Control/Dimming Flakey DMX Issues

[jmac]

Having DMX issues.. Running a one-year old ETC Element, which I do not suspect is the issue. (Except maybe there is a DMX speed issue..?)

We run two universes out of the Element. DMX-A feeds three Colortran conventional dimmer racks, about 250 dimmers total.

DMX-B serves 5 outlets where we can plug in DMX toys. I am using three of these outlets to feed two scroller power supplies, one shoebox dimmer pack, and four LED fixtures. All the DMX in and out cables go thru a Colortran control box, with various electronics/splitters, etc.

All the Colortran stuff is 12 years old.

On the A side, there is an intermittent issue. I turn on a few channels at a level. A few minutes later, I notice that group of channels has mysteriously turned off. This has happened not a lot, but maybe 4-5 times over the last week of setting up a show.

Also had the same group of house lights turn ON by themselves, twice during a show.

On the B side, we had one outlet that has never worked. We recently swapped terminations with a good outlet in the DMX cabinet, and everything was fine. Until yesterday.. Came in to rehearsal, and DMX-A was fine. But DMX-B was totally out.. About 30-60 minutes later, it somehow kicked back in.

A friend suggested slowing the DMX-B speed to minimum, which I did. (Both DMX-A,B were set to Max). Everything worked fine for the next 5 hours.

We have show starting in 8 days, and we are all quite nervous.. Thoughts/ideas/suggestions..? Thanks!

 

[Will Elphingstone]

Make sure the DMX cable is actually DMX and not XLR (if you are using 3 pin) And make sure to terminate all DMX runs

 

[JonathanHarpur]

Also make sure the Colortran dimmers haven't accidentally been switched to CMX. It's enough like DMX to work -most- of the time... You might want to run the switch (should there be one on your control module) back and forth a few times just for fun.

When I was running ColorTran dimmers, I'd occasionally (well, yearly) have to clean the contacts on the modules (a delicate and fiddly process), as well as making sure there weren't any airflow issues. (If it's an ENR rack, the control module has a small grate on the bottom right face which did an excellent job of sucking in dust, blocking up the sensor. A quick blast of clean compressed air usually did the trick.)

 

[seanandkate]

All of the above. If that doesn't do it, take advantage of the fact that ETC has great customer service. This fabulous gentleman walked me through some great troubleshooting to determine that a shoebox dimmer had blown out a driver chip in one of my universes:

Technical Support Specialist
Electronic Theatre Controls, Inc.
1-(800)-688-4116 - Factory Toll Free
[email protected]

 

[DuckJordan]

Knowning my past experiences with an ageing Colortran rack, My gut instinct is that its a rack issue and not the board. Likely needs to be cleaned out. Or your DMX to CMX converter is starting to give out.

 

[Mark A Knight]

Having DMX issues.. Running a one-year old ETC Element, which I do not suspect is the issue. (Except maybe there is a DMX speed issue..?)

We run two universes out of the Element. DMX-A feeds three Colortran conventional dimmer racks, about 250 dimmers total.

DMX-B serves 5 outlets where we can plug in DMX toys. I am using three of these outlets to feed two scroller power supplies, one shoebox dimmer pack, and four LED fixtures. All the DMX in and out cables go thru a Colortran control box, with various electronics/splitters, etc.

All the Colortran stuff is 12 years old.

On the A side, there is an intermittent issue. I turn on a few channels at a level. A few minutes later, I notice that group of channels has mysteriously turned off. This has happened not a lot, but maybe 4-5 times over the last week of setting up a show.

Also had the same group of house lights turn ON by themselves, twice during a show.

On the B side, we had one outlet that has never worked. We recently swapped terminations with a good outlet in the DMX cabinet, and everything was fine. Until yesterday.. Came in to rehearsal, and DMX-A was fine. But DMX-B was totally out.. About 30-60 minutes later, it somehow kicked back in.

A friend suggested slowing the DMX-B speed to minimum, which I did. (Both DMX-A,B were set to Max). Everything worked fine for the next 5 hours.

We have show starting in 8 days, and we are all quite nervous.. Thoughts/ideas/suggestions..? Thanks!

If you are still having issues, please contact us for technical support at www.goknight.com. Thank you. Mark A. Knight

 

[JD]

With 12 years in the bank, you probably have more than one independent issue. Looking at the B channel and the DMX outlets, I think there is another part of the system that may be bad. See if you can find a DMX opto-splitter hiding somewhere. Since they are small, they are sometimes overlooked or located in odd places. Since DMX is a chain layout, if you have separate DMX outlets, I think you have a splitter. They do go bad!