Automated Fixtures Going where DMX has never gone before. Help?

[TNasty]

So at my school, we like to say that "Anything's possible in Theatre, except for getting a decent budget".

With that said, I've just taken on the task of sound and light management for this Fall's production, and the team is making some big changes. Replacing the light board with a computer running Lightforge, setting up three projectors to throw imagery onto the upstage curtain, and installing two Technobeam fixtures we had laying around.

I've got everything planned out, but we're currently unsure about how we're going to get the Technobeams connected to the system- We don't have any DMX or standard 120v connections that are in convenient locations for the fixtures, and we don't have a way to easily run new cabling in the walls. Conversely, we have loads of Twist-Lock connectors in the room, some even in places that make me question the sanity of the designers. Since the TB's need a 3 pin DMX connection, I got the idea that I could retrofit existing cables with 3 pin DMX terminals, and then just chain it into the DMX line at the dimmer rack.

Does anybody have any clue if this would work? I've got lots of prior electrician experience, so I could certainly do it, but I don't want to try it without a few opinions.

 

[theatricalmatt]

Have you considered wireless DMX?

Before adapting existing cable (especially anything installed in the walls) you should be certain of the type of cable it is, and what it might be hooked up onto the opposite end. Where does the twistlock go? Is it 120v or 240v? What gauge cable is it? What else is run on the same circuit?

I wouldn't consider adapting the twistlock to DMX, but if you're able to get the twistlock to pass 120v power -- maybe it means putting an adapter at each end and plugging it into the wall -- then you could get a wireless DMX receiver and plug both it and the Technobeam into constant power. But I would definitely check to make certain of where it goes, if it goes anywhere. Not to difficult to do with a cable sniffer.

 

[Amiers]

Depends on the cabling you want to refit.


Scroll down to Cabling that should answer your question in full.

http://www.acclaimlighting.com/support/about-dmx.html

 

[TNasty]

Thanks for your quick responses.

What I'd wind up doing is I'd be getting behind the dimmer rack and disconnect the proper cables from their dimmers and jerry-rigging them to carry what I need.
So my current understanding is that I'd certainly be able to convert the cable into a constant 120VAC source, but I'd have to see the construction and design of the cables to ensure they meet the requirements/recommendations before I convert them to DMX.

I'll take a look at the wireless DMX deal, since that might be great if the units ever need to be relocated. I just hope they have a good range and don't cost too much, since we've already gotta buy the DMX output for the computer and replace some neglected microphones.

 

[tyler.martin]

Converting 12/3 Cable to DMX Signal is nothing but a recipe for disaster. One mis-wired connection and your console and fixtures blow up when they recieve 120v to the DMX port. DMX is a robust-ish protocol but it can be very picky about the cable you use to carry the signal. Most of the time we use 1pair 22awg shielded cable.

Invest in wireless DMX or string a cable from your booth to the fixtures.

 

[Les]

What I'd wind up doing is I'd be getting behind the dimmer rack and disconnect the proper cables from their dimmers and jerry-rigging them to carry what I need.

...but I'd have to see the construction and design of the cables to ensure they meet the requirements/recommendations before I convert them to DMX.

They do not.

It has been said that you can run DMX down a barbed-wire fence, but I don't think running DMX down what is probably THHN wire would give you good results. For starters, that wiring probably ends up in a conduit or raceway bundled with other line-voltage wiring at some point. That means that it will be illegal by NEC standards since you'd have low voltage/signal lines sharing space with line voltage, which will present some significant safety hazards. Then there's the practical issues of having all kinds of signal interference — both from being in proximity to line voltage and the fact that these conductors are not shielded.

A better plan for those receptacles would be to get them on a relay module in the dimmer rack. Depending on your rack's model, that may be as easy as buying a module and sliding it in place of a dimmer, or as difficult as contacting an electrician to move the wires to a non-dimmed circuit.

 

[RC4Wireless]

Give us a call on Monday morning. If you're in the USA or Canada, we can loan you an educational evaluation kit for our RC4Magic-900 wireless DMX system, which is 900 MHZ with the longest range in the industry. If you're elsewhere, we can send a 2.4ghz kit.

You'll be very pleased with this solution.

Jim
RC4 Wireless
866.258.4577
theatrewireless.com

 

[BillConnerFASTC]

DMX runs really well on CAT5 wire - even patch cords - ands it's cheap.

If you have dmx somewhere, this part shouldn't be hard. If console us closer, think about a splitter from there. And the aforementioned wireless is a good option for relative ease, if perhaps more costly.

Power is power - and a nearby convenience outlet would be fine - just run an extension cord (not through walls though).

