User Guide

ViewStat Programming Protocol
17
ViewStat Communicating Thermostat - Programming Protocol Reference Guide
Thermostat Sensing Commands (Cont.)
Command Description
RxSy
Remote Sensor Value
(x=1-4, y=1,2)
Up to four addressable support-modules can be connected to a thermostat's local
communication network (LCN). Two sensors can be connected to each support mod-
ule. This value is used to retrieve the value of the sensor in the appropriate units of
measure. The 'RSM' command is used to determine what sensors of what type are
available on the thermostat LCN.
Syntax:
SN[address] RxSy?
Parameters:
•x = the support module address (1 - 4)
•y is the sensor number (1 or 2)
Reply Format:
SN[address] RxSy={value}F, C or %
Parameters:
•x = the support module address (1 - 4)
•y is the sensor number (1 or 2)
OT
Thermostat Remote
"Outdoor" Temperature
Up to four addressable support-modules can be connected to a thermostat's local
communication network (LCN). Two sensors can be connected to each support mod-
ule, each can be a temperature sensor or a humidity sensors depending on the sup-
port module model. Each sensor can be individually configured as control sensors or
remote sensors (for display only).
Sensor #2, configured to be "remote", of the support module with address #1 is the
source for remote outdoor temperature.
ViewStat responds with the temperature in the scale defined by the SCALE command
and appends a C or F to the value for clarity. Should no sensor be attached the value
will show "- -". This is the temperature value shown on the lower left of the thermostat
display and is the value used for high and low balance point control (for heat pump
use only).
The alternate command and reply formats have been implemented to maintain back-
ward compatibility with earlier thermostat versions.
Syntax:
SN[address] OT?
Reply Format:
SN[address] OT={value}F or C
Alternate Syntax:
SN[address] R?
Alternate Reply Format:
SN[address] R={value}F or C
OH
Thermostat Remote
"Outdoor" Humidity
Up to four addressable support-modules can be connected to a thermostat's local
communication network (LCN). Two sensors can be connected to each support mod-
ule; each can be a temperature sensor or a humidity sensor depending on the sup-
port module model. Each sensor can be individually configured as control sensors or
remote sensors (for display only). The humidity sensor configured to be "remote" of
the support module with address #1 is the source of remote humidity. ViewStat
responds with the humidity value appended by a "%" for clarity. Should no sensor be
attached the value will show "- -". This is the humidity value shown on the lower left of
the thermostat display.
Syntax:
SN[address] OH?
Reply Format:
SN[address number] OH={value}%