User Guide

ViewStat Programming Protocol
15
ViewStat Communicating Thermostat - Programming Protocol Reference Guide
Thermostat Sensing Commands
These commands are used to inquire and set scale for the various temperature or humidity values
read by the thermostat
The following command descriptions describe the use of the command when setting a particular
variable. Inquiries can be made with all commands (with the exception of the
SCUP, SCDN, BLTON
and
ENTR commands) to determine the existing value of a variable. Inquiry is done using the
following syntax:
SN [address number, or <blank> or 0 (zero) for global] "COMMAND" ?
where COMMAND is the variable whose value is desired.
Thermostat Sensing Commands
Command Description
SCALE
Set Temperature Scale
Thermostat temperature readings can be displayed and communicated in either Cel-
sius (Centigrade) or Fahrenheit as dictated by this command. The setting at initial
power up will default to °F. Subsequent start-ups (i.e. loss of power or resets) will
default to the scale that was last set. Scale setting applies to the room temperature,
the remote temperature and all temperature settings. When a temperature setting is
to be communicated to the thermostat, and no scale is designated, the temperature
will be read using the scale that has been set for the thermostat.
Syntax:
SN[address] SCALE=F or C
Reply Format:
SN[address] SCALE=F or C
CT
Controller Type
Connecting an optional support module, configured for humidity control, to the View-
Stat changes it from a temperature controller to a humidity controller. Controller type
is a read-only command. This command is used to determine which ViewStat ther-
mostats connected to the network are currently acting as temperature controllers or
humidity controllers.
The response designations are CT=0, for temperature controller or CT=1, for humidity
controller.
Syntax:
SN[address] CT?
Reply Format:
SN[address] CT=0 (temperature controller) or 1 (humidity
controller)
TEMP
Thermostat Tempera-
ture
Thermostat temperature is that shown on the display of the thermostat and against
which the temperature settings are compared for control purposes. This temperature
can be from the thermostat's on-board temperature sensing element or from attached
support module(s) configured for temperature control. ViewStat responds with the
temperature in the scale set by the SCALE command. It appends a C or F to the value
for clarity.
Syntax:
SN[address] TEMP?
Reply Format:
SN[address] T={value}F or {value}C