DMX is NOT used for pyro, nor is MIDI. While pyro can be automated(as they do in most syncronized music/fireworks show, like at Disney parks), there is dedicated pyro controls and software. These always involve a lot of dedicated wiring that goes to a block(typically) near the stuff that goes boom
Can this be used as an alternative for DMX? No.
Using such things as a MIDI sequence, SMTPE or other time codes and going into a common timing platform(say, ProTools), you can choose something to be the ultimate master reference source. This could be something line ProTools.
Let's imagine a sound and lights show, either something as simple as what the do a Disneyland, or perhaps a full blown concert with performers who are closet pyromaniacs(say, Rammstein).
Let's have ProTools generate a click track and feed that via a matrix input to one channel of the in-ears to the drummer and other musicians who want it, providing the other mix to the other channel on the IEM. This keeps the band ON tempo, and assuming there may or may not be automated backing tracks that go along with that click track, timing is critical. Lighting can be tied to this via MIDI triggers via DMX software package, such as MyDMX or CompuLive.
Likewise, let's say there are also pyro calls, MIDI triggers can also be used to trigger the pyro, which may have to be time off-set to account for the various fuses involved(such as for lift charges and the ones that actually make the pyro explode).
The big difference between light triggers and pyro triggers is that you get ONE shot/trigger on pyro, that's it, while lighting triggers can be used as much as you want since nothing is going to blow up(I hope). Of course, multiple pyro devices can be set off via one trigger.
But, in regards to movement:
There are motors that can be controlled via DMX, of various sizes as well. More common motors are those used in moving yoke and scanner-head/mirror type fixtures, but can also be used for motors that control curtains, risers/lifts, walls and more. It's typically not used for heavier stuff as it's preferable to have a human intervention process for safety purposes, even if that assistance also involves pneumatic or hydralic methods. Usually, it's just flat out cheaper to have humans do the work with or without mechanised assistance, rather than implement custom motors and DMX-chipsets and programming.
Why is there no checking of anything with DMX?
How are you going to do checking with a TX- and TX+ leads? There is no RX+/- leads for stuff to come back. Basic data communications. Or, if you want to get more high-tech, thing UDP, which also doesn't use any error checking.
DMX is a streaming protocol, which means it is constantly spitting out the same information unti it is changed and then alters the stream to reflect the current active data. The worse case is that something might move or change "chunky style" instead of smooth IF you chose to do your programming smoothly. But that's an issue of "what turned out the desired effect".
This is unlike MIDI, which also uses no error checking/control. MIDI sends it and then that's it unless it's continuous controller data that is being used continuously. If your synth or whatever misses that MIDI instruction, then too bad, you missed it. Ever do a sequence and start in the middle of something? You could miss patch changes or note starts. MIDI does have a "Return path", but it's not tied to the outgoing. MIDI uses ground TX and RX. But it only uses ground and TX on a cable or ground and RX on a cable. But the cables are typically wired all 5 pins as a retrofit for those few units that use MIDI-cable supplied DC voltage.
MIDI and DMX use FIXED data rates. This is not like modems where you set your serial port speed high(DTE) and your modem(DTR) can vary based on maximum connection speeds. But, also in that environment, youve got a LOT that can go wrong, so we need error checking, flow control and recovery protocols in place. Not so with DMX and MIDI: it is what it is and that's what it is.
DMX isn't a "lowest common denominator", but I can see where you can get that impression. It's a common platform communication protocol. If you want to play in the DMX512 pool, you gotta speak the DMX512 language. Don't speak it? Can't play. Plain and simple.
You can integrate multiple things into a single computer: audio, MIDI, DMX and even pyro. Nothing wrong with that. Generally speaking, each will use its own hardware. Many audio interfaces may also integrate MIDI functionality(In and out at least, sometimes multiple ports). This makes sense because a lot of people doing audio use MIDI and vice versa. Lighting is more specialized as not all doing MIDI and/or audio need lighting, and likewise, most doing lighting don't need the audio and MIDI functions. So, at this point it makes sense to sepparate the hardware out. Also, each has its own requirements. I know that audio guys(because I am one) and MIDI guys(yup, that too) don't want to cram lighting features INTO our hardware. If we need lighting, we want hardware for that, be it a console and/or software with a dongle. And don't even get me started on the video guys, who need to coordinate with sound/MIDI and lighting, but need their own dedicated systems where it's more critical to tie into audio than anything else, even though if the lighting is going to make the shoot feasible, as a bad shooter can't to crap with bad lighting. But a lightig director can work with the video director to resolve those issues.
Pyro is even more rare. Only the people who truly need this will have this.
Also, typically speaking, we go into the "specialization" aspect.
Even on small shows, I've seen those that use pyro have a dedicated pyro tech, or at least during the show itself, that individual is only responsible for pyro. yes, he may do other things, but nobody else is touching pyro except other qualified pyro techs. Lighting typically has its own tech. Sound has its own tech/engineer.
I know that the pyro chiefs typically have to have certain types of certifications and qualifications in order to hold this position of responsibiliy. Lighting and sound engineers do NOT have to have such credentials as typically nobody's life is on the line other than the sound or lighting guy/girl(bad shows could result in them being killed! No pressure!). If you're flying stuff, you need to have a certified rigger, which could be anyone on your crew. Why? As eluded: safety issues. Pyro goes wrong, people die. Great White come to mind? Rigging fails, people die. Squashed under lighting and lne arrays ain't a good way to go out, unless it's a DethKlok concert. And in the case of a DethKlok concert, pyro problems, rigging problems and destruction, riot and mayhem are why attendees must sign waivers.
Lots of places DO NOT allow any pyro. Before the Great White incident, some would allow some poppers, flashers and some smoke bombs, you know, really low key safe stuff, but had to be done by a qualified pyro tech. After Great White, most clubs and indoor venues flat out banned pyro. Heck, some places banned those silly party poppers for the same reason. I literally saw a bride and groom have to eat a huge fine after their wedding for the party poppers they put out despite being told not to. The staff was collecting them and counting them. All I know is that the conversation started in English and quickly got ugly and reverted to I think Vietnamese.
Pyro can be done safely, but things have to be taken into consideration. What things? Everything. No detail can be overlooked. Low ceilings are a trigger to say "no pyro ever" for safety reasons. More dedicated clubs that were designed expressly for shows(as in, not most clubs) have bigger cielings and don't have such issues, and are using surfaces that are much safer. Even Disney On Ice uses various methods of pyro, but they typically also perform in venues designed for arenas designed to handle concerts, shows and sporting events. At the last Disney On Ice show, they were shooting pyro at each other and some of it bounced on the ice.
So, in the end, you're gonna do multiple runs. Run your audio, run DMX, run pyro, as sepperate runs. It is ILL ADVISED to run MIDI over 50 feet via wire. Tehre are some wireless solutions that work well for this, but are designed for relatively short distances(under 80 feet for reliable performance).
You just want to blow stuff up?