Support Module Installation and Wiring
35
ViewStat Communicating Thermostat
1. Remove the thermostat from the sub-base.
2. Wire the first sensor using the single support module instructions. Daisy cha in the remaining support
modules as shown below (FIG. 29).
3. Set the VST-TTM or VST-TRH Support Module DIP switches as described in the following Setting the
Support Module DIP Switches section.
4. Replace the thermostat on the sub-base. Check for proper operation of each sensor.
Setting the Support Module DIP Switches
Both the VST-TTM and VST-TRH support modules contain a 6-position DIP switch (FIG.30) located on the
circuit board to set the support modules address, mode (monitor/contro l), and the temperature sensor source
(T1/T2 or Onboard Sensor). The ViewStat displays the temperature reading of whichever remote sensors are
connected to support modules in control mode. When multiple support modules are connected and in control
mode, the ViewStat displays an average of all incoming temperature readings. If all connected support
modules are set to monitor mode, then the ViewStat displays the temperature reading from the on-board
sensor, and the temperature from the remote sensor (or the average temperature if you’re using multiple
sensors) is displayed as the REMOTE temperature.
FIG. 28 Daisy-chaining VST-TTM Remote Temperature and VST-TRH Remote Temperature/Humidity support modules
To other support modules
(maximum of 4 total)
VST-TSF
Flush-mount Indoor
VST-TTM or VST-TRH support modules
ViewStat (faceplate removed)
remote sensor
VST-TSO
Duct/Outdoor
remote sensor
Always make sure that there is no power to the modules by removing the thermostat
from the sub-base.
FIG. 29 Daisy-chaining support modules
FIG. 30 VST-TTM or VST-TRH support module DIP switch
Thermostat Module 1 Module 2 Module 3 Module 4
RSR
RSC
RSB
RSA
RSR RSR RSR
RSC RSC RSC
RSB RSB RSB
RSA RSA RSA
RSR
RSC
RSB
RSA
1
2
3
4
5
6
ADDRESS
SPARE
T1/T2 (S1)
ADDRESS
MONITOR (S1)
MONITOR (S2)
ADDRESS
ADDRESS
CONTROL (S1)
CONTROL (S2)
SPARE
ONBOARD SENSOR
OFF ON