megabar strobe mystery!

[Phil S]

I have a pair of Equinox megabars which I cannot get to strobe with my QTX 24 channel fader desk. When used with my back-up controller they work perfectly. All I get from my QTX desk is a very slow strobe nowhere near full rate and not usable. I have used different start addresses so it is not a dodgy fader. Both megabars react the same whether connected seperately or paired up, 6,9 or 15 channel. Any fixture I connect to the Qtx desk works perfectly. I do not understand how this can happen. Can anyone enlighten me , please!

[Don Allen]

As this BR post in 2011 says Megabar No Sound not all functions are available on DMX.

 

Sorry, read the manual wrong, there is a Flash channel for each mode, which I did not read as Strobe.According to the manual Sound should be at the top end of Channel 1, maybe different firmware version ?

Edited July 5, 2020 by Don Allen

[timsabre]

What is your "back up controller" which works ok?

[Phil S]

My back-up is a DMX512 192 channel unbranded DMX-DC16.

[Brian]

Pins 2&3 swapped?

[niclights]

From your description it sounds a lot like the control isn't variable or has an uppper limit set or something along those lines.

 

Do the other controls work normally, for example the dimmer and red, green and blue controls? If so is it stuck always strobing at a slow rate or does changing the strobe control have some affect, for example can you get an 'open' (ie. not strobing)? And, if so, does adjusting the control provide access to different strobe speeds but just not the full range?

[timsabre]

is there a display showing the output values? As Nic says it sounds like your faders are not going to 100% - maybe the master control or crossfader not at full?

[Phil S]

Pins left untouched, display on all faders goes right up to 255, master and cross fader set correctly, that is why it is such a mystery. Can get no flash up to a slow lethargic flash but then fader is all the way up.

is there a display showing the output values? As Nic says it sounds like your faders are not going to 100% - maybe the master control or crossfader not at full?

 

 

 

[niclights]

If it is responding then it is not a signal issue. Something must be limiting the output. If you've eliminated fader this suggests master fader/crossfader as Tim says. Perhaps one of these is faulty or needs to be set differently to the way you expect.

 

Are you sure the other controls are outputting at full and not limited? The DMX value for 'slow lethargic flash' might still be relatively high and therefore might not be obvious in the other controls.

 

I'm not familiar with the console but the level display on the faders could be misleading and I wouldn't assume this is a reflection of the actual output on that channel. Do you have a way to check this such as a DMX tester? If not maybe you can try connecting one fixture to one console and the other to the other with dimmer, red, green and blue at full on both consoles and see if you can notice a difference in level.

Edited July 5, 2020 by niclights

[Phil S]

Thanks for your help. I will re-check master and cross faders again in case I have missed something. I do not have a DMX tester but that would certainly help. I may get one! I have a Eurolite DMX move control 512 PRO which I will try on them. Hopefully I will have more info for you. Thanks again.

If it is responding then it is not a signal issue. Something must be limiting the output. If you've eliminated fader this suggests master fader/crossfader as Tim says. Perhaps one of these is faulty or needs to be set differently to the way you expect.

 

Are you sure the other controls are outputting at full and not limited? The DMX value for 'slow lethargic flash' might still be relatively high and therefore might not be obvious in the other controls.

 

I'm not familiar with the console but the level display on the faders could be misleading and I wouldn't assume this is a reflection of the actual output on that channel. Do you have a way to check this such as a DMX tester? If not maybe you can try connecting one fixture to one console and the other to the other with dimmer, red, green and blue at full on both consoles and see if you can notice a difference in level.

[David Duffy]

Could it be that the DMX signal timing on the "bad" console is not the same as the "good" console and the fixture is not tolerant of the difference?

[alistermorton]

Brian might be on the money, though.

[timsabre]

Yes, it isn't clear if only a slow strobe is output and no other control works. If that's the case then pin 2/3 reversal is likely. But if everything else works except strobe is slow, I stick with the master fader theory.

[niclights]

I believe there is control:

 

Can get no flash up to a slow lethargic flash...

[Phil S]

O.K. Done some more testing. Megabars work perfectly with 2 out of 3 controllers so the fault is in the QTX DM-24 dimmer console. I checked all fader values and they all show 0-255 as expected. I then retested the 'bad' desk in every conceivable set-up paying particular attention to master fader and cross fader etc. Still only getting zero flash up to about 20-30% flash rate. Something seems to be limiting output yet any other fixture gets completely normal operation and 0-100% flash rate. All faders work perfectly in playback mode. I have run out of ideas.....over to you guys!