User Guide

Table Of Contents
Command Syntax
Siemens Building Technologies, Inc. 3-99
SSTO (Start/stop time optimization)
Unitary pre-APOGEE APOGEE BACnet
Syntax
SSTO(zone,mode,cst,csp,est,lst,ost,esp,lsp,osp,ast,asp)
NOTE: Valid mode values are described in the table following the
parameter descriptions.
zone SSTO zone number.
Valid values are 1 to 5.
mode Mode number.
Valid entries are any combination of 1, 2, 4, 8, or 16
as defined in the following table.
Mode numbers can be added together to create
customized schedules for the TOD program. See the
TODMOD command for more information.
cst Calculated start time.
This parameter is a virtual LAO point name.
If SSTO is disabled (season = 0 in the SSTOCO
command), then cst is assigned to the latest start
time.
csp Calculated stop time.
This parameter is a virtual LAO point name.
If SSTO is disabled (season = 0 in the SSTOCO
command), then csp is assigned the latest stop time.
est Earliest start time.
This parameter can be a military time (7:30 p.m. =
19:30), a decimal time (7:30 p.m. = 19.50), a logical
point name, or a local variable.
lst Latest start time.
This parameter can be a military time (7:30 p.m. =
19:30), a decimal time (7:30 p.m. = 19.50), a logical
point name, or a local variable.
ost Occupancy start time.
This parameter can be a military time (7:30 p.m. =
19:30), a decimal time (7:30 p.m. = 19.50), a logical
point name, or a local variable.
APOGEE PPCL User’s Manual
3-100 Siemens Building Technologies, Inc.
esp Earliest stop time.
This parameter can be a military time (7:30 p.m. =
19:30), a decimal time (7:30 p.m. = 19.50), a logical
point name, or a local variable.
lsp Latest stop time.
This parameter can be a military time (7:30 p.m. =
19:30), a decimal time (7:30 p.m. = 19.50), a logical
point name, or a local variable.
osp Occupancy stop time.
This parameter can be a military time (7:30 p.m. =
19:30), a decimal time (7:30 p.m. = 19.50), a logical
point name, or a local variable.
ast Total adjustment to the calculated start time. This value is
changed from day-to-day.
A decimal value or virtual LAO point type can be
defined to store the adjustment value.
asp Total adjustment to the calculated stop time. This value is
changed from day to day.
A decimal value or virtual LAO point type can be
defined to store the adjustment value.
Valid SSTO Mode Values.
Mode Schedule
1 Normal schedule
2 Extended schedule
4 Shortened schedule
8 Weekend schedule
16* Holiday schedule
*Mode number 16 (Holiday) should only be used with the HOLIDA command.
Use
The SSTO command calculates the optimal start and stop times for
each zone based on information derived from the SSTOCO
command (outside air temperature, zone temperature, desired zone
temperature, etc.) as well as parameters for earliest, latest, and
occupancy start times provided in the SSTO command.
This command has the ability to tune itself by incrementing or
decrementing the start time after calculating an adjust time (ast)