Siemens RDG20 KN Series - Page 104

Functions
Control outputs
4
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A6V11545892_en--_e
The demand calculated by PI control from the current room temperature and
setpoint is provided via Y10, Y20, Y30 and U1 (RDG2..KN: U1, for 4-pipe/2-stage
applications) to the valve actuator as a continuous DC 0...10 V signal.
● Parameter P256 (RDG264KN only), P260 & P261 (RDG26..KN) sets the
heating flow limitation if PICV is installed at output for heating and cooling. See
Additional functions [➙ 48].
● For P-band (P050, P052, P054), see Control sequences [➙ 77].
● The demand calculated by PI control from the current room temperature and
setpoint is provided via Y20 as a continuous DC 0...10 V signal
● The signal converter (SEM61.4) converts the DC 0...10 V signal to AC 24 V
PDM pulses for the current valve
● The current valve (SEA45.1) supplies the electric heater with pulsed current
The electric heater can be controlled via the On/Off control output (Q2) by setting
P203 or P204 to 4. For adaptive temperature compensation, see 2-pipe fan coil
unit with electric heater [➙ 81].
N1 RDG26..KN
C1 Signal converter
SEM61.4
(see Data Sheet N5102)
Y1 Current valve SEA45.1
(see Data Sheet N4937)
K… Safety loop (e.g. safety
thermostat and high-
temperature cutout)
FF Very fast-acting fuse
F… Overcurrent trip
The RDG26.. can control a 6-port control ball valve that provides heating and
cooling within one DC 0…10 V or DC 2…10 V signal.
These 2 signals allow for controlling Siemens valves as well as DC 2…10 V valves
by other suppliers.
For the same application, RDG26.. can also provide an inverse signal DC 10…0 V
or DC 10…2 V signal for inversed hydraulic connections on the valve.
The selection of the signal is set with P201.
Description
Explanations
P201 = 6
6-port valve (DC 0…10 V control
signal)
Suitable for Siemens and competitor 6-port control valves
and actuators with DC 0…10 V signal
P201 = 7
6-port valve (DC 2…10 V control
signal)
Suitable for competitor 6-port control valves and actuators
with DC 2…10 V signal (e.g. Belimo)
P201 = 8
inverse signal, 6-port valve
(DC 10…0 V control signal)
Useful for inversed hydraulic connection on the 6-port
control ball valve with Siemens or competitor DC 0…10 V
actuator*
P201 = 9
inverse signal, 6-port valve
(DC 10…2 V control signal)
Useful for inversed hydraulic connection on the 6-port
control ball valve with competitor DC 2…10 V actuator (e.g.
Belimo)*
* Inverting the signal might cause hydraulic balancing issues
DC 0...10 V
for valve actuators
Note
DC 0...10 V
for electric heaters
Note
DC 0...10 V
DC 2…10 V
for 6-port control ball
valve (RDG26.. only)