DMX Lighting

[synaesthesia]

Hi, I'm gonna hijack this thread a bit rather than start another one as I understand DMX is a little niche (in our world anyway!)

We usually have a company come in to do all our sound and lighting, and this year said company isn't available  However this seemed a good opportunity to extend our production to allow students to help manage the backstage stuff too!

Sounds great in practice, however there's literally noone who has a single clue about the systems in place! The previous network manager apparently gatekept everything and documented nothing - the little information I do have appears to be extremely wrong. We have a lighting desk, a mixture of DMX outputs in our A/V cabinet,  3 bars of lights, a wall mounted DMX controller which looks simple but isn't, but no means to connect more than one bar.

 

So I'd love a little sanity-check from people with more experience than me please! Until last week, I knew absolutely nothing about lighting. I've read a lot and think I have a reasonable understanding now, but that might classify me as "knowing enough to be dangerous but not enough to be useful"

 

So we have 3 bars of lights, from what I can make out all daisy-chained and each has an output in the A/V cabinet. Bar 1 downstage has a dozen fixtures, bar 2 midstage has 6, bar 3 backstage has 4 led strips.

I can connect any of them to a basic controller and get most of them to at least do something.

Our desk is a Zero88 Jester24 - ancient - and muppet here factory reset it, removing all the presets but I don't think that's major as the presets match the documentation i have regarding starting DMX channels, all incorrect.

I've managed to get some basic addresses for some of them doing something suggested in this thread, cycling through the channels until something reacts and making a note of that starting address. Got confused when some of the lights started doing different things on different numbers, so assume there's some channel crossover.

 

Biggest thing I want to check is connecting all these lights together - I believe we need a DMX splitter - tentatively looking at https://www.amazon.co.uk/Micvtve-Amplifier-Splitter-Distributor-AC100V-240V/dp/B0CH7S4QG3

I can't seem to verify if this is actually what we need as the documentation appears to suggest these are for splitting to each separate fixture - does anyone know if they will work on chains?

 

When rummaging around various departments I've found useful looking things like an Airstream DMX which I'd love to be able to use, especially bearing in mind it'll be students running the shows. Got it working on a basic 2 light chain in testing so fingers crossed it'll cope with all of the main lights!

 

Any useful tips appreciated. I'm fairly sure the person responsible for the DMX standard and the terminology used is the same person responsible for things like Github - entirely overcomplicated for something actually quite simple!

[flipthebit]

You could have them all on one chain. There might be reasons where it's best not to. We have 16 fixtures on 3 bars with one cable between them all.

 

Fixtures can use different amounts of addresses depending on how you want to use them. Less addresses mean less options, but more fixtures in total. Knowing where every fixture address starts would be useful. Then lookup the fixture and see how many addresses they need depending on the feature you need.

 

Once you've got your desk working make a backup of the config to USB,

[TronXP]

Hi,

 

If you have a dmx cable from each bar,  then using a DMX splitter will do what you think,  it is good practice to put a DMX termination plug into the end of each chain.  Splitter quality can vary,  I tend to use the Chauvet data stream 4.  The other option as above,  (if possible) is to chain the last fixture on one bar to the first fixture on the next bar and make one big chain.

 

If you can get the name of the fixtures on the bars,  find the manuals,  this should give you the number of dmx channels each fixture uses and what each channel does. 

 

 

[Andrew_C]

As above - daisy chain is simplest (usually) and cheapest.  Some devices auto terminate, sometimes you can just get away without.  Don't. 

[synaesthesia]

Cheers. Thankfully have the fitting details so I've a good idea of the basics, however I think all but 2 of the lights are configurable (i.e. you can choose between 7 channel and 14 channel modes) which makes life a little more interesting!

I'm making assumptions there's terminators in place, trying very hard to avoid having to go up a ladder to check - but I think this might be unavoidable

Budget is nearly non existent, but might try and get the school to stretch to the Chauvet - a couple of the fittings are Chauvet

 

[robk]

@synaesthesia Sounds like you need a DMX splitter to get signal to each bar, (think switch multiple machines, each machine having 2 network ports and you are not far off DMX...).

 

You could just use faders on your desk to work out what is in what "where" in the rig. If you know the first fixture is Ch1 and for example is a LED flood it will then give you Red Green & Blue on CH1, 2 & 3 respectively. 

 

Once you have a map you can rebuild the programming on the desk.

[synaesthesia]

Yup, all figured out now and we're all good  Bought the Chauvet 4 way splitter in the end, could have gotten cheaper but 80 quid for something we know will work isn't exactly expensive.

 

I'd like to shoot the muppet that set them up in the first place I think but the important thing is it's working in time for the production and the desk is going in the bin - using an Airstream DMX controller it can all be done via iPad or laptop and it's just a million times better.

 

Spent a lot of time over the weekend documenting it, so no more surprises in the future!

Edited March 9 by synaesthesia