Control/Dimming Cell Phone Blackout

MNicolai

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I've heard it rumored that Express consoles are quirky in that cell phone interference can cause them to reboot. Anyone know if cell phone interference can cause a cue stack to clear though?

I ask because I just got this texted to me from an SM:

No clue. We think that it was Jordan's phone which got a text message the moment it happened. The lights shut off and flashed a little before turning off completely. What ended up being wrong is that the cue stack was cleared; we just had to press go. How it happened we have no clue. Again, we think it was Jordan's phone.
 
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I've heard it rumored that Express consoles are quirky in that cell phone interference can cause them to reboot. Anyone know if cell phone interference can cause a cue stack to clear though?

Doubt it. Ran an express for ~5 years in a space with no service (meaning my phone was constantly looking for service) and I never had issues. What type of a phone is it?
 
What it usually is that causes such problems is Electro-Magnetic Interference (EMI), and this can cause problems with computers, and most lighting consoles are just very specified computers in essence. However I've never heard of a Cell Phone being able to produce enough interference to mess with a console. We use an Express and I've received quite a few calls and texts and even used high powered Walkie-Talkies which produce a lot of EMI around the board and we haven't had any problems. Could it have been coincidental user error?
 
I've been sitting behind an Express for three years now and both received and placed countless phone calls and text messages and NEVER* had the board reboot because of it. (Only time the board has ever rebooted the problem was later correctly diagnosed as a failing power supply.) My guess? Someone accidentally hit something with their elbow, was too embarrassed to own up to it, and tried to blame it on "Jordan's phone."

*Of course, now that I've said that I'm going to walk in to work on Saturday and promptly watch my board catch fire. Karma's a ***** that way.
 
The only issue I've ever had is that after deleting the past shows cues and clearing the memory of the board I had them show back up a week later as if they were never deleted. Other than that I've been on expresses for almost 7 years and haven't ever had a reboot or interference like that.
 
Three different phones and four different Expresses in six years and I've never had any sort of problem. None of the combinations ever resulted in anything like you've described. In fact, this is the first time I've ever heard of such rumors.

The board op wasn't messing around in the Clear Functions menu by any chance, were they?
 
Three different phones and four different Expresses in six years and I've never had any sort of problem. None of the combinations ever resulted in anything like you've described. In fact, this is the first time I've ever heard of such rumors.

The board op wasn't messing around in the Clear Functions menu by any chance, were they?

Nope -- this was a student who wouldn't have even known how to get to that menu. Generally they know enough to get through a show via the Go button, but all of my info has come from the SM, and the SM agrees that this is more likely an elbow problem than an interference problem. Multiple people in the booth say that nobody touched the console, FWIW. The SM was backstage at the time so who knows how much "truth-y-ness" there is to that.
 
I've heard it rumored that Express consoles are quirky in that cell phone interference can cause them to reboot. Anyone know if cell phone interference can cause a cue stack to clear though?

I ask because I just got this texted to me from an SM:
Yeah sounds like someone messed up and tried to come up with a cute excuse since 'no one knows how cellphones work' but honestly all the Express is a specialized computer (like all the ETC decks).

BTW heyya neighbor
 
New Info Just In:


Apparently when the lights went out, Express still showed they were up. The director made it to the booth before the SM and started rebooting the console (clearing the cue stack). Then the problem was resolved.

I'm thinking this is maybe a Unison DR rack issue now instead of Express, but it's possible it's an Express problem or something got too much static into the DMX lines?

Console outputs on DMX Out 1 through about 20' of conduit to a dual Legacy Unison DR rack.
 
New Info Just In:


Apparently when the lights went out, Express still showed they were up. The director made it to the booth before the SM and started rebooting the console (clearing the cue stack). Then the problem was resolved.

I'm thinking this is maybe a Unison DR rack issue now instead of Express, but it's possible it's an Express problem or something got too much static into the DMX lines?

