Room temperature measurement
The value valid for temperature control can originate in various sources:
– A room unit via PPS2
– An analog sensor via analog input B1
– Mean value of several sensors
– The bus.
If none of these sources supplies a valid room temperature, the following will happen:
• the controller uses the mean value from the effective heating and cooling setpoints
for control until a valid measured value is again received
• the controller issues an alarm "Room temp. sensor error"
• the bus output sends 0°C
• if slaves are connected, they receive an invalid temperatur (327.67°C)
• if a room unit is connected to a slave, the slave uses the temperature value of its
room unit when two heartbeat periods have elapsed.
Local temperature sensor at PPS2 interface
PPS2 (CP+, CP-)
Local temperature sensor at analog input
The sensors connected to terminal B1 can have different functions:
Only measured value
RXB (KNX) Applications library
If a QAX... room unit (with PPS2 interface)
is connected to the controller, the room
temperature is measured by the
temperature sensor integrated in the room
Alternatively, an LG-Ni1000 sensor, type
QAA24, can be connected to analog input B1
of the room controller.
Room air sensor (can also be used for averaging
together with room unit PPS; see below).
No sensor connected.
Uses the signal, see "analog input B1", page 112.
CLC and RAD description of functions for CC-02 CM110384en_03
28 Feb 2009