User Manual

Page 14
The Modbus data is provided in Addendum 1 at the back of this manual. (page 18).
Modbus relies on a series connection and will normally not tolerate “Star” wiring or “T” branches.
Remote Temperature sensors
Occasionally the room thermostat cannot be installed in
the ideal location to measure the room temperature
accurately. In these circumstances the SMT-131 can use
optional remote temperature sensors. These are a two-
wire resistive device,(10K Type II NTC) not polarity
dependent and simply wired into the SMT-131 sensor
inputs terminals (“SI” and “Com 0-V”). Depending on
installer menu sensor settings, (shown on page 17),
remote sensor(s) will either override the SMT-131
onboard sensor or average with the onboard sensor.
Multiple sensors can be used for averaging over larger
areas if necessary.
Wireless (RF) remote sensors are also available if fixed
wiring cannot be installed economically. (P/N RS-W).