VT408 / Analog sensor extension unit

Product page: https://vutlan.com/extension-boards/175-vt408-sensor-extension-unit.html

Datasheet page: https://vutlan.atlassian.net/wiki/spaces/DEN/pages/2882535425/VT408+Extension+unit+v16.1

Function and purpose

Increases the number of analog sensors connected to any Vutlan monitoring unit. Each unit connected adds 8 analog sensors. Connects on CAN port and allows further CAN daisy chain connection. Sensors connected to the extension unit appear in the system automatically.

Up to x24 VT408 units can be connected on a CAN bus line. CAN-12V-1A / CAN Power Supply has to be used to provide additional power on a CAN bus line.

Physical description

1. LEDs: "RUN" - indicates appliance connection status to the main module, "ERROR" - indicates appliance lost connection to the main module.

  • ERROR is lit continuously, RUN blinks - the unit has no connection with the monitoring unit.

  • ERROR is continuously lit, RUN repaid - extension unit communicates with a monitoring unit, however, it is not included in the monitoring system (not configured).

  • ERROR repaid, RUN lights up continuously - the extension unit is included in the work as part of a monitoring system.

  1. "A1..A8" - 8 RJ12 analog sensor inputs with auto-sensing.

  2. "TR" - If VT408 is the last unit in a CAN bus chain or if it is connected in a CAN bus chain longer than 10 meters, the terminator should be in the "TR" position (switched to the left). Otherwise the “TR” should always be switched to the right.

  3. "CAN1 CAN2" - two equivalent digital connectors RJ12 for the connection to the master module, CAN sensors, or CAN extensions on a CAN bus, with auto-sensing.

  4. "Power" - for connection of external power supply 12V DC.



The VT408 expansion module has two RUN (green) and ERROR (red) LEDs that show the following states:

  • ERROR continuously lit, RUN flickers - the expansion module has no connection with the master module

  • ERROR is continuously lit, RUN is extinguished - the expansion module has communication with the master module, but is not included in the monitoring system (not configured)

  • ERROR is extinguished, RUN is continuously lit - the expansion module is included in the monitoring system



Product dimensions

Size W 129 x H 28,6 x D 56 mm


Packaging weight

0.5 kg


Inputs terminals

x8 analog sensor ports

x2 CAN ports RJ-12


Operating temperature

Temperature: Min. -10° C - Max.+80° C


Mounting possibilities

VT123 / Wall mount brackets (ordered separately)

VT125t / 19” 1U Mounting kit for x2 VT408 units (ordered separately)


Max. distance from the unit

Max. bus length: 225m,

Max. length of analog sensor cables: 50-150m (depends on sensor type)


Manufactured in (country)

Manufactured in Slovak Republic, E.U.


HS Code

8471 50 000


Extension protocols



Network Interface

CAN open


Status Indicators

Red (Error) / Green Led (Run)

Mounting: Wall mount

  1. There are x4 M3 thread holes at the bottom of the case. You can mount ‘VT123 / Wall brackets’ to these holes and then use them to mount onto the wall or surface. ‘VT123 / Wall brackets’ are ordered separately.

Mounting: DIN rail mount

There are x2 M4 thread mounting holes at the bottom of the unit. Use them to mount the ‘DRP-03 VT124 / DIN rail holder'. It can then be used to attach the device to the DIn rail.

‘DRP-03 VT124 / DIN rail holder' is purchased separately. You can also purchase it at TME.eu.

Mounting: 19” 1U rack mount

It is possible to use a ‘VT125t / 19-inch 1U mounting bracket’ to mount x2 VT408 units in one 1U rack space. "VT125t / 19" bracket" is purchased separately.

  1. The mounting kit consists of two parts.


  1. If you need to install the second VT408 onto VT125t bracket by unscrewing two M3 screws.


  1. VT125t parts unassembled.


  1. Use M3 screws to fix VT408 on the VT125t trays.


Connect the CAN input of the unit by RJ11/RJ12 cable supplied to the CAN input of the previous CAN unit or monitoring system. The red LED lights up. Match the TR bus terminators on the attached CAN units. CAN bus terminators TR (position 2 in VT450) should be in the ON state only at the end CAN units port and in Off states (1,2) for all intermediate units. One CAN bus can have not more than 8 CAN units, sensors, and/or another CAN device. 

Normally 12V 0.5A external power supply is connected to the jack labeled PWR (point 2 in the general scheme). But if the only VT408 unit is connected and the length of the cable from the monitoring unit to the VT408 does not exceed 10m the extension unit operation without any external power supply. In all other cases, the use of an external power supply is desirable.

Example connection

Setting up CAN

Configuring VT408



Vutlan s.r.o.

Remote Infrastructure Monitoring and Control

43 ul.Svornosti, 821 06 Bratislava,

Slovak Republic, E.U.