 

[STEVETERRY]

Thanks for your quick responses.

What I'd wind up doing is I'd be getting behind the dimmer rack and disconnect the proper cables from their dimmers and jerry-rigging them to carry what I need.
So my current understanding is that I'd certainly be able to convert the cable into a constant 120VAC source, but I'd have to see the construction and design of the cables to ensure they meet the requirements/recommendations before I convert them to DMX.

I'll take a look at the wireless DMX deal, since that might be great if the units ever need to be relocated. I just hope they have a good range and don't cost too much, since we've already gotta buy the DMX output for the computer and replace some neglected microphones.

I would suggest that you don't "get behind the dimmer rack" until you have a better developed plan that does not involve trying to send DMX512 down conductors intended for 120VAC. I think you need some experienced help with this project--for your own safety, please seek it out before doing anything.

ST

 

[TNasty]

I would suggest that you don't "get behind the dimmer rack" until you have a better developed plan that does not involve trying to send DMX512 down conductors intended for 120VAC. I think you need some experienced help with this project--for your own safety, please seek it out before doing anything.

ST

Okay. Last evening while I was sitting around, I realized that we have two DMX drops running from the booth to the dimmers, even though we run all the units on one universe. That made me wonder if I'd be able to "reverse" that second run to bring the DMX back from the dimmers up to the booth, and just mount the TB's in Cloud 9 which is right above our booth. You can see the second DMX run in the attached image.

 

[BillConnerFASTC]

If the console is in the booth, why not just run DMX from console to wiggle lights?

 

[TNasty]

If the console is in the booth, why not just run DMX from console to wiggle lights?

I would consider doing that, but we are going to be upgrading from the current board to a computer with a DMX breakout, which will only have one DMX out.

 

[Thetechmanmac]

Going off of what Bill said, you could run DMX from computer to the technobeams, out of the technobeams and to the dimmer racks, via the DMX input panel in your booth.

PS @BillConnerFASTC I like that term 'wiggle lights' maybe I'' start calling movers 'wigglers'

 

[TNasty]

Going off of what Bill said, you could run DMX from computer to the technobeams, out of the technobeams and to the dimmer racks, via the DMX input panel in your booth.

PS @BillConnerFASTC I like that term 'wiggle lights' maybe I'' start calling movers 'wigglers'

I didn't realize he said 'wiggle lights' until I saw your comment.

Going straight to the Wigglers could work, and if I remember correctly, the fact that they use 3 pin instead of 5 pin DMX doesn't hurt anything down the line since the two extra pins are "empty".

 

[BillConnerFASTC]

Or get a splitter or second dongle.

 

[RickR]

If you have DMX in 5 pin and 3 pin get a few sets of adapters! Life will be far easier until some one loses or steals them.

Sent from my SM-G900V using Tapatalk

 

[RickR]

Oh yeah, the barbed wire thing was just a stunt, but folks have done far stranger stuff with DMX.

Sent from my SM-G900V using Tapatalk

 

[TNasty]

So my friend and I were taking inventory on all the equipment we had laying around, (we found some real wacky stuff, like a box full of 40+ Telex wireless receivers, but no transmitter, a 20th century baby monitor, and some old printed out emails), and we scrounged up some DMX cables. We have enough to link the two Technobeams in C9 down to the lighting board, but not all the way back to go to the dimmers (we'll spend some money on a cable).

Now we've just gotta order the new motor drivers for the fixtures, and wait half a month for Chinese shipping. On one unit, just the iris doesn't work, and the other has hardly any operational functions. All the motors move freely, they just don't move when they should during homing and testing.

 

[Fountain Of Euph]

If you have DMX in 5 pin and 3 pin get a few sets of adapters! Life will be far easier until some one loses or steals them.

Sent from my SM-G900V using Tapatalk

I ordered spares since I keep loosing adapters. The package with the spares got lost.... the same day I lost my adapter....

Sent from my SAMSUNG-SM-G730A using Tapatalk

 

[derekleffew]

Or get a splitter or second dongle.

I ordered spares since I keep loosing adapters. The package with the spares got lost.... the same day I lost my adapter....

Perhaps obtaining a D-Split (or similar) with both kinds of output could solve multiple issues.

An opto-splitter at the "console" is preferable to either
a) looping thru fixtures on the way to the dimmers, or
b) running from the booth to the dimmer rack then back to the booth then on to fixtures.
Don't forget terminator, DMX where applicable.

... (we found some real wacky stuff, like a box full of 40+ Telex wireless receivers, but no transmitter, ...

Possibly intended for a forgotten/abandoned ALD ?