Long velbus cabling


in my house we have installed a velbus system and it works great, but now we want to extend the system to the barn. its located about 80 meters from the house.

What would be the best way to connect the 2 velbus systems? in the barn we have at the moment only one relay module, but later on we will need to add input and more relays. But it would be nice if we could connect the 2 systems, so we can shut of the light in the barn from the house.



80m should be no problem.
With the right cable and properly placed terminators it should work.
The protocol can handle max cable length of 1km.

In case of trouble check if you have the latest VMBRSUSB module.
You can recognize at the power supply side of the module.
If you have 4 screw terminal you have the latest edition else you have an older version.

Best Regards

Should i put a second power supply at the barn and only extend the signal to there?

Or what is recomended for this?


If you use a high grade external CAT5e cable you should be able to connect buildings together.

According to the Velbus team, you should be able to achieve a maximum distance between your first and last module of over 1000 metres.

In theory, if you use the largest gauge DeviceNet cable, you could achieve over 3000 metres.

As for separating power supplies, that is always a good Idea.

All you need to do is create independent Velbus networks in each building (with unique base addresses).
When you’re happy with everything, just link the networks 0V, Data High and Data Low.

It’s vital to bond the 0V between networks to maintain a common reference for the data rails.

High or low is only relevant if it knows where normal (0V) is.

I’m putting in a system this week that uses 2 power supplies within the same building by simply running a loop cable with ;-

PSU 1 : 12V
PSU 2 : 12V
Common 0V
Data High
Data Low

Then balancing the power supplies by carefully selecting which modules are powered from each PSU.

Please let us all know how you get on with your project.

Good luck,