[SOVLED] How to convert 3 dimmers RGB to colorpicker?

That might be an error in the binding

I don’t use the one that is installed from PaperUI (*now that you point it out)

Try this one


If I change colorpicker (Color, Brightness, Saturation) in PapperUI in Control tab - then dimmers does not changes : (

Here is my DMX dimmer settings in PapperUI:

  • Which profile did you use to link them?

  • What happens to the colour picker if you adjust the separate RGB dimmers?

I delete old binding and install your binding.
I try diferend profiile: default and follow.

Nothing happens. colorpicker doesn’t change.

Here is a video:


My apologies.

I’ve found the reason for why my setup does reflect the changes of the independant channels and yours (currently) is not.

I have chases setup that use the same channels and I have seen the ColourPicker change, when the chase/s are running.

So this morning, I added 3 x seperate DMX Dimmer Things (one for each colour), using the same DMX channel.

For example.

My Colour Picker uses DMX channels 508/3 (508,509 & 510)

The chases also use 508/3

I have added

  • Red - Channel 508 - Linked to the same Item as used in the Colour Picker (not for any reason that to try)
  • Green- Channel 509 - Linked to the same Item as used in the Colour Picker
  • Blue - Channel 510 - Linked to the same Item as used in the Colour Picker

I can report that adjusting these Dimmers does change the colour picker :slight_smile:

This short video shows it all in action

I have bridge offline : (
And nothing helps launch it : (

I must say I think this might be a problem here.

1 Like

Your Art-Net bridge is showing as Unknown in that screenshot, previously it was On-Line

Do you need to restart openhab (or that bundle) so that the Bridge uses the new version of the binding?

Or just create a new Art-Net / sACN bridge with JNK’s updated binding?

What is a “color channel”?
Is this an empty linked variable?

Can you be a little more specific with your question please ?


Dimmer fix1r "Fixture 1 red   [%.0f]" (gStreetDMX_GR1_r){ channel="modbus:data:beckhoff:DMXstreetlamps1_123:fix1r:dimmer" } 
Dimmer fix1g "Fixture 1 green [%.0f]" (gStreetDMX_GR1_g){ channel="modbus:data:beckhoff:DMXstreetlamps1_123:fix1g:dimmer" }
Dimmer fix1b "Fixture 1 blue  [%.0f]" (gStreetDMX_GR1_b){ channel="modbus:data:beckhoff:DMXstreetlamps1_123:fix1b:dimmer" }

Three dimmers: R, G, B

On your phisical device 4 channels?
How to manage color through color channel if I have 3 dimmers?
Through rules?

Didn’t we already go through this for your KNX RGB device?

1 Like

Does this mean that we can’t do this without rules?

Depends what you mean by “this”.

But nothing has changed in openHAB since last time. Color is held internally in openHAB as HSB, if you want to convert to three separate RGB values then you have to do work.

I mean, maybe in this binding the color itself translates the values to 3 dimmers and back

You’re talking about the Modbus binding now?
No, there is no way to do that.

You could write three different transformation scripts to select the R or G or B parts of a Color type Item. Then link one Item to three different Modbus data Things targeting different registers, each Thing using a different write transform script.

But it would be a bit pointless, because there is no way to combine incoming data from three different Modbus data Things without using rules.

Are you paying a lot for rules, what is the objection here?

The DMX binding does convert the Color channel into the 3 individual channels

No, not modbus binding.
DMX binding.
Yes. I paying a lot for rules.
82 fixtures for 3 channels (RGB).
My powerfull server (24 cores) without rules hard to cope with managing a group of 82*3=246 items.
(Items to modbus tcp)

Okay. The Items you asked about use the Modbus binding, not DMX binding. Try to provide examples related to your questions.

People run openHAB on Raspberry Pi, you probably ought to look into why your system performs so poorly.
You mention a fair sized Modbus configuration, which certainly can make an impact on performance if you do not take care.

In case anyone wants to do this with Velbus, I have an RGBW ledstrip, with a VMB4RYNO, a VMB4DC and 2 VMB2LEDDC
And managed to make this work thanks to @rossko57 and @Bagunda