Splitting the DMX Cat 5 in to branches

[cubbieco]

You are not allowed to view links. Register or Login -  Keeping in mind that the output of the lynx dongle and the DMX spec are only supposed to have 36 units connected without some kind of repeater (like the express if I'm correct) is there anything wrong with using this kind of RJ45 splitter on our lines.  If I understand DMX correctly it is for our purposes basically one way and ever device receives the whole DMX message (packet for lack of a better word) unchanged so this should work.  The only problem I can think of is you'd be losing signal power but this would be for things like an isolated cheapdmx box or something like that.

Am I correct?  And yes I'll find it for cheaper or make it but the radio shack link is a nice picture of a splitter.

Thanks

[pugs1501]

That cat 5 splitter actually splits the 4 pairs of wires into two sets of two pair wires. I am not sure if it would work because I don't know what pairs of wires the DMX dongle sends the DMX information on.

Adam

[rrowan]

What are you trying to accomplish?

Rick R.

[mmciver]

I actually am curious about this also.

When using the little 3 channel DMX controllers they only have one connection for DMX.  I am assuming that you can just tee the cat5 at each interface to create your daisy chain of controllers.

Keeping in mind of course that you have to repeat the signal every so often!

[cubbieco]

Basically I'm integrating some of the cheapdmx controllers for remote locations where a MR16 is impractical.  I'm not wrapping my trees but I think either a rainbow spot or some 5050 LEDs (undecided so far) would look good in them.  The cheapdmx controller doesn't have a DMX out so you'd have to branch it off some how or splice it in.

To answer the other question RJs Lynx dongle uses the white orange wire for DMX + and orange for DMX - (unless I'm mixing the two wires up, it is in the wiki) and he doesn't have a ground.

I probably wouldn't use an off the shelf controller but splice it myself.  I just want to make sure there aren't any consequences I'm not aware of.

[rrowan]

Just my guess.

The lynx controllers have a dmx in and dmx out, they are just tired together so it might work. My concern would be adding noise to the line if those controllers don't have a termination resistor in them. If you get noise than possible false triggering or worse. I don't believe you will cause any damage.

Cheers

Rick R.

(or I could be totally wrong)

[chrisatpsu]

the lynx splitter is also a device that can be used. Since it regenerates the DMX signal, the device limit count restarts on each of the outputs. each splitter has 3 outputs, so you can continue on with you main line, and have 2 branches off for each splitter you use. Plus it's relatively low cost.

[chrisatpsu]

also in thread...
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unless RJ hasnt had time to update his thread, he should still have splitter pcb's available. and you can use more than one.

[taybrynn]

David, thats awesome!