Conventional Fixtures DLED Elation RGB 108 PARS: ghost in the machine

[Margaret]

View attachment EPSON001.PDFHey all!

First post for me so let me know if I'm doing anything wrong.

I have 73 ELAR PAR 108s in the show I'm working on. We have them split between two universes I attached a circuit map of how the DMX is run.

The problem that we are having is that if they are all on and we turn them all off at the same time some of them don't turn off and are stuck in the white circuit stay on until they get another command other than out. Its never the same fixture that does it. We terminated two of the three tower and it didn't seem to make a difference. (see picture)

When we run them in an effect they also do a slight shutter and or flicker. The flicker is comsistent but the lights that do them are not.

Any thoughts?

thanks so much
Margaret Hartmann

 

[DuckJordan]

My guess is there is signal degradation I've heard that the max fixtures you should run in a chain is about 30.

sent from my Droid incredible using tapatalk.

 

[sk8rsdad]

DuckJordan is likely right. Add a DMX splitter to get the number of fixtures per branch below 32; lower than 30 would be safer.

If that doesn't fix it, there's a possibility of cold solder joints in DMX connectors in the fixtures. I've encountered it on other mass-produced LED gear.

 

[Margaret]

Hello!

Thanks for the quick reply. The largest number of fixtures I have in a chain is 28.

The longest chain goes like this (not in order). I've attached a file to the post that
shows the data runs.

24 DLED's
3 MAC 350 Entours
1 Colorblaze 72

so, less than 20 fixtures.
I'm not sure how to react to the cold solder joint comment. What kind of
fixtures are we talking about? These are from Elation which is a relatively
high end company. They seem like really well made instruments ie: not your
average DJ light.

Any more suggestions?

thanks again,

Margaret

 

[xander]

These are from Elation which is a relatively
high end company. They seem like really well made instruments ie: not your
average DJ light.

First of all, Elation most certainly is not a high end company. They are in fact a DJ company. I will admit they are better than they used to be, but I would categorize them as lower mid range quality wise. With that many units, I wouldn't be the least bit surprised if you have some sort of product defect in one or a few.

Besides that, though, I still think that it is a signal issue. While the DMX standard states the maximum device count is 32, what is considered one "device" isn't exactly intuitive. Since your counts are getting close to the maximum, my first step would be to add another line. Most likely these fixtures do not have highly sensitive receivers and if you don't have a signal booster inline, the data is probably not getting across unadulterated. I would add another opto and split the two particularly large runs into two separate runs each. And TERMINATE EVERY RUN!

-Tim

 

[Margaret]

We have now isolated the runs to 12 DLED pars each run and terminated each of those.

Still getting the random flicker issue, they are also staying on when we don't want them to.

I'm planning on calling Elation on Monday but if anyone else has any thoughts, I will take them readily.

best
margaret

 

[sk8rsdad]

I see from the website that they have a master/slave audio mode. Is there any chance it's kicking in on loss of DMX signal?

Is there any pattern at all to the ones that are flickering or staying on? It might help isolate the reason.

 

[xander]

Huh. What kind of control are you using? What kind of opto? Any chances that there is some sub-par cable (e.g. mic cable) in the mix? Are the problem fixtures always in the same universe? Same opto output?

-Tim

 

[DuckJordan]

Since it is three pin DMX i would bet that with how you stated you though that elation was a higher end company. I can almost certainly bet that your running mic cable for those 3 pin runs. THIS IS A BIG NO NO. Specially on runs of that distance and fixture count. Yeah it will sometimes work but this is the best example of why to not use Microphone cable to do a DMX job, Microphone cable has too many impurities giving it a fairly random impedance along the cable line. DMX on the other hand is manufactured to stay as close as possible to 120.
I second that every run should be terminated without terminators you will get signal bounce and likely un-intended results.

 

[Margaret]

The PARS are actually 5 pin and the cable is all rental and not mic cable. Sorry I thought Elation was higher end I take it all back.

I have simplified the runs and terminated them and am still having the same problem.

thanks
margaret

 

[Margaret]

The control map goes

EOS
ethernet
ethernet switch
ethernet
NET3 Gateway(4 port) Universe 4
5 pin DMX
Opto Isolator
5 pin DMX
fixture

- problem fixtures are in universe 4 and universe 6.

- Both universes have the same control. 4 has an opto, six does not.

- Problem fixtures are inconsistent.

- There might be some sub par cable but it would mean there was at least 4 sub par cables because each tower has a different run from the NET3 Gateway box.

Also, I should mention that we changed the NET3 IP address to static already.

I guess I'll start replacing cable one by one....

thanks
m

 

[mstaylor]

Try isolating the dissimilar fixtures. Sometimes mixing different types of fixtures can create problems. Being you are having LED problems, try just a chain of those and see if the problem persists.

