Control/Dimming Cyc Lights Flickering

Alex Snyder

New Member
We've recently switched over from an old Horizon Marquee system to qlab to handle our lighting needs. I'm running through an ArtNet controller to 5 pin DMX to a wall panel that handles the dimming (not sure on brand or anything else about it) All of the lights use the 3 pin stage plugs. The only thing that isn't working is the cyc lights. They're our highest addressed lights but I'm not sure if that makes a difference. They worked fine when using the old console. After I switched to the artnet interface they started to flicker, however, when I switched back to the console they would work fine. Now they flicker between both systems. There are 14 addresses assigned to our cyc dimmers. They are using convention bulbs, not LED. We have a performance in a few days so any help would be nice.
 
Sounds like a data bottleneck or frame rate problem. Since it is showing up on conventional lights, the problem is probably a lot worse than it seems. If you have an LED fixture handy, program it to that address and patch it in the cyc light chain. My bet is there is a heavy pattern of dropouts that only show when they are clustered. Then, drop the fixture to a lower address and see if those channels have some disturbance as well. Once you can confirm the channel spread, the next step would be to lower the frame rate speed on the board and see if that helps. Something is choking.
 
Sounds like a data bottleneck or frame rate problem. Since it is showing up on conventional lights, the problem is probably a lot worse than it seems. If you have an LED fixture handy, program it to that address and patch it in the cyc light chain. My bet is there is a heavy pattern of dropouts that only show when they are clustered. Then, drop the fixture to a lower address and see if those channels have some disturbance as well. Once you can confirm the channel spread, the next step would be to lower the frame rate speed on the board and see if that helps. Something is choking.
Thanks for the reply. The flickering went away after about 30 minutes and stayed away the rest of the rehearsal. I'm wondering if the dimmer was just freaking out from switching between the lighting console and the artnet interface.
 
The most important bit here is the "both systems" part. Im leaning towards high voltage side other than low voltage side issues.
What was the flicker like? Only on intensity moves? Or constantly?
Is the DMX run terminated at the end of the chain or in a self terminating unit?
Was it a regular rate, or random?
How is your cyc circuited?

Personally I would have checked the dimmer output side if were in a single dimmer rack (ie, Sensor rack with one DMX processor) for something loose. Circuit details would def help flush it out though. (Dimmer > Mult > Breakout> fixtures?) If it looks something like this, just start at the lights and unplug and replug everything. If they havent been touched in awhile, check the connectors themselves. Loose conductors? Loose plugs? Dirty or burned out contacts? And while your there dust them!

If this does end up being the issue, I would count on it appearing somewhere else at some point. Take a quick look around for any other potential trouble makers.

Just remember, a problem with out a determined source is a still a problem taking coffee.
 
I know very little about lighting systems as I'm an audio guy, but I know enough to get by, so I apologize in advance if this is vague. There is one DMX run that goes to a wall panel back stage. Everything about the box is tightly sealed but it's obviously the dimmers themselves. This breaks out to some probably 3 inch conduit that must break somewhere above stage and split to the cyclorama bar, two more bars above the stage, a group of catwalk lights slightly in front of the stage to light it from the front, and sections of house lights, 2 sets of courtesy lights, and some wall lights. I don't really have a good way to describe the box. I'm assuming it's just dmx decoders inside controlling lighting voltage. All of our lights use stage pin connectors to my knowledge. The system was installed professionally and brand new in 2007 so I would like to think it was properly terminated since it hasn't had any issues before. As far as the connectors go nothing seemed loose when I looked yesterday. everything had a nice tight fit and all was shiny. No dust. The flicker rate of the lights was almost a pulsing effect with all of the cyc lights pulsing at the same time. Sometimes they would speed up or slow down, but the light level didn't make any changes.

Rehearsal went smoothly today without flicker. The only issues were actors muting their transmitters on accident, typical.:clap::lol:
 
Gotta ask why did you not stick with the Marquee system.

Was it just to intergeate QLab as the main show control?

Personally if that was the only reason I would MIDI trigger out of QLab to the original console.

If not then it could be a transmission issue but the only way to test it would be to try and recreate th problem and document it well. It’s hard for us to do much pass what’s been said.

Pictures/video help a lot with this.
 
I wanted one system to be able to control a majority of the show. I could have just run midi, yes. But there is no support for the Marquee and trying to find any replacement parts has been a pain (a good chunk of the controller doesn't work so we do it all in the software anyway). While I went to school for Audio Engineering my actual job is an IT coordinator for this school district so all repairs go through me. (This is the marquee website if you want to call it that http://www.horizoncontrol.com/html/marquee.html). The way I have things setup now is an m32 sending midi over USB to a trashcan Mac Pro so I can control anything I need to while at the M32. Sound effects, show changes etc. Along with this Qlab is a lot faster to program the lights, believe it or not. I'd like to venture into moving heads in the future and I'm not sure how well the marquee would support that being that it's ancient and has no support. I'll try to snap pictures of the setup today before or after the performance.
 
Pathway has a good presences on here. Do a search and send some PMs the names are alluding me this morning. I am sure they could get your board operational again.

As far as setup I’m sure it’s all proper it’s really a matter of trying to recreate the issue again and hoping your camera is handy when it does.
 

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