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Randytenn

DMX RGB Dumb Lights Flicker/Flash

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Randytenn    7

We've been using RGB Dumb strips and pixels for 5 years.  Just this year, we started experiencing a noticeable amount of flashing/flickering.  Here is what I'm seeing.

During the show, we see the flashing very badly.  So, to test, I turned all 21 channels of RGB Dumb strips on red.  They all, at the same time, flashed the blue channel for an instant.  They all do it at the same time, despite being on separate controllers and separate power supplies.  They are split between two LOR boxes.  

If I turn them all on to Blue, I see a green flash, and if I turn them on to green, I see a red flash.  White, and of course, no flashing/flicker.  It is possible they flashed all the channels at once, but that is what I could see in that instant.   

We've switched dongles/ports on the computer.  We've switched computers.  We've unplugged one side, unplugged the other.  We've used brand new lights, and old lights.  

Tonight, we built a new LOR configuration file, with just two strips, and they still flashed, but at a slower rate, to start.  

So, in my mind, I'm not sure what else we can eliminate.  Anyone have anything else we can look at?
 

Thanks

Randy

www.lakenonalights.com

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George Simmons    1,154

My first thought is that there must be something corrupt with the sequence.  That would explain it happening on all channels.  Are you certain all your RGB channels are configured correctly in the sequence?

You mentioned a new config, but no mention of whether it happens with any/all sequences or just one?  Is it always at the same point in time during the sequence?

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Randytenn    7

Hi George,

It's sequence agnostic.  Happens on all of them.  Even happened last night when we built a new sequence of just turning all the lights on red for 10 seconds.  Then, just to make sure there wasn't something wrong with our configuration file, we built a new one from scratch with just two of the channels, and it happened again.

It does not happen at the same time in a sequence.  It's almost as though the software is sending random signal to all of the controllers at the same time.  

In my mind, we've eliminated everything from the lights, all the way back to the dongle as the source, based on the fact that we have two LOR boxes sending signal to the DMX controllers, and we are seeing the flashing uniformly across all of the channels.  We've tested multiple dongles, multiples ports on the computers, and multiple computers.  

It's a real head scratcher.

--Randy

www.lakenonalights.com

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Mr. P    299

Make sure your cat5 cables and power cables are completely separated, at least 18 inches.

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plasmadrive    318

Here's are 2 thoughts.

1.  If the feeder cable goes to the first controller and from there a second cable goes to the next controller, you may be losing signal integrity at the input of the first controller.  Try this,  Run a new cable straight to the second controller from your signal source, be it a computer or whatever.  I that fails to show the problem you have narrowed it down to either the cable, connector on the first controller, or the first controller itself. 

2.  Do you have a terminating resistor at the last controller? (100-120ohm 1/4 watt is fine).  You could be getting random reflections on the data line.  You could have run fine for years and just a different cable route or length or moisture can cause that situation.

The more I think about it, the more I think it could be the #2 idea

 

Edited by plasmadrive

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Randytenn    7

We come from the dongle to a splitter, and out to the controllers.  We've tried unplugging one side, and it persists.

We've tried a terminating resistor, but It didn't work either.

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plasmadrive    318

A splitter?  You should have no splitters.. they should be daisy chained..  if you tried unplugging one side, I assume you mean one side at a time?  Does it still happen on the side that is plugged in?
did you try a terminating resistor at the one that was left plugged in?  It has to be right at the controller where the DMX ends..

Edited by plasmadrive

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Randytenn    7

The house is divided in two, so we use the splitter to send the signal to the halves.  From there, the controllers are daisy chained in their halves. 

Yes, when we unplugged one side from the splitter, the issue remained.  

Also when we set up the new test configuration, we only used two single controllers on one side, and the flashing occurred. 

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Randytenn    7

One thought... The dongle forced the first dmx channel to be channel 2, instead of 1. It's been this way for five years, but just wondering if something might have creeped up there. 

 

So, the first controller is channels 2,3,4 .  The second is 5,6,7.  Etc.  The fact that we seem to be getting a flash from one channel up interests me, but it might be nothing. 

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plasmadrive    318

what dongle are you using and what splitter are you using and do you have terminators at the end of each line?   Are you using IDMX units?

 

Does it happen when the lines are unplugged from the splitter just hanging in mid air?  If not, does it happen when they are plugged into the splitter but not into the computer? 

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Randytenn    7

Issue resolved.  (Hopefully!)

We took it back to basics, and built a workbench system.  Computer, dongle, controller, power supply, strips.  No flashing.  When we added a 2nd controller with power supply and strips, they started flashing.  So, we ruled out anything on the house.  We knew it wasn't the strips, because they worked by themselves just fine.  Each had it's own power supply, so no issue there.  

So, that left the computer, software and dongle.  We luckily had several computers, with several versions of LOR.  Hooked them up, and each flashed.

That left the dongle.  We had two, and they both flashed, but they were similar style, so we called a friend who has a very large display, and he had a couple different type dongles he wasn't using.  A quick drive over to grab them, we hooked one up, and voila.  No flashing.  

So, something happened between last year and this year with that style of dongle and Windows, or LOR, or something.  

Thanks everyone for the comments and advice.  Keep your fingers crossed that this holds up all season!

--Randy

www.lakenonalights.com

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