back up camera?

Has anyone used a back up camera that is linked to an aftermarket headunit. I just purchased a new unit that has an video input for the camera and has a "Backsight Camera Control Line" coming off the radio harness. I need to know how to hook this up the best way, so that the camera will turn on and pop up on the screen while in reverse. Don't really want to add a seperate swith for this..

I think hook it to one of my reverse wires in the tail lights.

I've never heard it called that....most of the time it says "reverse wire".  I'm guessing it's the same thing....but we need your year/make/model of vehicle, and maybe the unit being installed. 

And yes, hooking it to the reverse lights is the way, but we need the vehicle so we can get you the right info!!