# Embarassing DMX Questions



## DarSax (Sep 1, 2006)

Yeah, all right, I have a confession to make: I still don't really know how that whole "DMX" thing works, even after two years of being a Lighting Director.

Hokay. First off, conventional lights. Light power -> dimmer -> console? DMX Interface? The last step is the one I don't know. I know at school we have a separate box the DMX connects to, which connects to the board, but then again my board is so antiquated that I'm not sure if this is the same with all boards. Could someone tell me basically the connections to control conventional lights?

Second off, intelligent lights. In order to run them on a board, do you basically have to connect them all in series (in the end) in order to connect them to the one or two outputs in your console? 

Third off, DMX/XLR. I know that DMX is what you really _should_ use for intel lights, but I know that we've often used XLR cable instead, and that it's the same. I'm right on this one, correct? Or am I being forgetful, and DMX has 5 pins to XLR's 3? Heh.

Yeah, I've been wondering these things, but a bit too embarassed to ask, because I'm sure the answer is simple. By the way--I don't need the whole explanation of DMX, channels, etc; I just want to know how one would hook up a setup if one was starting from scratch. 

Thanks, and stuff.  !


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## BillESC (Sep 1, 2006)

I'll start at the bottom of your post and work my way up.

Mic cable is rated at 80 Ohms and DMX cable at 120 Ohms. In limited situations, i.e. small number of fixtures or less than 100' of total cable runs mic cable will work. "Real" DMX is designed to operate on 5 pin XLRs, however, at this time only 3 of the conductors are used and many manufacturers have adopted the use of 3 pin XLRs to save money. If the future all five conductors will be utilized as the next generation of intelligent fixtures will be sending status information back to the controllers.

Yes, intelligent fixtures are daisy chained one to the next to the next with one line back to the controller. You can also use opto-isolators to split the DMX data into two or more trunks.

There are two ways to integrate conventional (or analog) fixtures for operation via a DMX console. First if you already own analog dimmers, you'll need a Black Box. A Black Box will translate the DMX signal into an analog signal the dimmers will recognize. If you don't have analog dimmers you'll need to obtain DMX dimmer/relay packs which respond to DMX to control conventional fixtures.


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## jonhirsh (Sep 1, 2006)

You can daisy chain your movers but affter about 26 devices you need to put them on another liine this inclueds dimmers one dimmer rack = 1 device. 

DMX cable vs. Mic cable. Does an $5,000 show seem worth the price of getting the right cable. 


Power Setup

Disconnet ->Dimmer -> Cable To Fixtures
Distro -> Cable To Movers

Data

Console ->DMX -> If dimmers are analog (DMX to AMX convertor) -> Dimmers.

Console -> DMX -> Mover 1 -> Mover 2 -> etc. -> Terminatior on the last mover.


JH


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## DarSax (Sep 2, 2006)

I'd add little "thank you's" to each of your post, but that'd get visually distracting. Thank you very much. (I finally know what isolators are for! Excellent!)

And it'd make sense that we'd need a 'black box,' we have a hard-patch system and the original board was, of course, an analog board. That makes sense, excellent.

Since you had mentioned it, JH, I have another question, about power. What do you guys mean by distros? I've heard that dimmers (unless they're back-packs) are usually powered by the rack and need special power. Then again, from what you were saying, the distro is related to moving head fixtures. I'm ah, a-very confus-ed.

Thanks again though, you've cleared up a ton of my confusion.


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## jonhirsh (Sep 2, 2006)

Distros are used to take 3 phase power and break it down to usable power for a moving light. 

For example I have a 400 amp disconnect i have 20 moving lights the movers are a mixture or 20 and 15 amp, So i have differnt modules that decide which amount of power they are and they have plugs on the back they could be twist lock or soca or edison. based on what amp of power is necessary


Dimmers usualy have power put directly to them as in a sense they are there own distro they just dim the out put of power. based on a console.

check out this site for some pictures of distros
http://www.christielites.com/rental2.php?code=4&name=Distros&linenum=0&totlines=-1


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## zac850 (Sep 2, 2006)

In slightly planer englsih, a distro DISTRObutes power.
The power comes into the panel, and the distro box distrubtes the power around the theater to the movers.


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## DarSax (Sep 2, 2006)

Heh, now I gotcha, thanks. What type of cable goes from the distro to the lights? Just regular AC cable? (I ask, because I don't know where/if we have a distro, we've just used our standard sockets, wall and ND's.


