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Siemens
RXB (KNX) Applications library
CLC and RAD description of functions for CC-02 CM110384en_03
Building Technologies
Setpoint calculation
28 Feb 2009
In LTE-mode, the central setpoint setting is transmitted via the following communication
objects (triplets):
Setpoints heating (input)
Setpoints cooling (input)
Possible
partner
function blocks)
Known partner devices
TempRoomSetpSetHeat
TempRoomSetpSetCool
Geographical zone
Siemens SBT proprietary
Siemens:
Synco RMB795
Setpoints changed by a tool (e.g. HandyTool) are overwritten by PX-KNX during room
controller startup!
6.4
Central setpoint shift
The
Comfort, Economy
and
Precomfort
setpoints can be adjusted separately for
heating and cooling centrally from the BACS.
Central setpoint shifts are used particularly e.g. for summer/winter compensation.
Summer/winter compensation causes a gradual increase in room temperature as a
function of the outside temperature. This prevents too great a difference between the
indoor and outdoor temperature in summer and increases overall comfort in winter.
Normally, only Comfort and Precomfort values are shifted.
The room controller corrects the setpoints resulting from central shift by applying the
following rules
•
Comfort setpoints:
The value for the spacing must not be below the original value
A
.
•
Precomfort setpoints:
The value for the spacing to Comfort setpoints must not be below the original values
B
.
Winter compensation Original Summer compensation
values
Setpoints
Protection
cooling
Economy
cooling
Precomfort
cooling
Comfort
cooling
Comfort
heating
Precomfort
heating
Economy
heating
Protection
heating
1
038
5D
10
7
Sp [°C]
T
OA
A
B
STOP
Important!
Management station
Summer/winter
compensation
Internal correction by
controller
Example