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  • 2-Digit Backlit LCD, Four Push-Buttons (up, down, mode, fan)
  • 4 Digital Outputs (relay N.O.)
  • On Board Temperature Sensor

The Smart Stat model 31 is a LonWorks® technology based thermostat controller using a Neuron® 3150® processor. Model 31 contains relays for local control of terminal units. It comes from the factory programmed to control a standard single stage rooftop unit. Other functional profiles can be downloaded into the thermostat for heat pump, multi-stage and user interface applications.

Factory programmed features include: local set point control with limits that can be changed via the network; four application control modes: auto, heat, cool, and off; manual fan control; network broadcast of local temperature, set point, and terminal unit status; set point, temperature offset, and control delta adjustment for the network; and button combination for logical installation.

The Smart Stat model 31 can be reprogrammed and has 56K bytes of user-programmable memory.


Processor: 3150 @ 10MHz
Memory: 56 Kbytes Flash EPROM, 2 Kbytes RAM (Neuron), 0.5 Kbytes EEPROM (Neuron)
Communications: LonWorks FTT-10A
Power Input: 21-28 VAC or 21-40 VDC
Environmental: 0 to 50°
Physical Dimensions: H 124mm xW 79mm xL 23mm, (4.9” x 3.125” x 0.925”)
Relay Output: 1A @ 24 VAC/DC max.

ST-30/31 – Model B

56K flash memory only

ST-30/31 – Model M

Standard model, selectable memory (flash, SRAM)

ST-30/31 – Model C

Real time clock with super cap back-up, selectable memory (flash, SRAM) and 8K serial EEPROM


10000 St Clair Avenue

Fairview Heights, IL 62208


(618) 394-0300