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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Lighting Forum => Topic started by: Gordon Brinton on November 11, 2018, 08:02:22 pm

Title: DJ Scan 250, erratic behavior with new controller.
Post by: Gordon Brinton on November 11, 2018, 08:02:22 pm
I recently dug out some old American DJ, DJ Scan 250 mirror scanners to play around with. I'd never used them with my newer DMX King controller before and wanted to try it out. They seem to be plagued with erratic behavior very frequently. When turned on, but not moving, they just do random glitchy movements and color changes every few seconds without the controller telling them to do so. Otherwise, they work well and respond to all DMX programming.

Iíve tried changing the cabling, (I use only designated DMX/Data cables,) Iíve isolated single fixtures from one another, terminated the last fixture, reduced/disabled sound sensitivity, and tweaked every setting in the controller imaginable. Nothing seemed to help.

Finally, I dug out an old Elation hardware controller and hooked it up. Suddenly, the erratic behavior is gone. They sat turned-on for over an hour with no glitchy movements at all.

What gives here? Is there something proprietary about older American DJ lights that makes them work with Elation, but not other brands of controller?
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Jeff Lelko on November 11, 2018, 08:31:29 pm
What gives here? Is there something proprietary about older American DJ lights that makes them work with Elation, but not other brands of controller?

Hi Gordon, not that I'm aware of, and I say that as a owner/user of many ADJ vintage effects.  Some manufacturers such as Martin would do things like swap pins 2 and 3 on units such as the Roboscan 812s to maintain compatibility with older proprietary controllers, but I'm not aware of anything similar being done by Elation/ADJ. 

Is there a way to adjust (lower) the DMX speed on your controller?  The speed at which a controller transmits DMX isn't proprietary, but sometimes if a unit can't "keep up" with the signal its being sent you can start getting framing errors and thus erratic behavior.  This is where I'd first look, and would be a provable explanation of why your lights would work with one controller but not another.  Good luck and hope this helps!
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Bob Stone on November 11, 2018, 11:08:10 pm
Silly questions but worth asking...

Sure they're on the right channels?
Sure there aren't recorded cues that are being output?
Sure there isn't something else broadcasting dmx on the universe?
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Jano Svitok on November 12, 2018, 01:28:08 am
Since DMX King devices are computer based, what software do you use? What exact model is DMX King and Elation?

Does it help if you force dmx king to output full universe (e.g by raising channel above all used channels)?
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Gordon Brinton on November 12, 2018, 05:04:38 am
Hi Gordon, not that I'm aware of, and I say that as a owner/user of many ADJ vintage effects.  Some manufacturers such as Martin would do things like swap pins 2 and 3 on units such as the Roboscan 812s to maintain compatibility with older proprietary controllers, but I'm not aware of anything similar being done by Elation/ADJ. 

Is there a way to adjust (lower) the DMX speed on your controller?  The speed at which a controller transmits DMX isn't proprietary, but sometimes if a unit can't "keep up" with the signal its being sent you can start getting framing errors and thus erratic behavior.  This is where I'd first look, and would be a provable explanation of why your lights would work with one controller but not another.  Good luck and hope this helps!

Swapping the pin-out is about the only thing that I have NOT yet tried. I may have time to do that after work today or tomorrow. Thanks for the idea.

As far as refresh speed/update rate, yes, I've already tried that. Mine is adjustable from 1 to 40 times per second.
Between 10 and 40 = no change.
Between 1 and 10 = The time between glitching slows down, but does not go away.
(The time between glitches seems to also be random and sporadic, anywhere from 1 second up to 5 or 6 seconds.)
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Gordon Brinton on November 12, 2018, 05:12:18 am
Silly questions but worth asking...

Sure they're on the right channels?
Sure there aren't recorded cues that are being output?
Sure there isn't something else broadcasting dmx on the universe?

Yes, these have the old dip switches and during my experimenting I have been switching them to many different start channels. I am well experienced at understanding and setting DMX channels.

No recorded cues or sequences going on. I use Luminair 3 and simply created a whole new "blank" project to experiment within. I only added the correct number of channels for theses fixtures and nothing more.

I had also tried sending DMX both hardwired and through the wireless sticks. Same result either way.
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Gordon Brinton on November 12, 2018, 05:23:23 am
Since DMX King devices are computer based, what software do you use? What exact model is DMX King and Elation?

Does it help if you force dmx king to output full universe (e.g by raising channel above all used channels)?

