Just to confuse things a bit...
I run +12V DC over cat5 for my DMX elements. It allows me to inject power into the cat5 and then have a chain of DMX elements that draw from that power.
The AetherII needs 12V AC (not DC).
I mention this because -- inside the junction box on the AetherII enclosure I connect wires that carry the +12V DC/Ground from the input pigtail to the output pigtail. The AetherII does NOT tap into the DC power, but it will propagate the power for the next element to use in the chain of DMX devices.
What does this buy you? It allows me to create a series that looks like this:
dongle, 12V DC injector, DMX star, AetherII, DMX star, DMX star, AetherII, DMX star, DMX star...
... 12V DC injector, DMX star, AetherII, DMX star, DMX star, AetherII, DMX star, DMX star...
In other words, I don't let the AetherII interrupt the power being passed along my powered-DMX cable.
I often do this for other DMX elements, not just AetherII. (MR16, LE, etc.)