Invert Pan/Tilt Fine LSB Channel


I’m using a handful of cheap RGBW Wash Moving Heads (7x12W Beam) from china. They work actually quite great, but they present an issue: the Pan/Tilt fine channels (LSB) are inverted (and move in the opposite direction than the Coarse channels).

This causes extremely jittery (sawtooth-like) movement of the heads when using 16-bit control, especially on slow movements.

This could be very easily fixed by implementing an “Invert channel” toggle, as discussed, but since this is for sure a weird issue, are there any xml attributes I can use to achieve this by editing the .Fixture? Either in the channel tag <Channel offset="13" ID="Pan Fine"/> or the Head tree <Parameter name="angle" resolution="16"><Protocol IDREF="Pan" shiftLeft="8"/><Protocol IDREF="Pan Fine" shiftLeft="0"/>.

I’m attaching my fixture profile so it can be analyzed by whoever wants. rgonBEAM 7x12 LEDv2.Fixture (1.3 KB) It appears to be the same as the OEM > LED Wash RGBW MK2 in the Fixture library, which has the same issue.

The issue has been noticed before by another user way back with M-Touch: thread 2224, so it must be present in a few chinese lights.

I’m reopening this topic in the (non-archived) Onyx category, as the issue is still present.

Thanks for your attention,

Sure: the “Channel” element supports an attribute “invertChannel”, which accepts values “yes” and “no”

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That fixed it! The head moves like it’s a different machine now!

If anyone finds themselves in a similar situation, apparently changes in the invertChannel attribute can’t be seen just by updating the profile in the library and doing a swap (same fixture name and type). I’ve got no clue as to why, but it has costed me quite some time. To see the changes, you need to:

  1. Swap offending fixture with another one of a similar type but different name.
  2. Save and close the show file.
  3. Import the new profile using the Library Manager.
  4. Re-open the Onyx showfile and swap the intermediate fixtures with your fixed profile.

Here’s the fixed fixture file (if anyone finds this in the future and needs it): rgonBEAM 7x12 LEDv3.Fixture (1.6 KB)

I’ve also had some trouble: Onyx didn’t recognize my repackaged .Fixture (.zip) files. So here I share with you a small Go program I’ve written that compresses the fixture file with a format that Onyx recognizes (proper fs type, attributes etc analyzed with zipinfo). Here’s the code and brief instructions on how to use it: if anyone has the same problem. It works just fine on my main Linux machine, should work on Windows as well. Beware that there might be easier solutions to this.

Hope it’s useful to the rest.
Thanks for your help, Gert!

Should have mentioned: if you modify an existing library, you need to increment the libraryBuild in the root element (library editor does that automatically) and then restart the software (using Continue with current show), then the changes are applied while loading.