User Guide

Control Option Comparisons—Start/Stop Time Optimization (SSTO)
Siemens Building Technologies, Inc. 2-21
Heating Mode at Occupancy End
If the indoor temperature is greater than the desired temperature plus
one degree, then:
AE = AE - HA
Where:
AE = Adjust end time from SSTO command.
HA = Heating auto-tune coefficient (hcoef4) from SSTOCO
command.
If the indoor temperature is less than the desired temperature minus one
degree, then:
AE = AE + HA
Where:
AE = Adjust end time from SSTO command.
HA = Heating auto-tune coefficient (hcoef4) from SSTOCO
command.
APOGEE PPCL User’s Manual
2-22 Siemens Building Technologies, Inc.
Time-of-Day (TOD)
The Time-Of-Day (TOD) function is the software equivalent of the
time clock. TOD starts and stops equipment according to a defined
schedule.
Where to Use TOD
TOD can be used for running equipment on a scheduled basis. For
example, lights, doors (locking and unlocking), or exhaust fans.
CAUTION:
Be careful when designing your programs so that
functions do not conflict. If points used for TOD are
also commanded by another application, such as
Duty Cycling (DC), one program may interfere with
the operation of the other if both functions are trying
to control a point during the same time period.
Defining Time-Of-Day
The following PPCL commands are defined in the field panel for the
TOD function:
• TODMOD – Defines the types of schedules (normal, weekend,
etc.) for each day of the week. The TODMOD statement must be
defined first.
• HOLIDA – Used in conjunction with the TOD function to set
schedules for equipment during holidays. The HOLIDA command
must be placed before any TOD or TODSET commands.
• TOD – Commands up to 16 digital points ON or OFF at specified
times.
• TODSET – Sets the values of up to ten analog points at specified
start and stop times during the day.
The TOD and TODSET commands do not have to be defined in a
specific order.