Application

Room Functions
Room Coordination Functions for HVAC
45
Siemens Industry, Inc.
Application Note
A6V11692053
Smart Infrastructure – Building Products
2019-04-01
Parameters
Description
Object
Preloaded value
Operating command for energy efficiency condition
trigger at automatic
1:None
2:Automatic
3:Manual
OpCmdEefAuto
2:Automatic
Operating command for energy efficiency condition
trigger at manual
Enumeration (see OpCmdEefAuto)
OpCmdEefMan
1:None
Display absolute room temperature setpoint
1:Average value
2:Present value
SpTRAbsDspy
2:Present value
Heating/Cooling State Determination
The Heating/cooling state determination (HCStaDtr) compares room
temperature to current setpoints and checks whether any HVAC devices are under
active PID control. The heating / cooling state is identified (Heating, Cooling, or
Neither) and supplied to the BACnet object HCSta. The H/C status is also
displayed on the room operating unit. Additional relevant BACnet objects (owned
by other AFs) are shown in the table below.
To change status by temperature, the room temperature heating/cooling
controllers must be inactive and the room temperature must be appropriate (high
enough or low enough) to activate the switch-on delay timer, DlyOnHCChovr
(Switch-on delay for heat/cool.changeover). See Configuration.
Description
Object
Pre-loaded Values
Room temperature setpoint shift
SpTRShft [RM TEMP SHFT]
0.0
Present cooling setpoint for comfort
SpCCmf [CMF CLG STPT]
75ºF (25ºC)
Delta cooling setpoint for pre-comfort
DSpCPcf [STBY C DELTA]
2ºF (1ºC)
Present cooling setpoint for economy
SpCEco [ECO CLG STPT]
85ºF (30ºC)
Cooling setpoint for protection
SpCPrt [PROT CLG STPT]
104 ºF (40ºC)
Present heating setpoint for comfort
SpHCmf [CMF HTG STPT]
70ºF (21ºC)
Delta heating setpoint for pre-comfort
DSpHPcf [STBY H DELTA]
2ºF (1ºC)
Present heating setpoint for economy
SpHEco [ECO HTG STPT]
55ºF (12ºC)
Heating setpoint for protection
SpHPrt [PROT HTG STPT]
45 ºF (7ºC)
Present cooling setpoint
PrSpC [CLG STPT EFF]
----
Present heating setpoint
PrSpH [HTG STPT EFF]
----
Present operating mode
PrOpMod [OP MODE EFF]
Comfort
Room operating mode
ROpMod [RM OP MODE]
Comfort
Plant operating mode
PltOpMod [PLANT OPMODE]
Comfort
Room temperature setpoint (for display on room unit)
SpTR [RM TEMP STPT]
----
Room temperature
TR [RM TEMP EVAL]
----