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## cutlunch (Sep 2, 2006)

DarSax The cable used would be AC cable. But whether it is single run cable, ie one cable per plug outlet or a multicore cable that carries many electrical circuits in the one cable depends entirely on how they wired your theatre. It could be a combination of both. Eg mutli-cable to a lighting bar. Single cable to single side of stage points.


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## DarSax (Sep 2, 2006)

Gotcha, gotcha.

In the next few (probably this one) days, I'm going to try and write out the steps to hook up an intelligent light setup, if one/some of you all would be so kind, I'd appreciate it if you could tell me where/if I'm missing steps or if I'm confused about something.

Thanks so much for all of your help, again!


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## DarSax (Sep 2, 2006)

All right, I included a diagram of how to hook up intelligent fixtures, to the best of my knowledge. Is this correct/could someone answer the questions that are in the image? Thanks


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## jonhirsh (Sep 2, 2006)

An opto-spliter. 

JH


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## soundlight (Sep 2, 2006)

To control moving lights with a board such as the Maxxyz, you need to have the profiles for the lights loaded in. A profile is a set of parameters and channels that correspond to the fixture so that you can program colors, gobos, positions, movement, etc. from the board with the encoders.

For example: without a profile, you just have a bunch of DMX channels. Their values can be changed. But you don't know what that channel exactly does at the console without checking the manual and DMX chart for the moving light. A fixture profile (or library, as it's sometimes called) is loaded into the console. That way, you say that you want fixture X to start on channel 1. Any fixture you add after X should automatically set itself on the right starting channel (at least on some boards). On the boards that I've worked on, you can select what fixture you want from a drop-down menu. Once you load the profile, many boards have a joystick and specific buttons for certain functions (movement, gobo, color, focus), and you can use those now because the fixture profile lets the console know what each channel means.

Most ML consoles have a large number of fixture profiles already loaded in, so you may have all of the ones that you need on your console.

I tried really hard to put that into easy terms, and it took me forever to figure it out when I first learned it. Kinda hard to explain.


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## BillESC (Sep 2, 2006)

The fixtures need to be addressed...not the board.


What you're calling a break in is an opto-isolator if those lines represent your DMX data signal.

Yes, Terminator is the term for an XLR male cable with a 120 Ohm resistor across pins 2 and 3.


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## soundlight (Sep 2, 2006)

Oh yeah...dip switch addressing. Many fixtures do it in weird ways, so look in the manual, but most have binary addressing. This means that, using the dip switches, you basically add up the numbers until the channel with which you want to start.

But many fixtures these days have RDMX, which is remote DMX addressing. This means that, if you have the right board, you can address the fixtures from the board.

So, you can set the starting channel from the fixture (and from the board if you have RDMX fixtures), and then you tell the board what channel the fixture starts on so that the fixture profile lines up right. The board then automatically lines up the fixtures that you add in order (just make sure that you have them addressed in the same order that you add them to the board).


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## DarSax (Sep 2, 2006)

Lessee. To the first soundlight post, that actually made a lot of sense, so uh, thanks, and good job. (I'm not a complete stranger to the process, so I had a sort of leg-up, but that still was very easy to understand. Thanks.)

To the BillESC/second soundlight. I think I understand what you're both saying; so you have to go into the on-board computerthing in the fixture, and tell _it_ what channel to start on? (So when it gets data on the DMX, it knows that it's supposed to either do something or ignore the data?)

And gotcha on the opto-isolator, I had seen those in rental catalogs and had no idea what they were.

Thanks so much, again, I've always stressed that one day someone's going to ask me how to hook up these things and I'll have no idea D:


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## soundlight (Sep 3, 2006)

You address the fixture on it's internal computing to tell it on which channel it should start pulling it's data from. It pulls data from that channel on until it gets to the end of it's control channels.

Example: if you have a 17 channel fixture, and you set the starting address to 128, the fixture pulls data from channels 128-144. You have to tell your board which channel you set as the starting channel so it knows on what channel to start sending control commands for that fixture.


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## DarSax (Sep 3, 2006)

Exxcellent.

Gel scrollers would work the same way, correct? You'd have to address on the thing what channels it should respond to, and then you have to load the thing from the library on the board, and assign it channels on the board? You do have a different channel for each color, correct, so you can program in specific colors?


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## jonhirsh (Sep 3, 2006)

Sorta you have one DMX channel per scroller, But DMX uses the values 0 to 255. So when you take controll of a scroller on say dmx adress 01 you then set it between at lets say 123 and that happens to be green. 

you then have the option on most high quality lighting consoles, Such as my perferd console the MA Lite. you can creat an Attribute preset. In this case colour. So when you want that scroller or any scroller you have programed into the preset to be green you just push the pallet that says green. This is a great time saver you can do universal pallets for all your fixtures so you can grab all your fixtures and set them all to green instantly with out any fussing with wheels or numbers. 