I am using Luminair 3 on an iPad. My wifi is private and not connected to the Internet. All other devices such as mixer, phones, tablets have been eliminated.

My new controller is eDMX1 Pro, single universe. https://dmxking.com/downloads/eDMX1%20PRO%20User%20Manual%20(EN).pdf (https://dmxking.com/downloads/eDMX1%20PRO%20User%20Manual%20(EN).pdf) It has been updated with firmware v3.0. I've been using it for about a year now and it works perfectly with all of my other fixtures. I forget what model the old Elation is, maybe Operator 192 or something like that. I'll check after work.

I've set the output bandwidth to both ways; Broadcast, (all IPs,) and Unicast, (single IP,). Same result either way. Still random glitching. There are no other fixtures on the universe.
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Jeff Lelko on November 12, 2018, 11:15:19 am
Swapping the pin-out is about the only thing that I have NOT yet tried. I may have time to do that after work today or tomorrow. Thanks for the idea.

I donít know if would do that.  I was just giving some context to something Martin did on their late 90s fixtures, but I donít believe the DJ Scans fall into the same bucket.  While you wonít hurt anything by trying it, if that solves the problem I think youíll have larger issues that need to be addressed. 

Have you tried playing with the other settings on your unit besides the DMX speed?  The fact that you at least get a result when lowering the speed (despite not solving the problem completely) would imply that something isnít 100% agreeing with the DJ Scan in the signal youíre broadcasting.  Have you disabled RDM? 
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Paul G. OBrien on November 12, 2018, 01:03:40 pm
I recently dug out some old American DJ, DJ Scan 250 mirror scanners to play around with. I'd never used them with my newer DMX King controller before and wanted to try it out. They seem to be plagued with erratic behavior very frequently. When turned on, but not moving, they just do random glitchy movements and color changes every few seconds without the controller telling them to do so. Otherwise, they work well and respond to all DMX programming.

I have seen this problem too on occasion and I think it is either a cable problem or a noisy AC problem. Two things I have found that "fix" the issue at gig setup where there is a limited amount of time to troubleshoot is either put the hardwired signal through an opto isolator/splitter or put each fixture on it's own wireless receiver thus eliminating the cable link between them. It is hard to track down the cause of this as the same fixtures work fine linked together some of the time but other times have to be separated.
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: duane massey on November 13, 2018, 12:35:01 am
I had this problem back when these fixtures were still in production. Worked fine with a Showdesigner, any other controller and we would get random glitches and twitches. Had similar problems with the DJ Spot. Fortunately the two venues lasted about as long as the fixtures.
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Gordon Brinton on November 13, 2018, 04:56:19 am
I tried reversing pins 2 & 3 on the dmx cable. The light went completely berserk and was uncontrollable. I had previously also tried switching out cables, both dmx/data and mic, using wireless sticks, isolating each fixture, and using two different terminators. I think I can safely rule out cabling as the cause...
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Jeff Lelko on November 13, 2018, 08:06:47 pm
Swapping the pin-out is about the only thing that I have NOT yet tried. I may have time to do that after work today or tomorrow.
I donít know if would do that. 
I tried reversing pins 2 & 3 on the dmx cable. The light went completely berserk and was uncontrollable.

I told you not to try that!  Not that it'll hurt anything, but that's along the lines of what will happen.  The pins 2 and 3 reversing was a Martin thing in the late 90s. 

Have you tried playing with any of the settings on your interface besides the DMX Speed? 
Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Scott Holtzman on November 14, 2018, 12:39:42 am
I told you not to try that!  Not that it'll hurt anything, but that's along the lines of what will happen.  The pins 2 and 3 reversing was a Martin thing in the late 90s. 

Have you tried playing with any of the settings on your interface besides the DMX Speed?

When I first read this I wondered if you are using an immediate transition or a stepped?

Title: Re: DJ Scan 250, erratic behavior with new controller.
Post by: Gordon Brinton on November 14, 2018, 02:32:31 am
I told you not to try that!  Not that it'll hurt anything, but that's along the lines of what will happen.  The pins 2 and 3 reversing was a Martin thing in the late 90s.
 

Others told me to try it...that it wouldn't hurt anything. I only did it with one fixture that is not a part of my normal stage show. I like to use the Process-of-Elimination when problem solving. Now I know.

Have you tried playing with any of the settings on your interface besides the DMX Speed?

Oh, yes. I'd spent a few hours tweaking almost every setting in the thing. DMX speed was the only setting that got a result. Albeit, not a satisfactory result.