DMX safety for non-lights usage

[SanTai]

We all know the DMX standard clearly state that it should not be used for pyro, machinery or other dangerous stuff.
That is very true, it can however be used for cueing. In my view the most dangerous part of DMX combined with SFX/Machinery is that people used to lights know how to use it. Controlling anything from the booth except lights(and maybe sound and video) is dangerous no matter what kind of controller you use.

So, done with rant so we might be able to discuss the product below without having the usual DMX-Safety talk.

MagicFX | Make your audience scream!

It is a non custom dmx switch pack with a safety channel. If I understand it right, it needs the safety channel to be at a specific value for 3 seconds for the unit to arm. All of us that do pyro know that you do not arm if it is not safe to fire. This should eliminate the problem and risk with signal errors. Am I missing something?

Am I missing something or shouldn't this be safe to use for say confetti launchers, kabukis and similar that are not allowed to fire early and can be dangerous. With some extra safety features it could probably be used for propane flames.

 

[cpf]

I'd still say it can be misused - park the safety channel at the magic value (for convenience!) and it's back to being a normal relay pack.

This is why most potentially-dangerous SFX control systems have a dedicated-hardware, proprietary, impossible-to-avoid-using-even-if-you-just-bypass-it-with-a-brick deadman's switch - it encourages the proper safety practice of having a designated, dedicated (for the required period of time, at least) crew-member nearby at ground level to watch the effect and prevent it from being remotely started if doing so would be dangerous.


But in the end, no matter how many safety features the whatever has tacked on, it's a matter of everyone involved knowing and following safety protocols. It's impossible to engineer out incompetence and unsafe behavior.

 

[BobHealey]

When I needed to use DMX to trigger confetti cannons (by plugging them into a relay pack) (for timing purposes, to sync with an lighting and sound effect), I built a pair of deadman's/enable switches for the 120V line between the pack and the unit. I wanted to make sure those that even if the board or the relays went haywire, those things would not fire and launch a load of paper into someone's head or back. I had an enable switch at the stage for the SM, and the deadman's was with me in the light booth because i had an unobstructed view of the entire stage and downrange. Most likely, nothing would have gone wrong just using the relays, but I decided it was better to not fire the effect at all than misfire it. CO2 confetti, not pyro, otherwise I would have done things more safely.

 

[chausman]

I still say no. DMX still isn't reliable enough for my taste. Just look at the threads talking about MHs. Most issues are caused by weird reflections or other funky stuff you can't be sure about until you try it out.

 

[SanTai]

Okey!
I wanted to discuss the technology. Not how to protect the world from stupid people. But,

That it can be miss used is an extremely unrelevant point. You can disable every safety feature in every system, they are not there to protect from the user. Do you know how easy it is to put the dead mans switch out of play on my Pyrodigital(The most prestigious dedicated pyro controller)? Nothing protects from fools. Sorry cpf, but you are miss informed.

Chausman, sorry to disappoint but on almost all the large flame systems, dmx ARE used for cueing.

BobHealey, you are too far away to have a good view from the booth. Even when doing confetti I would strongly recommend to have your pyrotechnician holding the dead mans switch. He SHOULD know where he should stand.

The interesting thing is, will this protect from reflections at all times the safety is not activated. I believe it should, because my knowledge of electro magnetic field theory, tells me that even in lab distorting the signal in the right way to get a 3 second burst at a specific value is kind of undoable. Am I missing something? Are there more vulnerable parts of the switch pack?

 

[chausman]

Chausman, sorry to disappoint but on almost all the large flame systems, dmx ARE used for cueing.

As a method of cueing a technician, or actually executing that cue?

 

[cpf]

I'm not sure what you're doing with this thread. If you are so well informed and experienced, to the point of categorically declaring that other people are wrong, why are you coming here for an opinion?

 

[SanTai]

I'm not sure what you're doing with this thread. If you are so well informed and experienced, to the point of categorically declaring that other people are wrong, why are you coming here for an opinion?

