The Lighting Controller

Ok, so my Artnet light controller I'm developing has 1..4 channels configurable.

If a user has a device configured with 4 channels, but only wants to set values for channels 1..3, an extra 0 for channel 4 is automatically added (artnet doesn't support uneven lengths).

So the challenge is, how do I know if they want 4 to be set to zero, or if they simply haven't set it.

Any best practice around this?

You are asking this on the forum of a software light controller developer?

And to answer your question, if a user only want to use 3 channels, then the user changes that on the fixture, and thus only uses 3 channels on the controller thus forcing the user to use another preset for that fixture on the controller.

Yes, I'm a firmware developer developing a light controller.

Your answer precludes the possibility of there being 4 valid channels on the controller, but the user wishes only to set values for 1..3. In this case, 4 will be forced to zero regardless of its current setting.