DMX Advice

[Bentgh]

Hi!

I've done a few bits of work in theatre before so I understand the basics but for my school show my teacher has asked me to help rig and as I've never set up an full show before using DMX I'm a little confused so was hoping someone could help me!

Am I right in thinking that I using a dmx cable, I plug that into the desk then into a dimmer and then from the dimmer I daisy chain the dimmers till I reach that last one and then link the dimmers up to the fixtures using dmx cable?Or am I completely wrong?
Any help will be appreciated! Specifically help on how to kind of link the whole system up of what cables to use.Or if anyone has any good, clear diagrams?

Also, I was wondering, how do I plug my console into a dimmer if the dimmer is far away? Is there an inbuilt system? As far as I know, next to where the lighting desk goes there is a panel on the wall with lots of sockets which look like dmx cables can be plugged into, will they be connected to the dimmers?I know that may be hard to answer since you don't know my set up but if you understand thanks! Haha

 

[derekleffew]

...Am I right in thinking that I using a dmx cable, I plug that into the desk then into a dimmer and then from the dimmer I daisy chain the dimmers till I reach that last one ...

Correct so far.

... and then link the dimmers up to the fixtures using dmx cable?...

No. At the end of the DMX chain, you plug a terminator. Conventional fixtures don't use DMX512 cable at all, just mains (line voltage) cables (possibly Schuko or CEEform cables in your locale) to connect them to the dimmers. One can continue the DMX daisy-chain through moving light or LED units--these require both constant (non-dimmed) power and data.

From Doug Fleenor Design - DMX Basics :

A simple system.


A complex system using opto-splitter s.

.

 

[len]

I believe there's some wiki stuff on this site, but I'm not sure where.

Also, some limits to dmx data as far as number of fixtures on a dmx run, type of cable, etc., that you should learn about.

There's also stuff about splitters, termination, etc., you'll need to learn.

But don't get frustrated. There's a lot to learn so expect that you don't know everything, and that no matter how long you've been at it, there's something new to learn. I've been working with it for like 15 years and I still don't know 90% of what I should.

 

[Chris15]

just mains (line voltage) cables (possibly Schuko or CEEform cables in your locale)

Or possibly those bulky standard UK plugs, but I seem to recall someone telling me that you weren't permitting to use those for this sort of thing and so Ceeform ie, IEC60309 was the norm in the UK (aka those blue plugs...)

 

[Bentgh]

Correct so far.
No. At the end of the DMX chain, you plug a terminator. Conventional fixtures don't use DMX512 cable at all, just mains (line voltage) cables (possibly Schuko or CEEform cables in your locale) to connect them to the dimmers. One can continue the DMX daisy-chain through moving light
.

Thanks! That's helped!
However, what to I connect the moving lights too? Just each other using dmx? Or do I have to daisy chain them all then link them back to the dimmers or console or something?

 

[len]

Thanks! That's helped!
However, what to I connect the moving lights too? Just each other using dmx? Or do I have to daisy chain them all then link them back to the dimmers or console or something?

A dimmer is a dmx device. So is a moving light, or a fogger (most of the time), etc. DMX is the control cable and yes, devices get linked together. You can have a dmx chain that is -- controller -- dimmer -- moving light -- fogger -- dimmer -- dimmer -- fogger -- moving light, etc. The order of fixtures in a chain doesn't matter. Nor does the address of each dmx device. The starting address of devices could be completely out of order. Like -- 16 -- 437 --- 24 -- 155 -- 199, etc. The main things to watch when addressing dmx devices is that each device be assigned a unique starting address, and that no device overlaps addresses. For example, an LED par can typically uses 3 - 6 channels of dmx. For this example, we'll assume it uses 3 channels. You address that LED par can to channel 1. So Red is 1, Green is 2, Blue is 3. The next available address would be 4. If you were to set another device to channels 1, 2, or 3, it would receive data from the controller every time you changed the colors on that LED par.

The dmx chain is not a closed loop of cable. It goes from controller, to devices, to the last device and stops with a terminator. It does not need a cable running back to the controller.

Moving lights, foggers, LED lights, etc. also need power, of course. But that power source should NEVER come from a dimmer. It should be a stable source of electricity. The type of things that go into dimmers are par cans, ellipsoidals, crowd blinders, etc.