Also when you travel a show you can update presets (presets can be postion, focus, colour, beam, and universal which means it records everything listed except timings. ) thus not needing to re do you whole show. 

Now to your comment about you might have to set up a rig, the best way to learn is by being thrown into it. If someone hands you a rental package thats costing them 6 grand for the week you will find a way to make it work. 

JH


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## DarSax (Sep 3, 2006)

Ah! Thanks a lot JH, that makes a lot of sense (and I had no idea, heh.)

And about the thrown into it, fair enough. I was supposed to have already had that done to me last year, but a more knowledgeable guy came in and did everything so that I learned nothing. D:


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## beam_1973 (Sep 3, 2006)

BillESC said:


> Yes, Terminator is the term for an XLR male cable with a 120 Ohm resistor across pins 2 and 3.



Some fixtures also have built in terminators, so you may not need one on the end of every data branch, just check the fixture manuals ... e.g. there may be a second row of dip switches (not used for DMX addressing) that can be used for testing and standalone modes etc ... sometimes, one of these dip switches acts a "terminator".


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## Inaki2 (Sep 4, 2006)

Not ot throw a wrench in here but some scrollers take some stupid math to calculate the address. This is because they use the PSU as part of their channelling, the manuals always have the formulas for them.

Terminators are not always needed, and sometimes can screw things up a bit. They're not an exact science, I know that every book tells you to put them in there "or else", but its not always necessary.

The Maxxyz is a great board by the way. Real easy to use, if you have any previous experience with these kind of boards (ie: more concert oriented than theater) you'll fly on it.


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## DarSax (Sep 4, 2006)

Oh, yeah, that's why I'm getting it, we rented one last year and it took three high school kids with no prior experience and one college kid who had only looked at the manual about two days to be able to work it, with no outside help. Love that thing.

Unfortuatnely, for the show with scrollers that's coming up, I'm going to have to use an Express 24/48 or 125, so now I have to learn to work with those.


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## soundlight (Sep 4, 2006)

I know that the LD at a festival that I went to used an Express 24/48, and set all of the faders to focus points on the scrollers, groups of wash pars, effects, chases, or scroller PS.


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## DarSax (Sep 5, 2006)

Well, my director insists that we actually run the show completely with cues, so that means go go go go go go go go go go go go go go go go go etc, with no faders. Which I suppose will be easier for the scrollers, since I can just type into the console exactly where I want it to go.


Right? Heh.


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## Footer (Sep 5, 2006)

DarSax said:


> Well, my director insists that we actually run the show completely with cues, so that means go go go go go go go go go go go go go go go go go etc, with no faders. Which I suppose will be easier for the scrollers, since I can just type into the console exactly where I want it to go.
> Right? Heh.



The only time subs should ever be used in theatre (rehearsed theatre at least) is if they are linked to cues or they are inhibitive (usually on a touring show of some kind). There is no reason that an operator should ever have to do more then push go. period. Using subs for programing is fine, but when the show is before a house the go button is your only friend.

Also another helpful bit on running scrollers on an expresion console: When you patche your fixtures patch them in groups of 24, ie if your fixture is on 1, put your scroller of that fixture on 25, This will save you a ton of time while staring at your monitor. Also you can link the scroller to the fixture under channel attributes (11 under setup, then hit link softkey). What this will do is devide your trackpad into two seperate parts, one side controlling the scroll the other controlling the dim. While you are doing this remember that strand will actually allow you two bind the scoller to the dimmer via an attribute value....


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## soundlight (Sep 5, 2006)

I meant the fader suggestion as a programming aid, not as a show tool. I understand that it is _much better_ to run a theater show from cues. But hey, whatever works!


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## DarSax (Sep 5, 2006)

Heh. Heheheheeheh. Ehehhhehee, Footer. I've run what...three shows now on a two scene preset?  45 Seconds from Broadway, West Side Story, and The Miracle Worker. Eheheeheh. (Hey so it worked well, gimme a break, this is the first time we've written cues, ever.)

Anyways. With the 1/25 thing, I'm assuming you do that just for organization, so doing it like 1/35 2/36 or whateve rwould be about the same, right? (I have 32 dimmers, so that'd make it simple). 

I'm so excited, too, because we're going to use bubble machines and possibly fog/haze, and for the first time, I might actually be able to run those directly THROUGH THE BOARD! THINK of the possibilities.

