Siemens Synco 200 - Implementation: Room-supply air temperature cascade controller

9.2.7 Implementation: Room-supply air temperature cascade
controller
9.2.7.1 Activating the cascade controller
The cascade controller can only be activated for controller 1, basic type A.
Activation
To activate room-supply air temperature cascade control, assign one input each to
the room and the supply air temperature and select control strategy CAS.
Also refer to subsection 9.2.1 ”Selecting the control strategy“.
If, in addition, input CAS/CON is assigned to a terminal, this input must be "0" for
cascade control.
Function of CAS/CON
input
You can use this input to configure changeover of the control strategy between
cascade and supply air temperature control:
Note
• Cascade control CAS/ CON = 0
• Supply air temperature control CAS /CON = 1 (for behavior, refer to
subsection 0)
9.2.7.2 Operating principle
The following diagram shows the operating principle of room-supply air
temperature cascade control:
Principle
T
T
TSu
TR
w
SpTSuC
SpTSuH
3101S38
CTLOOP 1
PI
PID
The main controlled variable is the room temperature TR; the auxiliary controlled
variable is the supply air temperature TSu.
The room temperature controller provides PI control, the supply air temperature
controller PID.
The result is a PI+PID room-supply air temperature cascade control process.
The room temperature controller sets the present setpoints SpTSuC and SpTSuH
for the supply air temperature controller within the selected limit values.
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Siemens Universal Controllers RLU2… CE1P3101en
Building Technologies Controller (CTLOOP x) 29.08.2008