Console outputs on DMX Out 1 through about 20' of conduit to a dual Legacy Unison DR rack.


well 20' is absolutely nothing so your run should be safe. The Unisons are well-made systems, it's unlikely you've got a static buildup on the line.

The unison timeout is ~4 mins, do you know how long it had been since the last cue? This could mean the DMX signal was somehow disconnected or dropped. The board would still register as 'up' but the dimmers wouldnt.
 
Express on Unison systems are pretty stable. My thought would be this is more than likely caused by an elbow. Failing that, I'd check the basics; make sure all the right things are plugged in and all the right systems are on and nothing is reporting an error. Then I'd check physical connections and exposed cables to make sure nothing was broken/bent/frayed/chewed/pinched/kinked/etc.
 
The Cell Phone/ Express Interference is real, or at least I was told so by ETC. We had a host of strange issues on one show (cues getting dropped, cues going w/o anyone pushing go, subs flickering (that didn't before or after) and while on the phone with ETC (with the phone on the desk none-the-less we had all kinds of new problems intermittently appearing). I don't remember exactly what they said but it was basically in certain circumstances (I don't think they know why) phones extremely close can cause issues so basically don't sit cell phones or radios on the console. Ironic part is we did multiple shows before that with a radio laying on the console with zero issues and I had certainly left my phone on the console before without issue as well. However it worked, so for what it's worth...
 
I've heard it rumored that Express consoles are quirky in that cell phone interference can cause them to reboot. Anyone know if cell phone interference can cause a cue stack to clear though?

Not sure if interference can cause a cue stack to clear. I can tell you that several older ETC consoles may be susceptible to interference from wireless devices such as cell phones and 2-way radios. Blinking subs, cues running themselves, rebooting, indeed are what we have seen. This is all very rare and is almost always due to the wireless device being placed on the console and it either receiving or sending audio/data.

Think about the power these devices have and decide for yourself if they should be placed on or near your console, computer, laptop, etc. Not me, but then I've, of course, seen what they can do.

In order to sort out what may have happened, more information is needed. I suggest a brief chat with the ETC folks may be the fastest way to deal with this. I'm afraid we might all be jumping to answers without fully looking at the evidence.

The DR rack holds DMX input level for quite a while as mentioned, so it's not as if the console stopped outputting data, UNLESS perhaps they had been sitting in a cue for a long time before the outage. If the lights went down in less time, the console told the rack to do it. You said it's two racks? Well, if a processor had a problem, it wouldn't affect both racks - only one. No amount of static or interference would stop the two processors from receiving data, or more importantly, receiving data they think is all zeros or missing. If for some reason this happens again, and I am not hoping or thinking it will, then a quick look at the DR rack LCDs will tell you if data has been lost.

When you reboot an Express console, it will begin to output all levels at zero unless a sub is up. It's always good to have a sub recorded with a look for just such occasions. How/why did they clear the stack? Knowing what was done step-by-step helps understand what occurred as well.

I know this doesn't answer the question of what happpened but maybe this will narrow it down.

David
 
Cell phones can interfere with other electronic systems. Generally the phone has to be within a few inches of the other electronics to cause a problem. A little space between reduces the signal density dramatically. If you have a phone in the booth keep it a foot or more away from the console. The problem can be worse when cell signals are weak in the building because the phone has to crank up its transmitter to reach the cell tower.

The type of cell network is a factor. GSM uses a modulation scheme that easily causes interference. GSM is used by ATT and T Mobile. CDMA, which is used by Verizon and Sprint, doesn't seem to bother anything. Because I spend much time working on electronic systems, I will only use a Verizon phone.

Condenser mics and some mic preamps are particularly susceptible to close proximity GSM phones, making a nasty buzzing noise when a call or text come in. I always make sure that performers do not have a cell phone in their pocket when I hand them a wireless lav. I have heard the effect of a GSM phone in a breast pocket getting in a Neumann KMS105 mic during a live broadcast. It isn't pretty.
 

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