VT335i / Rack monitoring unit (legacy)

Release date: 06 April 2020

End-of-Life date: 01 December 2023

End-of-Support date: 01 December 2025

Documentation page: https://vutlan.atlassian.net/l/c/gTr18F3Q

Product page: https://vutlan.com/remote-monitoring-units/164-vt335i-monitoring-unit.html

Drivers: https://vutlan.atlassian.net/wiki/spaces/DRIV/pages/2701295618/Latest+Vutlan+drivers+for+VT855i+series+VT335i+VT825i+VT855i


Function and purpose

The unit is used for environmental monitoring (e.g. temperature, humidity, voltage, leakage, smoke, airflow). It is also used as an I/O controller (e.g. door control, fans, generator, control panels, UPS, circuit breakers, alarms). Can use up to 700 different elements - notifications, triggers, timers, logic schemes, sensors, and dry contacts. Has a built-in Web interface with virtual sensors, logic schemes, different types of notifications, and control panels. Has a slot for an LTE modem for an ethernet connection reservation.

VT335i is a new model and it replaces VT335S. New features include:

  • two times more powerful processor.

  • ability to handle more elements (+200)

  • slightly smaller dimensions

  • SD card

  • slot modem

  • power reservation

  • USB camera higher max. resolution

Physical Description

Front panel:

Back panel:

1. "Analog sensors: A1..A8" - x8 RJ12 6P4C analog sensor inputs with auto-sensing. Read instructions at "Analog sensors connection", and "Sensor configuration".

2. "CAN" - digital connector RJ12 6P4C for the connection of CAN sensors/extensions/devices on a CAN bus. Modules can be chained together. Read the instructions at "CAN devises connection and", and "Setting up CAN".

  • "LED: CAN" - green LED indicates CAN bus status.

  • The LED blinks slowly - nothing is connected

  • The LED blinks fast - configuration is in process

  • The LED glows constantly - connected to CAN devices

3. "LAN port" - Ethernet 10/100 Base-T port, provides an Ethernet connection. Read more in this section "LAN, GSM, LTE, RADIUS, DNS, SSL, VPN".

  • "Orange LED" - orange LED for Ethernet port. It shows network traffic.

  • "Green LED" - green LED for Ethernet port. It shows network traffic. Flashes green when the system starts up. Shows the connection state (constant green light - the connection is established, blinking green - the connection attempt).

4. "SD card" - MicroSD card slot with an ejector. The card is needed for data storage or the "system restore". Read instructions at "Saving system logs to SD card", and "Restore of the appliance (for VT960 series)".

5. "TEMPERATURE SENSOR" - accuracy +/- 1 °C.

6a. "LED: ACT" - green LED indicates appliance system status,

  • - operating mode of the device: switches at a frequency of 2 times per second;

  • - successful completion of the software update process: switches at a frequency of 4 times per second;

6b. "LED: ALARM" - The LED can be programmed from the interface for alarm indication.

6c. "LED: ERR" - red LED indicates error and traffic.

  • the operating mode of the device: If everything is normal, the LED is extinguished, if not - there's a constant glow;

  •  software update mode: switches at a rate of 2 times per second;

6d. "LED: CAN" - green LED indicates CAN bus status.

7. "USB" - micro USB-port 2.0 is needed for USB camera recording, USB Flash for system logs, and system restoration. Read instructions at "Connecting USB camera", "USB camera settings. How to save a video", "Saving system logs on USB flash drive", and "USB upgrade or restore of default settings".

8. "Dip switch

9. "OUTPUTS 12V 0.25A" - 12V 0.25A (for each output) terminals outputs (electronic relay). Pitch 3.81mm, 3P. Read instructions at "Connecting 12V devices to 12V outputs".

  • "LEDs: E1, E2" - status indicators for two 12V 0.25A outputs on the front panel.

  • The LED is ON (orange) - the output is ON (the initial state can be configured).

  • The LED is OFF (orange) - the output is OFF ((the initial state can be configured).

10. "Chassis grounding" - Chassis grounding, M4 thread. Enhances the immunity of the equipment against conducted and radiated RF disturbances. Please contact a professional electrician before connecting it.

11. "GNSS" - A hole for mounting the GNSS antenna. Antennas are purchased separately from VT335i and separately from VT740. Read more at GPS location, and GPS Service API.

12a. "Restart" - the button restarts the appliance. Hold the button for 2 seconds and then let go, and the system will restart.

12b. "Reset settings" - reset settings to default factory settings. Keep pressing the button for more than 5 seconds. The “ERR” LED will start blinking. This indicates that the factory restoration has started. Wait for 20-60 seconds for the system to restart. The “ACT” LED will start blinking once the system has been restarted. The device can be accessed now.

12c. "Factory reset" - Do not use this button. If you need a factory reset, please use the following optionhttps://vutlan.atlassian.net/wiki/spaces/DEN/pages/2417491974

13. "Modem slot" - "VT740 / LTE slot modem" can be installed in this slot. This modem is ordered separately. Read instructions at "VT740 / LTE slot modem", and "LAN, GSM, LTE, RADIUS, DNS, SSL, VPN".

14. "DRY CONTACT INPUTS 1...4" - Digital inputs (Type IN). Pitch 3.5mm, 6P. Read instructions at "Connecting dry contacts", and "Dry contacts settings".

15. "DC 12V BACKUP POWER" - 12V DC 2A alternative power input. Pitch 3.81mm, 2P.

16. "DC 12V POWER"- 12V DC 2A main power input.

Connection overview diagram

Drawing dimensions

Installing LTE slot modem



  1. VT124 / DIN rail holder” (also named DRP-03) for mounting on DIN rail. VT124 is ordered separately. The package includes a holder and screws.


2. “VT123 / Wall mounting brackets” for mounting onto the wall. The package includes 2 brackets and screws.


3. “VT122i / 19” holder” for mounting onto a 19” 1U rackmount.


Technical details


Vutlan s.r.o. (LLC)

Remote Infrastructure Monitoring and Control

43 ul.Svornosti, 821 06 Bratislava,

Slovak Republic