I had the tally wired on my DP 7. I can't remember how I did it, but It has to go through the composite video connection on the side of the monitor. This is difficult if you have a yolk because there is usually very little clearance between the monitor and the yolk. You need a right angle Hirose, and I don't think they make one. The tally lights are located on the back of the monitor so you can't even see them when they are lit. On top of that, the DP7 2.0.4 software upgrade disables the composite connection . I called Small HD about this and they said they were going to fix it. That was at least a year ago. I can't remember if it disables the tally, but since I couldn't see it anyway, I ended up getting the Zalex Tally from Peter Abraham. I am happy with the Zalex.
Colin