dmx connection

[The Boogie Man]

Ok feel free to shout at me, I'm sure this must have been covered here somewhere. I looked in the faq at the top of the page but couldn't see anything.

 

Looking at a lighting desk ( the behringer In this case) I noticed it has only 1 output marked 512dmx. and led lights hav a DMX in and out.

 

Do the lights just daisy chain?

baz

[Oovis]

Quick answer; Yes, normally.

 

You can daisy chain them together, then in the final unit you need a terminator. This is a 5pin XLR with a 120 ohm resistor soldered between pins 2 & 3. This soaks up the signal to stop reflections back down the line, which would cause problems.

[The Boogie Man]

Cheers oovis,

 

So do things that require different instructions ( moving lights) have to leave the desk on different outputs then. Is this what I've heard called universes or is that something different again?

[soundo26]

Cheers oovis,

 

So do things that require different instructions ( moving lights) have to leave the desk on different outputs then. Is this what I've heard called universes or is that something different again?

 

The DMX output comes out of the desk and usually goes to the first dimmer rack, all DMX fixtures have inputs & outputs. The signal will come out of the dimmers to the fist fixture and so on until you get to the last which should be terminated with a termination plug which is fitted to the output socket of the last fixture in line. The DMX signal should not be split unless you are using a proper buffered Splitter.

 

Each DMX unit including the dimmers have to be addressed either by dip switches or vai the fixture's menu system. The address of your fist dimmer will be 001, if it has six channels, the next available address will be 007, this address you will assign to the next fixture and so on (you will need to know how many channels are needed for each fixture). If you are using intelligent moving fixtures they will probably be using about 16 channels each, basic disco type moving mirror scans may only use 4-6.

 

If you are short on channels but want, say, four fixtures to do the same thing, you may address those four fixtures to the same address, if you are using two left and two right and want them to pan the opposite way to each other you may be able to still do this but reverse the pan setting on the fixture itself.

 

Hope this helps!!!!!

[pritch]

So do things that require different instructions ( moving lights) have to leave the desk on different outputs then. Is this what I've heard called universes or is that something different again?

 

Nope.

 

Basically, a DMX Universe can control 512 DMX addresses / channels.

 

In the case of a single channel dimmer, it will use up one DMX address, to control the brightness.

 

In the case of a moving light, you would end up using several different DMX addresses, one for brightness, two for position, one (or more) for colour, one (or more) for beamshape and whatever else that fixture has that can be changed.

 

However, you can still daisy chain. Your one desk output will control any combination of fixtures up to 512 channels (or a lower figure if the desk doesn't support controlling that many channels).

 

Larger desks for larger setups will control more than one universe, but all this means in practice is that you can control a larger number of fixtures.

 

Edit: Must type faster

[The Boogie Man]

cheers guys,

 

So each "intruction to a light ( moveleft, get brighter,etc) is on an individual channel?

 

a par 64 led would require how many cannels then?

 

baz

[pritch]

Depends on what exactly said LED lantern will do.

 

If it's single colour, then it'll probably be one channel, for brightness only.

Cheaper RGB LED lamps will take three channels, one for red brightness, one for green brightness, one for blue brightness.

A more expensive RGB LED will take the three for the colour mix, and add a fourth which controls the overall brightness.

 

If you look in the specs / manual of the fixture, it'll tell you how many channels you need. You'll set the first DMX address, and the others will go on top of that.

[paulears]

annoyingly, 4 or 5. 1 does overall brightness, 3 more do blue gren and red, and the other depending on type does things like turn on auto chase, and other cleverer things