User Manual
CM2N8899en /01.05.02 Siemens Building Technologies
4/4 Building Automation
The following illustration shows a simplified example for coordination of central energy
handling with secondary plant demand (TEC) via the BPS. Heat generation and primary
air handling are coordinated:
TEC
FLN
RWI
BPS
@RWIx
TEC TEC
@TED
@TCRm
@TCRn
8899Z04en
Primary air handling
TSK
Heat gen.
Process
image
COLBAS
tasks
TSK
Coordination
TSK
Interface
Heat generation
Room
Room
These elements and functions are involved in coordination:
Element Functions
BPS Special COLBAS tasks (TSK) are involved in addition to the master
functions for TEC described above:
– Task "Coordination" gathers the TEC's process values, evaluates
them, and sends commands to its own "Heat generation" task as well
as to the RWI via the "Interface" task.
– The "Heat generation" task is a DDC program to control central heat
generation, which is connected to the BPS via the P-bus and the P-
bus modules.
RWI The RWI ventilation controller controls primary air handling.
TEC The TEC devices and data points provide key information:
– The TEC rooms contain detailed information on the supply air and
extract air volumes for the room and for each TEC controller as well as
the fan speeds for each TEC controller.
– The TEC groups contain the present operating conditions: (For
reasons of clarity, the groups are not shown in the illustration).
– The TED points indicate the specific energy demand of the associated
TEC controllers.
For the above example, the following process where the TEC energy demand values
control heat generation is a feasible scenario:
1. The rooms are too cold: The room temperatures are below the setpoint.
2. The heating valves in the cold rooms are opened more than 80%, without effect.
Þ
The flow temperature must be increased.
3. The BPS supervises the states and conditions. It determines the energy demand in
the TED point and sends a command to increase the flow temperature setpoint to
the "Heat generation" task.
Refer to the following documents for more information on this topic:
Document No. Title
CM2T8567E VISONIK system basics, topic 16 "TEC points in the BPS“.
CM2Z8303E BPS process image, volume 2.
Coordination to
HVAC main station
Example
Functions
Possible process
Additional information
2002 Siemens Building Technologies Ltd.