lights blinking on their own.

Allen

I would start by resetting the rack both the unison and the sensor rack.  Often the rack display will give you errors that are good clues to where the problem is.   There are a number of things this could possibly be, The rack has a sensor inside that monitors the incoming air flow and if there is not enough air it will turn lights off to protect the rack, I would advise a complete cleaning.  You will need to start by powering down the entire rack and then cleaning the filter in the door, the individual modules and most importantly the cem.  The air flow sensor is in the front right hand corner of the processor.

Is the room environment that the rack is in very hot??  If the rack is not adequately cooled it will again try to protect its self so that it does not overheat.  This will also give the appearance of flickering lights.

The final test you can try is again with the rack powered down, take a flashing circuit and swap the module (of the same type) with one that is not flashing.  If the problem moves then you know the problem is in the module.

I the above does not help feel free to call in to tec support and we will continue the trouble shooting with you over the phone.

thanks

we have done all of these that you suggested.  even moving the dimmer packs around.  It never follows the dimmer pack.  We have replaced lamps in the source four instruments.  I am just wondering if a ground loop could cause the problem.  We do have a ground loop in our sound system that does cause a hum in the speakers.  I was wanting to know if there is a good test we can do on the dmx cable from the booth to the rack that would tell us if we have any noise or cross talk in the line?  Also would putting an opto isolator inline do any good?  there is probably a good 100' of dmx cable between the board and the dimmer rack.  Is tech support available on SAT/SUN?  if so I may try to spend a saturday on the phone with them to do further trouble shooting.

You could navigate into the Unison Diagnostic menu and look at DMX In/Out of the system to see if Unison is creating the flash, or just passing it along.

You havent moved CMd Cmed, etc arround causing DMX termination issues?

don't think so.  I am going to check tonight before the show just to make sure.

Allen

You can use an oscilloscope to meter out the dmx that what will tell you if there is a problem with the wiring or how it is connected.  Otherwise some dmx testers have a flicker finer feature in it.  If you do not have either of these they are very costly to buy. 

Follow up question, does the lights flicker when you use unison to turn on the lights or is it only happens with dmx??  Is the problem seen in either racks or both rack, for example loads 1 – 24 or 25 - 48 or in both??

At the rack there is a way to do set all by pressing and holding the left hidden button and arrow up until you see set all and hit enter.  Use the up arrow to get to 255 this will set all the lights in the rack on to full.  Does the flickering happen in this setting??  (reset the rack to get out of test mode  lights will go off when you set this up and when you reset the rack to clear the set all.)

What cable type is used for the dmx.  Is it proper dmx cable or by chance did they use mic cable or some other cable to run the data on. 

As for the question of an opto yes it could help but there is no guaranty.

It may be necessary to have you contact a dealer and get the processor in for service.  We try to have loaners available so your system is not out of commissions while it is in for service.  When you contact a dealer they will need the serial ## form the processor and also the version ## of the software inside.

Etc has an Emergency after hours paging system where a tech can be contacted. 

stage light out of houston(they did the install) came out back when the express went out and they were able to test and show that the processor was not this issue.  I do not believe that we have had any issues out of dimmers 25 thru 48 or at least none that I know of.  it has mainly been 1-24.  In particular dimmers 17,18, and 22.  it is usually not a problem when the lights are at full only when we have them between 35% to 65% intensity.  Stage light did turn the processors on and we could see that was not the issue.  Although I do not know if the turned it on at a lower intensity or not.  We are looking at getting an elation opto splitter to be able to split our second dmx channel on the board to have a run to our intelligent fixtures as well as the colortran house light system.  I am not sure if the cable that goes between the rack and the booth is proper dmx or not.  we are assuming that is what Stagelight used when they did the install.  It is odd how everyone talks about 5 pin being the standard for dmx yet the unison only uses three pins on its connection.  Also I need to check but I remember seeing something in the Unison DR install docs last night that showed the jumpers for the termination.  what would happen if both processors have the jumpers installed?  I was going to double check but I think I remember both of the processors having the jumpers installed.

Another way to quickly check if the flickering is caused on the control side, and not the dimmer side is to re-address the dimmers or better yet, address another dimmer to the same dimmer address as the problem ones.  If the additional dimmers flicker the same as the bad ones, then you can probably rule out a bad dimmer module.

As for double termination:  Do you remember back in high school physics when you made a wave on a rope with a fixed end, the wave reflected back 180 degrees out of phase, and when the end of the rope could move free, it reflected back in phase (you were paying attention, right?)

Well, proper termination is in between fixed and free  (for DMX and RS485 it is 120 ohms) such that there is no reflection. Double termination  can also increase the loading on the DMX line which can be a problem with long runs.

Now don't get confused by a CMED feeding a CMD,  In this case, DMX IN ends at the CMED, and is then regenerated out of the DMX Out of the CMED and feeds the CMD.  In this case, BOTH CMED & CMD want to be terminated. (or is it CMed or cmeD or cmEd or whatever...)

Another way to quickly check if the flickering is caused on the control side, and not the dimmer side is to re-address the dimmers or better yet, address another dimmer to the same dimmer address as the problem ones.  If the additional dimmers flicker the same as the bad ones, then you can probably rule out a bad dimmer module.

As for double termination:  Do you remember back in high school physics when you made a wave on a rope with a fixed end, the wave reflected back 180 degrees out of phase, and when the end of the rope could move free, it reflected back in phase (you were paying attention, right?)

Well, proper termination is in between fixed and free  (for DMX and RS485 it is 120 ohms) such that there is no reflection. Double termination  can also increase the loading on the DMX line which can be a problem with long runs.

Now don't get confused by a CMED feeding a CMD,  In this case, DMX IN ends at the CMED, and is then regenerated out of the DMX Out of the CMED and feeds the CMD.  In this case, BOTH CMED & CMD want to be terminated. (or is it CMed or cmeD or cmEd or whatever...)