Oh, by the way, I'm using an Expression 125, not a 24/48. (Though that is rather trivial)

Anyways, I'm going to draw up (whoo mspaint!) how I'm planning on hooking this show up, if you guys could tell me if what I have looks good I'd be eternally greatful. 

By the way. I'm not sure if my director is going to end up including them or not, but he is thinking of bringing in two moving heads (specifically Studio Spot 575s, which are fine for my purposes and it's what our local rental place has). I'll have the option of either running those through the Express 125 (channels should not come close to being a problem, what with my paltry aforementioned 32 dimmers) or through a computer with Light Jockey. I know from browsing on these forums that using the Express to control ML's is a big pain, but if I can program in the cues, it'd be a big plus on the operating level. Thoughts?


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## Footer (Sep 5, 2006)

DarSax said:


> Heh. Heheheheeheh. Ehehhhehee, Footer. I've run what...three shows now on a two scene preset?  45 Seconds from Broadway, West Side Story, and The Miracle Worker. Eheheeheh. (Hey so it worked well, gimme a break, this is the first time we've written cues, ever.)
> Anyways. With the 1/25 thing, I'm assuming you do that just for organization, so doing it like 1/35 2/36 or whateve rwould be about the same, right? (I have 32 dimmers, so that'd make it simple).
> I'm so excited, too, because we're going to use bubble machines and possibly fog/haze, and for the first time, I might actually be able to run those directly THROUGH THE BOARD! THINK of the possibilities.
> Oh, by the way, I'm using an Expression 125, not a 24/48. (Though that is rather trivial)
> ...



Go with one board, and learn somethnig from it. The reason i do the +24 thing is to keep the control channel on top of the scroller channel. So say I have 24 scrollers on 24 fixtures, each with their own dimmer. The first fixture would be patched to 1 and its scroll would be on 25, the 2nd ch 2 and its scroll 26 and so on. The expression line does 24 ch. per row on the monitor, so this will group them correctly. You will have to softpatch those values in however.


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## DarSax (Sep 5, 2006)

Ah, the monitor part was what I was missing. That makes a lot of sense actually, very nice.

And you say one board? All right, I'll see how that works out (the show's not for many months, and I don't even know if we're renting the movers, so only time will tell on that one; if it's too much of a pain, I might just have one of my lackeys (who's probably going to end up reading this, so hi) run the LJ while I run the Express. Whatever.)


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## Inaki2 (Sep 5, 2006)

LJ? For theater? Weeiiirddddd


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## len (Sep 5, 2006)

Inaki2 said:


> LJ? For theater? Weeiiirddddd



Atypical, but I don't think it's weird. Programming would be a bit of a pain, but making a cue list wouldn't be difficult at all. Just make each scene, save it. Load to a transparent cue, then load cues to a cue list and sit and punch "go." I've done it on a couple shows.


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## DarSax (Sep 5, 2006)

Quick question. If I was to replace a couple of the color scrollers with Studio Colors. How'd I program in the CMY? Is it hard on the Express?


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## zac850 (Sep 6, 2006)

I think the term would be ungainly, not hard. 

The Express line, while it does not have encoders, will not make it terribly difficult to program movers, just make it slightly more time consuming then other consoles.

You can download the profile for the Color Command, patch it into the console and when you select whatever fixture number it will pop up with the pages of commands, and you can fairly easily page between them, using the track-pad to enter everything.

I would suggest you download the Offline Editor (http://www.etcconnect.com/product.downloads.asp?ID=20195) and set it up for the Express 125. You can also download the profiles for the movers (http://www.etcconnect.com/product.downloads.asp?ID=20012) and patch them all together, and see how everything works. Heck, if you have a floppy drive you can even do your entire patch and save it as a show file on your computer, then load it up onto the console.

Remember, the Express has focus points, it has a track-pad as an encoder, so while it won't be as nice as if you had a GrandMA, it is doable.


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## DarSax (Sep 6, 2006)

Ah, gotcha. Thanks.


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## DarSax (Sep 9, 2006)

Just a quick question. This has nothign to do with DMX, but since I kind of self-hijacked my own thread to make it about the show I'm doing, I haff a question.

About how many lux do you need to make colored light appear on a surface in theater? That is, if I have a wash of the stage up, and I have cyc lights on in the back, about how many lux do they have to be illuminating for the color to show up? Thoughts?


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## zac850 (Sep 11, 2006)

There are many variables with that. Mainly, how bright is everything else. For instance, if your stage is pitch black, a very dim cyc will be very visable, but if your stage is lit very brightly, the cyc will be harder to see.

Distance the audience is from the surface is also a factor. Someone else may be able to give you a number, but it is a rather difficult question.


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