Basic Documentation

15 / 42
Siemens VAV Compact Controller Modbus RTU A6V10631862_en--_e
Smart Infrastructure 2021-10-26
3.2.2 Demand-controlled ventilation (DCV)
In combination with a suitable supervisory room controller, an AHU control
optimization algorithm can be run using the actual value of the damper position
feedback signal.
The control of variable speed drives (VSDs) can be accomplished by various
means. Below depicted is DC 0...10 V control, but plants with Modbus RTU- or
BACnet MS/TP-controlled VSDs are also possible, depending on the connector
layout of the universal / primary controller.
Legend:
Bus Fieldbus (Modbus, BACnet, KNX etc.)
N1 Room unit with temp. sensor
N2 VAV Compact Controllers (supply / extract air)
N3 Universal / primary controller
N4 Variable Speed Drives (VSD)
~
Bus
T
MV
.
f1
f2
N3
Bus
M
M
~
f1
f2
MV
.
p
p
N2
N1
N2
DC 0...10 V
or Bus
Bus
Bus
N4
N4
Example: AHU control
optimization