DMX In sACN Start Code usage

I’ve got a little sACN viewing widget that I’ve made, but I’m running into an issue.
All channels will flash at the level of the channels priority intermittently. I’m guessing this is because TDs implementation is not taking into account per-channel priority, and it’s reading that data as level data by mistake.
I think I can fix this by having TD ignore all packets with the per-channel priority start code, but I’m already at the boundaries of my knowledge, so I’m not 100% sure what to put in to the ‘start code’ field. It looks like the start code for the per-channel priority packets is 0xDD, but other than that I’m at a loss…

Anyone had similar issue/found a solution?

OK, in case anyone comes by here; just solved the problem (I hope!). Put a 0 in the start codes field. This should filter out everything except the level information. Of course if you need other info, you’ll have to find the start code for that and add that to your list.

Sounds like you’re using an ETC console. :slight_smile:

They are the only ones who even send that packet, and not even their own dimmers or fixtures on the other end of the line even pay attention to said packets soooo…

There are other places where this same problem happens (every channel flashes at 39%) but it’s usually cheaper hardware that doesn’t have a fancy “start codes” field that can be used to filter out those packets.

Actually I can’t think of any other place where any start code other than 0 is used, AKA pretty much everything only uses sACN to send / receive levels, so I’ve never had to think about start codes until that per-channel priority bug. I wish there was some way to disable that on the Eos / Ion stuff.