(up to) 4 x VMB4DC into a single DMX stream

Hello all,

Because I’m struggling to find din rail mains dimmers that support 0-10v control, I’ve been keeping an eye open for a simple way to get a DMX stream from Velbus.

While this solution isn’t the cheapest, it’s certainly really easy.

The concept is that we take the 0-10v outputs from VMB4DC modules (up to 4 of them, which gives us 16 channels) and wire those into a 16 channel DMX Multiplexer.

Something that I used to do in the early days of DMX when old lighting desks needed to be connected to new dimmer packs.
Zero88 used to sell a 36 channel DMX Multiplexer for such a task.

So I knew the concept was out there.

What I found was a lovely little Din Rail 16 channel DMX Multiplexer from SRS
srslight.com/index.php?index … ultiplexer]()

The only price I can find for it was on the German reseller’s site, at €191.35 Inc German sales tax.


The Belgian and Dutch resellers haven’t got the product listed on their sites

I know there are now other ways to get more DMX channels from a Velbus network, but for my needs, this looks like a very reasonable and tidy solution.

Good luck.


Ignore the DMX in, that’s only for firmware upgrading, which isn’t implemented as yet. (According to Jan at SRS customer support)


Sorry for kicking this very old post, but I have a question about Velbus/DMX/NodeRed functionality.
I bought a solution for connecting several DMX analog outputs to my velbus installation as virtual VMB4DC’s.
I’ve got 16 of this virutal velbus modules working.
What I have found, is that this module is actually a RPi configured with NodeRed.
But so far my knowledge. I can’t see anything in it as I don’t know how it works and maybe it’s been hidden or something as I payed for it as one working component.

The thing is, from time to time I had to pull the plug from the RPi to reset the module as there was some delay on the signals. But from today, I can’t access anything anymore.
It’s not working. I pulled the plug, even from the Velbus installation.
The modules aren’t recognized anymore.
The RPi is connected to my router, so I could connect to it via the IP address.
But it looks empty and I don’t know how to debug or fix it. :slight_smile:

I saw that you and @GertSt have a lot of experience with these modules.
So maybe you guys have a quick fix. Or even a way to improve the whole setup. :wink:
(Apparently some velbus actions aren’t supported at this moment :frowning: )

Thanks for any response! :slight_smile:


Thanks for reaching out to me (and Gert)

I’m really sorry to say that I haven’t had anything to do with that strange Pi based Velbus impressionist.
I did look at it to start with, but because it was based on a Pi, I moved way from that idea.

My setup uses lots of Art-Net / sACN adapters to DMX or SPI

I did start by using Jinx! to control the fancy lighting, with openHAB2 remotely controlling Jinx! and linking that to Velbus buttons etc

Currently, I’m doing the same with QLCplus instead (Where QLCplus is running on the same Linux device as openHAB2).

What would you like to do next?

Good luck


Hi Mdar,

I managed to get it working again. Don’t really know how I did it this time.
As I just pulled the plug again in a desperation attempt. :smiley:

I once started with a setup in OpenHab on my synology.
But with this RPi and now the Signum, there wasn’t a need to go through this setup.
So left it were it was, an untouched part of my Synology drives… :stuck_out_tongue:

As it is working again, I can continue as it is.
But if there are easy ways to simulate multiple VMB4DC’s and connect to a DMX Module, I might do it over myself. The interface of this NodeRed, looks quite intuitive.
But I don’t know the hardware, or how it was configures, so I don’t want to mess things up.

I really don’t want to set the house without lights for some time as it wouldn’t be appreciated… :wink:

Why is this RPi not a good idea?

Hi CrazyBird,

Pi has a weak spot on the storage/start SDcard; they most likely fail overtime.
So I advise you to access the sd-card (shutdown system first) and take a backup, just in case.

Good luck,

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Hi Ggaljoen,

Thanks for the tip, I’ll make sure to do this.
Or at least try to do it. :smiley: