Thanks for the reply. I emailed Andy at Ultimarc and he's says the only 5v pin is the one with the brown wire, and that it should be OK to power a LED from that. Seems a bit strange though as I read 5v across other pins too, but it's probably best to be on the safe side and just tap into the brown one.
You will read 5v on any encoder input, assuming it is an active-low device like the IPac, KeyWiz, KADE, etc.
Those inputs aren't designed to provide the current required to properly drive an LED.
A quick test on a KADE with a 12v LED revealed:
* Connecting the LED between 5v and ground caused the LED to light brightly
* Connecting the LED between an input and ground triggered the associated output and caused the LED to light very dimly (~10% as bright?)
Scott