Setpoint Calculation; Description - Siemens Desigo RXB Technical Manual

Siemens
Building Technologies
6

Setpoint calculation

6.1

Description

• Each room controller has 9 different room temperature setpoints :
One heating and cooling setpoint for the room operating modes Comfort, Precomfort,
Economy and Protection as well as a Frost limit value.
• The setpoints
– are defined in the tool during engineering.
– runtime- adjusted by the communication objects (DESIGO, Synco)
This does not apply to the Protection setpoints and the frost setpoint (page 33).
• The setpoints are shifted
– Centrally via KNX bus from the building automation and control system
(only Comfort , Precomfort and Economy ).
– Locally via PPS2 by a room unit or a setpoint adjustment unit
(only Comfort and Precomfort ).
– The controller controls the values internally to ensure that sensible periods are
adhered to between the various room operating modes.
• The result is 8 present setpoints.
• The effective room operating mode selects one setpoint each for heating and
cooling from the 8 setpoints.
These are the effective setpoints to which the controller executes control.
Define
Tool 6.2 Runtime 6.3
KNX
Comfort heating setpoint
Comfort cooling setpoint
Precomfort heating setpoint
Precomfort cooling setpoint
Economy heating setpoint
Economy cooling setpoint
Protection heating setpoint
Protection cooling setpoint
Frost setpoint
KNX
PPS2
DI
RXB (KNX) application library
Setpoint calculation
Centrally 6.4
KNX
Central setpoint shift heating
Central setpoint shift cooling
Effective
room operating mode
Effective heating setpoint SpH
Effective cooling setpoint SpC
FNC Description of functions for FC-10, FC-11, FC-12
Shift
Locally 6.5
PPS2 KNX
Local setpoint shift
KNX
8 present setpoints
KNX
H C
CM110385en_05
(6.1.1)
KNX (6.1.2)
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28 Feb 2009