Best practice: RGB non-addressable DMX fixtures

eDMX and Art-Net
1

Hi Mitja and all,

I am setting up an exhibition with a mix of RGBW (addressable), RGB (non-addressable) and white (non-addressable) LED strips, all controlled from LightAct. I am trying to figure out how to design the eDMX fixtures for the non-addressable RGB LED strips.

Since all the pixels on the strip will be the same color and brightness, I want to control the color of an entire RGB strip with only 3 DMX channels.

What is the best practice for making an eDMX fixture for non-addressable RGB lights?

Thanks!

2

Hi,

Well essentially, from LightAct’s perspective, the entire strip is just one RGB (or white) pixel.

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Here, for example, is a 1 RGB pixel LED strip, 100cm long and 2 cm high.

3

Hi Mitja,

Thank you – that’s helpful. And just to double check, the geometry of the fixture in cm does not affect the DMX output, correct? If I make a fixture that is 1x RGB pixel, it does not matter if it’s a 100 cm x 2 xm or 1 cm x 1 cm or 200 cm x 200 cm, as long as it is placed correctly to receive color information from the thrower / video screen. Is that right?

Thanks,
Scott

4

That should be the case, yes.

Best,
Mitja

5

Great – thanks.

So, in testing this, I have made a 1 px RGB fixture, which in the Fixture Editor says it will occupy 3 channels. In the DMX output, however, I only see one channel occupied. Why is this? Shouldn’t it be 3 channels?

Thanks,
Scott

210810_RGB_channels
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6

Hi,

There is something strange in your screenshot indeed. In the properties of your 1x1 fixture it says that the end channel is 3/2 whereas it should say 3/4 for a 1 pixel RGB fixture. Please find here a 1x1 xml fixture I used for testing which appears to work fine.

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A screenshot from my test.

Maybe copy this xml file into C:\ProgramData\Lightact\Lightact3\fixtures and try it out.

Let me know how it goes. If it doesn’t work, please send over the xml file of your 1x1 fixture so we can check it.

Thanks,
Mitja

7

Hi Mitja,

Your 1x1 fixture worked correctly, and, after rechecking my 1x1 fixture, it now seems to be working correctly. I’m not sure what changed – I’ve closed and opened the file several times since I saw the original issue. Here is the XML file for my fixture just in case there’s something strange about it.

Thanks!
Scott

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