I am sory for coming on strong, but I wanted to get opinions on the technology since it is essentially a lightning controller. I did not asked for info about pyro controllers. I didn't want a general safety discussion since it has been discussed so many times before. Another reasons is that do not want people buying this switch pack, hook it up to their lightning dmx network and think that is all the safety needed for pyro, confetti, kabuki, machinery or anything else. Discussing safety procedures on the Internet could even be dangerous since it could get people too think that it is enough to have read it in a forum and they do not need supervision of someone with any experience.

I wanted to discuss technology and see if anyone had any experience about other failure points than the one it is supposed to protect from. Strictly the technology.
Sorry for sounding like an ass but I rather be the bad guy on a internet forum, then give some random reader the idea that they know enough. And then we have another Station fire on our hands.

 

[SanTai]

As a method of cueing a technician, or actually executing that cue?

It is NEVER on the same DMX-network as the lights. But, yes it actually executes the cue. There are several safety systems in place and a few dead mans switches(un related to the DMX cueing) but lets not get into that part.

 

[josh88]

Even separate from the lighting it's still Dmx and dmx still isn't safe for running that kind of stuff. Too many variables. Just because because it's separated out from your lighting control doesn't make it any more reliable. I wouldn't run anything off of it personally.

Also how could you know bobhealey doesn't have a good view from his booth? Do you know the distance or where his booth is or what kind of video feeds he has running? His setup would be the only thing I've seen mentioned that I'd be relatively comfortable with. This seems to be a rehash of other discussions we've had


Sent from my iPod touch using Tapatalk

 

[SanTai]

Even separate from the lighting it's still Dmx and dmx still isn't safe for running that kind of stuff. Too many variables. Just because because it's separated out from your lighting control doesn't make it any more reliable. I wouldn't run anything off of it personally.

Would you care to elaborate?
Except for the risk of signal error with no error checking, which is what this is made to protect from. Which are the risks?

Also how could you know bobhealey doesn't have a good view from his booth? Do you know the distance or where his booth is or what kind of video feeds he has running? His setup would be the only thing I've seen mentioned that I'd be relatively comfortable with. This seems to be a rehash of other discussions we've had

Other setups have not been discussed. About the view, was of course a guess based on my experience of were in a venue the booth is placed.
I have never seen a pyrotechnican rigg the main safety FOH and very seldom at all FOH, then only because of show control cabling. You should always have one person dedicated to the task, even if it is "just" CO2.

 

[derekleffew]

I'm not getting in the middle of this, but wanted to offer an anecdote.

Recently, I had a colleague call to ask how to build a terminator, DMX , as he was on a tour and at one stop his confetti cannons accidentally went off just before doors. I directed him to the wiki entry. I didn't tell him I doubted that a terminator would solve his problem, as that's not what he asked. I'm sure I've seen other stories of accidental, unwanted discharge here on CB.

Using a DMX "safety" channel that must be at a specific level or go through a specific sequence, is a good idea, but does not totally mitigate/eliminate the possibility of a misfire. Look up the process of how to soft reset a Cyberlight sometime.

 

[SanTai]

I'm not getting in the middle of this, but wanted to offer an anecdote.

Recently, I had a colleague call to ask how to build a terminator, DMX , as he was on a tour and at one stop his confetti cannons accidentally went off just before doors. I directed him to the wiki entry. I didn't tell him I doubted that a terminator would solve his problem, as that's not what he asked. I'm sure I've seen other stories of accidental, unwanted discharge here on CB.

Heard those as well. However they have always include that the operator did not take any precautions.

Using a DMX "safety" channel that must be at a specific level or go through a specific sequence, is a good idea, but does not totally mitigate/eliminate the possibility of a misfire. Look up the process of how to soft reset a Cyberlight sometime.

Now I have... Now what? You put one channel to one value and then another to zero...

