object)
Effective room temperature (Output communication object)
Return air temperature output (Output communication object)
R W C T U
1 0 1 1 0 9.001
Invalid temperatures are mapped to the bus as 0 °C.
RXB (KNX) application library
Room tempearture output
Effective room temperature
Return air temperature output
FNC Description of functions for FC-10, FC-11, FC-12
Floating point (°C)
28 Feb 2009