Shutdown Glitch

G'day

I'm currently touring with an Ion.  When I go to shut down the console at the end of the night, I goto Q 0, then [power off console] from the browser.  When the console powers off, I occasionally get a few lamps that magically turn on.  I have encountered this problem in a couple of venues now.  Short of unplugging the DMX as the console shuts down, does anyone have any suggestions on how to avoid this?

 
Cheers
 

Hi Brent, we haven't seen this here, but we'll try to reproduce it and get back to you. It would be helpful to know if you also see it when you [Exit] from the browser, and then shutdown from the welcome screen. 

No worries Dan.  i'll try shutting down from welcome screen to see if that makes a difference.  I'll give it a few days before getting back to you as the problem doesn't happen consistantly

Cheers

FWIW, I've had the same issue many times with different Expression3s.  I either just wait for the CEM's "hold last look" to time out; or turn the board back on, then off.  It seldom happens the second time.  I think it's just gremlins in the DMX stream.

Brent,

We have two spaces with Eos consoles and Sensor dimmers.  One of the spaces has experienced the same issue through several Strand boards and several ETC boards.  It doesn't happen every time, but quite often.  Usually it is just one entirely random light.  We just walk away knowing that it will go away when the DMX times out. 

Are you using House racks or Road racks?

Surely, we are not the only three places that experience this.  It seems harmless but still interesting.  Derek, I assume you are referring the Sensor racks as well?

Brent

Tennessee Performing Arts Center

I have this problem often in my space when turning off an Express 48/96 with a single SR48 Sensor with CEM. The main problem is that when it holds those one or two dimmers on, it is infinite and not the 5 minutes the rack is set to hold a look when DMX is lost.

In the past I've encountered this kind of problem no end of times when we were using Virtuoso DX - every time we turned the console off it was likely that one or more lights in the rig would turn on. It seemed to be most prevelant with Strand LD 90 dimmers, but I remember one theatre with Strand EC90 dimmers where it would happen every single time the DX was turned off. I've also seen the problem with Strand dimmers by just unplugging a DMX cable from a live console - so my guess is it is more of DMX receiver issue than a console specific issue.

People! This has been around as long as we have had DMX. Every console does it and it just depends on the distribution gear you have and whether or not it will hold the "glitch". I call it the DMX death gasp. The way it was explained to me from people far smarter than I, it has to do with there not being any sexy way to stop the dmx message, so inevitably sometimes a message shoots out garbled from your console when it stops sending, thus making a random set of channels go to weird levels.

Jason is correct.  DMX is being sent all the time which means that anything that interrupts this activity can cause dimmers to glitch. With the addition of "Last Look Hold" features in newer dimmer racks (since Sensor as far as ETC goes) these glitches get latched  and held until the timer lets them go.

When consoles are powered down there is a brief amount of time where the DMX is still being transmitted yet the power supply is running down.  This may corrupt part of a DMX packet which is recieved and then latched by the racks.

There are ways to resolve this but some solutions involve adding components on the DMX output which I'm not quite in favor of for the sake of reliability.

There you have it.  Sorry it's not a better answer.  Some racks and consoles do it more than others and you may nede to make a concious decision betwwen the amount of Hold Time versus power down glitches at the end of the day.

David 

Fair enough. This is my first time I've spent any serious amount of time with an ETC console. The consoles I've previously operated / toured in the past have very rarely experienced this problem - maybe once or twice on a 32 venue / 150 performance tour.

Unfortunatly, I don't always have the luxury of being able to adjust the "hold time" on dimmers as the venues we tour to may not want to change it specifically for our show, as they are just going to have to go and change it back.  

Just putting the idea out there - is there a way of making this neater on the console end so this problem doesn't occur, or is this just a part of life that I have to get use to.

 Thanks to all for their input and info!

Cheers
 

I never saw that behavior with my Obsession 600, but now with the IONs it is every shutdown.  There are no channels up, DMX is totally empty, but it flashes a random channel on shutdown.  In our smaller space, that means the Sensor dimmers hold that information for 5 minutes.  In the larger, the IPS merely flash and then go dark.  The channel is completely random, always at full.  Sometimes it is a very saturated and powerful instrument and I have to reboot the board and then shut it down again so the color doesn't burn.