 

[xander]

It is only the Elation 108s that ever malfunction? All other types of devices on the same lines always work 100%?

 

[Margaret]

So far its only the Elations that are malfunctioning. Tonight was the first full night of programming - we don't start full tech till tuesday so there's still time to find out that other things are having problems. I have one opto iso splitter left and a host of DMX so I'm probably going to try to isolate the ones in universe 6 - split them in to 6 runs of 6 each and terminate each of them.

maybe the ghost will rear its ugly head.

On a side note, the designer I'm working with says that he's strung like 500 of these together and never had this problem, which makes me feel like we're barking up the wrong tree....

thanks again
m

 

[mstaylor]

So far its only the Elations that are malfunctioning. Tonight was the first full night of programming - we don't start full tech till tuesday so there's still time to find out that other things are having problems. I have one opto iso splitter left and a host of DMX so I'm probably going to try to isolate the ones in universe 6 - split them in to 6 runs of 6 each and terminate each of them.

maybe the ghost will rear its ugly head.

On a side note, the designer I'm working with says that he's strung like 500 of these together and never had this problem, which makes me feel like we're barking up the wrong tree....

thanks again
m

Tell the designer that DMX works until it doesn't. You can do many things with DMX that isn't exactly kosher and get away with it until you don't. I suspect one of two things, the dissimilar fixtures fighting or it may be a DMX rate problem. If you can change the rate so it is faster or slower than it is now, that may fix the problem. I know there were some instruments that had a problem with this, not sure about these particular Elation products.

 

[derekleffew]

... or it may be a DMX rate problem. If you can change the rate so it is faster or slower than it is now, that may fix the problem. I know there were some instruments that had a problem with this, not sure about these particular Elation products.

I second it being a rate issue. What sounds like similar symptoms, albeit with different fixtures:

The random flashing you are describing is due to the low quality DMX transciever chip with the Colorstrip not being able to take 44 times a second refresh rate on the DMX. As I understand it the buffer fills up and just kinda freaks out.

However, there is hope - If there is a way to slow your DMX speed down coming out of the console, I would try that.

I had this same issue with these exact fixtures a year or so ago with an ION console. I was able to slow the DMX speed down and there was no further issues. I was not able to slow it down enough on the Expression console to get it to work though - Just the ION. ...

jmabray got it right. SHARYNF's explaination of the problem is also accurate. Because of the interbyte timing needed by the fixture, they do not meet appropriate timing guidelines.

Here is information about DMX Speeds and timing that is implemented on ETC Products from our Wiki Article:

We, ETC, adjusted the timing speed of our "slow" setting to compensate and allow for the extra timing required by the Chauvet fixture. (They required a 46μs interbyte time)

We also discussed with them about how to change their fixture to meet spec, but they declined to take action. ...

I can confirm that the issue is resolved. As was done the first time this issue showed up on Jim Mabray's customer site, Chauvet sent some sample fixtures to ETC and ETC sent an Ion to Chauvet. We both did testing and verified that the updated design worked fine.

At ETC, we tested the fixture by using a very wide variety of timings [all within the DMX spec] by altering Interbyte, Interpacket, Break, MAB, and Post Start lengths. We were not able to recreate the same failures found in the earlier fixtures. Chauvet even sent us one of the old ones to reconfirm all findings. ...

-----

...They seem like really well made instruments ie: not your average DJ light.

Indeed, MSRP on these is $1200, so hopefully in a different class than the typical LED PAR.

 

[len]

The PARS are actually 5 pin and the cable is all rental
thanks
margaret

I'd check with the rental company, first. If they rented you all those fixtures, and data, etc., for a length of time, the rental is likely pretty big $$. They have an incentive to keep you happy for the future. Also, there may be some hidden setting in the fixtures (Elation is notorious for this) causing a problem.

 

[Margaret]

I'd check with the rental company, first. If they rented you all those fixtures, and data, etc., for a length of time, the rental is likely pretty big $$. They have an incentive to keep you happy for the future. Also, there may be some hidden setting in the fixtures (Elation is notorious for this) causing a problem.

Unfortunately we are renting from a company in new york who is cutting us a huge deal in exchange for right of first refusal when the show goes to broadway.

So.. We are unsupported by the rental house. I am emailing them now though.
Thanks for your thoughts!

Also, we went into the menu and changed a couple of hidden settings but to no avail.

keep the theories coming! I appreciate them!


Margaret

 

[Margaret]

We are working on slowing the dmx setting right now. I was talking to the designer and he was saying that the last time he used these fixtures there was a wall of almost 500 of them. He was running them off an EOS in the same kind of scenario and had none of these problems.

thanks again for all of your help
margaret

 

[mstaylor]

What board are you using?