 

[DuckJordan]

I would prefer a secured network, Not just a DMX solution. There were reasons (when i worked at a very large pyro firm, think 4th of july at large hotels and such) that we had a key system. No key, no fire. One man with the key if that person where to release pressure on the momentary switch triggered by the key then no fire. It was fired off a 12v relay system. Computer controlled but not DMX. It ran off Ethernet and had error checking as well as a local copy and the remote copy of the "Show File". if it sensed a slight dip in the 12v or a slight increase in voltage the system shut off. I'm sorry but no new information in this thread is relevant, all that device does/is a dead man switched relay. Thats it. Its a lot easier to get a channel to stay at a level than to have someone physically turn a key.

 

[BobHealey]

Also how could you know bobhealey doesn't have a good view from his booth? Do you know the distance or where his booth is or what kind of video feeds he has running? His setup would be the only thing I've seen mentioned that I'd be relatively comfortable with. This seems to be a rehash of other discussions we've had

I'll be the first to admit what I did wasn't ideal, but based on the sight lines open to me and the onstage crew for the musical, and the time and budget I was operating under, I did the best I could to make the effect as safe as I could. I would not have run it off the DMX device (ETC Sensor rack with R20 module), without the inline switches on the 120V feed to the gun. Would I do it better next time? Yes. Should I have refused to do the effect at all without a real effects controller? Probably.

 

[SanTai]

Here you got some info about pyro controllers:

PD:
Pyrodigital Consultants Electronic Firing System

F1:
Welcome to FireOne™ - The Photoshop(r) of the Fireworks Industry!

Galaxis:
Galaxis Showtechnik - Professional Wireless Firing Systems for Pyrotechnics

PD and F1 are the most common in the pro world, with generally PD having a better reputation. Galaxis is a newer system which is made to be wireless. All these are used by mayor companies and have been used at La Ronde. La Ronde have a special PD and F1 setup with amplifiers and what not.


I'm sorry this thread as usual could not hold the topic, that switch pack was never intended for pyro. It was intended for all those usage that yet lack a dedicated controller and were it seems the industry is going to us dmx for cueing.(Flames(NOT pyro), co2, kabuki, konfetti etc.)

 

[DuckJordan]

Here you got some info about pyro controllers:

PD:
Pyrodigital Consultants Electronic Firing System

F1:
Welcome to FireOne™ - The Photoshop(r) of the Fireworks Industry!

Galaxis:
Galaxis Showtechnik - Professional Wireless Firing Systems for Pyrotechnics

PD and F1 are the most common in the pro world, with generally PD having a better reputation. Galaxis is a newer system which is made to be wireless. All these are used by mayor companies and have been used at La Ronde. La Ronde have a special PD and F1 setup with amplifiers and what not.


I'm sorry this thread as usual could not hold the topic, that switch pack was never intended for pyro. It was intended for all those usage that yet lack a dedicated controller and were it seems the industry is going to us dmx for cueing.(Flames(NOT pyro), co2, kabuki, konfetti etc.)

Flames are pyro co2 falls under that category here in the us as well.

 

[SanTai]

Flames are pyro co2 falls under that category here in the us as well.

Which legal category it falls under is kind of irrelevant. Pyro controllers are not constructed to regulate how long they fire. They usually just empty a capacitor through the e-match. Makes them useless for a lot of modern SFX machinery, keep in mind that PD and F1 got pyromusicals as their primary purpose. That is why DMX is used. Galaxis got rudimentary possibilities to control this kind of machinery, but it isn't quite there yet, to be useful.

More than the signal error part, have you had any other kind of issues with DMX?

 

[DuckJordan]

Yes, I've had no signal what's so ever a loss of control from face plate to processor. And complete random restart of fixtures and console cause by dmx failure.

 

[SanTai]

Yes, I've had no signal what's so ever a loss of control from face plate to processor. And complete random restart of fixtures and console cause by dmx failure.

All of those seems very easy to protect oneself from, part/all depending on what the failure was I believe it is already made to protect from, so that we do not get any catastrophic failures.

To me it feels like, that if you just put an arm switch and a dead mans switch on the AC-power and on the DMX line you've got a good control system that uses DMX. I think I will have to request a datasheet to have a look at have an EE look at.