Kulp K16A-B RJ45 differential receiver output pixel count specs?

[aggieNick02]

I have a Kulp K16A-B v1, and added more pixels to my SRx4v4 receiver boxes this year. I'm seeing very intermittent flickering and am guessing I am over a port pixel limit, but can't find what that limit is in the K16A-B specs.

The F8-B spec (https://kulplights.com/manuals/F8-B-Manual.pdf) lists 640 per port, but I am guessing this is 700-60=640 for v1.x smart receivers. The K16A-B spec (https://kulplights.com/manuals/K16A-B-Manual.pdf) doesn't list a limit.

The problematic SRx4v4 config is 655, 604, 650, and 400 pixels on the 4 ports spread across the A,B,C,D receivers. The problem persists if I swap ethernet cable and SRx4v4 box (so the output from the RJ45 is problematic, not anything downstream). The problem persists in FPP display testing mode.

My best guess was that my limit should be 700-11=689 pixels per port (https://www.wiredwatts.com/falexprec16v1). The flickering I am seeing is similar (but not nearly as bad) as the flickering I saw when I accidentally went over the 689 limit. It is the first 4 pixels on port 2A and the first 50 or so pixels on port 1B, and happens on the order of once every 30-60 seconds.

It is pretty hard to catch on video (much more noticeable with eyes), but you can see it on 4 lights in the center around time 27 seconds here:

[jnealand]

Just my personal opinion, but that is way more pixels to have on one receiver than I would ever consider.  But then I like to keep my lights in smaller batches except when there is no other way to do it.  I look it from the lens of "if the device fails how much of my show do I lose".  YMMV and there are lots of ways to do things which is a benefit to all of us.

[tetleytealeaf]

Did you confirm you don't have a power issue?   For example run just 50 pixels on all 4 ports of receivers A,B,C,D and those 50 pixels still flicker?

The thing is, you said your flickering was intermittent.  If you had configured the smarts wrong, the flickering would be always; not intermittent.

[aggieNick02]

Thanks @jnealand for the feedback on breaking things up, and @tetleytealeaf for the debugging ideas. Sorry for the delayed response (just fixed it so I get email notifications now).

I'm pretty certain it isn't a power issue. I can swap RJ45 outputs so that the problematic RJ45 port on the Kulp is connected to a different ethernet cable and smart receiver, and the different smart receiver is on a different electrical circuit, and the problem reproduces there. I will try disconnecting pixel outputs soon to make sure it still reproduces with minimal power load though.

The reason I think it might be configuration is because I previously accidentally went over the 700 per port limit, and had very similar behavior. It was way more frequent but still not deterministic, which really surprised me. I'd be much happier if all of the lights would just not function if I was over a limit. ;-)

The flickering seems to be getting more frequent. I actually think the most likely issue is some part of the Kulp hardware failing. The trees it happens on are off to the side so it isn't super noticeable for the show, so I may look at a Kulp board upgrade for next year to both add capability and rule the current board in or out as a cause.