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  • 2-Digit LCD Display, Four Push-Buttons (up, down, mode, fan)
  • 1 On-Board Thermistor
  • 4 Universal Inputs (0-5V, 0-10V, thermistor, dry contact or open-collector)
  • 5 Digital Outputs (relay N.O.)
  • On-Board Temperature Sensor

The ST-35ER sets a new precedent in the LON industry with the first wall mount fully programmable controller with integral 2-digit display. The functionality of the ST-35ER is virtually limitless with its flexible I/O configuration. Typical applications for the ST-35ER include control of: AHU’s, Package Units, Heat Pumps, Fan Coil Units, Terminal Units, Unit Ventilators and VAV to name a few.

The ST-35ER is fully programmable via VisualControl Graphical Programming. Standard and custom applications can be easily modified and/or created graphically, without the necessity of learning Neuron C or line code programming with unique syntax. The flexible I/O configuration of the ST-35ER consists of a fully programmable end user interface with a backlit 2-digit LCD display and four pushbuttons. The functionality of the pushbuttons is completely flexible with the only limitations being the engraved labeling on the 4 buttons: up arrow, down arrow, mode, and fan. When the 4-pushbuttons are programmed to accommodate set point, override or fan control strategies, tremendous savings can be experienced as these are all software functions and do not require any additional devices to be purchased, installed and/or wired in the field.

Network connectivity is made easy with a discretely placed service pin pushbutton and service pin LED accessible at the top of the ST-35ER enclosure. The unit does not need to be removed from its base or wall, if wired, to establish a network connection.


Communication: LONTALK Protocol
Transceiver: FTT, Free Topology
Processor: Neuron 3150 @ 10 MHz
Memory: 64K bytes FLASH, 2K bytes SRAM (Neuron), 0.5K bytes EEPROM (Neuron)


Nominal Input Voltage: 24 VAC
Input Voltage Range: 21-28 VAC
Maximum Consumption: 8 VA, does not include Relay loading


Operating Temperature: 0 °C to +50 °C,, 32°F to 122 °F
Storage Temperature: -20 °C to +70 °C,, -4 °F to 158 °F
Relative Humidity: 5% to 95% (noncondensing)


Period: 2 Years (Limited)

Inputs (Internal)

Number: 1
Temperature Sensor: Onboard Thermistor
Accuracy: ±0.5 °C, ±1.0F (0 to 5 0 °C)

Jumper Selectable Inputs/Outputs

Total Number: 4
Input Options: Digital – Dry Contact, Voltage – 0-5 Volts
Thermistor – Type 2, 3: 10Kohms
Output Options: Voltage – 0-10 Volts
Analog Resolution: Input 12 bits, Output 10 bits
Accuracy: ±1% FS (25°C, 77°F)
Protection Circuitry: Transient Over voltage, ESD

Dedicated Outputs

Number: 5
Digital: Relay 1.0 A @ 24 VAC, Voltage Sourcing
Protection Circuitry: Transient Over voltage, ESD


Display: 2 Digit Backlit LCD Display
Dimensions: L 4.90” x W 3.13” x H 0.89”, (125 x 80 x 23 mm)


Standard model


10000 St Clair Avenue

Fairview Heights, IL 62208


(618) 394-0300