Operating Instructions

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Siemens RXB (KNX) application library RXB Description of functions for FC-10, FC-11, FC-12, FC-13 CM110385en_08
Building Technologies Control sequences 2013-06-17
Different applications support different valve actuators, and these do not all require the
same number of outputs on the controller.
Thermal actuators are driven with an AC 24 V PDM signal
Motorized actuators are driven with an AC 24 V 3-position signal.
Electromechanical actuators (motors with spring return) have a special PDM
algorithm that ensures that 50 position changes per day are not exceeded.
This causes a slower control behavior.
Proportional actuators are driven with a DC 0...10 V signal and supplied with AC 24
V by the RXB39.1 room controller via terminal G.
Thermal, electromechanical and DC 0...10 V actuators thus require one output,
motorized actuators two.
The table below shows the possible combinations:
System Actuator
type
Controller Outputs required
4-pipe fan coil (thermal)
RXB21.1
RXB22.1
Heating
Cooling
80261
Y1
Y2
(motorized)
RXB21.1
M
M
Heating
Cooling
Y1
Y2
Y3
Y4
80262
Electromech
anical
(ON / OFF)
RXB21.1
Heating
Cooling
Y1
Y3
M
M
RXB22.1
Heating
Cooling
Y1
Y2
M
M
Proportional
DC 0...10 V
RXB39.1
M
M
2-pipe fan coil (thermal)
RXB21.1
RXB22.1
Heating or cooling
80263
Y1
(motorized)
RXB21.1
RXB22.1
M
Heating or cooling
Y1
Y2
80264
Electromech
anical
(ON / OFF)
RXB21.1
RXB22.1
Y1
M
Heating or cooling
Proportional
DC 0...10 V
RXB39.1
M
Heating or Cooling
The room controllers also support the use of motorized EIB/KNX bus actuators. In the
tool, select Bus motorized.
Directly connected
valve actuators
Motorized
KNX/EIB bus actuators