CCTV Auto-Iris pin out

[Mark]

Hi,

I have a Tarcus ND-TV-LENS auto-iris and I need to create some
electronics to drive it.

Is there a standard pin out for these type of iris (mine has a 5 pin
din plug)?
I've had a good look round the web and gather that the drive signal is
some sort of video input but as I'm not driving the lens from a video
source can anyone tell me what the video signal looks like?

Thanks,

Mark.