Application

Sequence of Operation
PPCL STATUS
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Siemens Industry, Inc.
BACnet LCM-OAVS, Application 6754
140-1325
2015-07-07
Room RH
RM RH displays the relative humidity value in percent. RM RH can be used for PPCL
in the PTEC or unbundled for control or monitoring purposes.
RM RH displays the relative humidity value in percent.
PPCL STATUS
PPCL STATUS displays LOADED or EMPTY.
 LOADED = PPCL - programming is present in the controller. A new application
number must be assigned (12000 through 12999).
 EMPTY = NO PPCL - programming is present.
The maximum number of PPCL dynamic points is 15.
Temperature Control Loop
Whenever the controller is in VAV control mode, the temperature control portion of
Application 6754 works as follows:
The controller adjusts the supply airflow and the reheat valve as necessary to maintain
CTL TEMP at CTL STPT. (When neither CTL TEMP nor CTL STPT is overridden, this
means the controller tries to maintain ROOM TEMP at ROOM STPT.) The temperature
control loop calculates the value of TEMP LOOPOUT. This value is used to sequence
the cooling flow and the heating valve. See the following figure. The loop is tuned by
adjusting the values of the feedback gains (ROOM P GAIN and ROOM I GAIN and the
sample interval, LOOP TIME.
Temperature Control Sequence.