5 pin DMX- 512 channels... or 1024?

[Mayhem]

I actually don't use scrollers but the cable used for power was a heavier gauge. As you correctly point out - normal data cable would soon heat up and cause problems due to resistance.

Glad that I never actually used them as I hear the cables are a bitch to make. Especially given the lack of space in a 5pin connector.

 

[ship]

Not even easy to make them with four pin connectors.

 

[MSwan]

You could if you had the need make use of both pairs in true 5pin (I say 'true 5pin' as I have found cables with 5 pin connectors and only one twisted pair) to send 2 universes. Let's say your console is a 200' run away from your dimmers and/or moving lights. You could build an adapter for each end, both would need 3 5pin connectors:
side 1
connector A: plugged into universe 1
pins 1-3 as normal, pins 4&5 not connected
connector B: plugged into universe 2
pins 1-3 as normal, pins 4&5 not connected
connector C: plugged into cable to stage (or whereever)
pin 1 shield from both connector A & B
pins 2&3 connector A pins 2&3
pins 4&5 connector B pins 2&3
side 2
connector D: from the booth
pin 1 split to connector E & F pin 1
pins 2&3 to connector E pins 2&3
pins 4&5 to connector F pins 2&3
connector E:
pins 1-3 as normal, pins 4&5 not connected
connector F;
pins 1-3 as normal, pins 4&5 not connected

This would in theory work I am not sure if I would ever do it and I would never do it for 2 different boards. As long as both universes are coming from the same board they are grounded togther already. All this would really do is save you some cable. I have seen at least one company use cable with even more data pairs in it and run 4 - 6 universes through it.