Like I had stated before, since the motion detection on the current out of the box security cameras can not tie back into the system this is not a feasible option for us. We need the nurse call system to trigger the camera so that we have the record of the movement in the room.
So the idea is that the relay signal means "take some pictures" and you want your solution to write a sequence of pictures to a file server somewhere? Well the easy solution would be Arduino, gobetweeno and a PC with a webcam and freeware to take pictures on demand. Does the relay have to be in the room you're trying to photograph? If not, wireless web cams controlled by a central PC would be one possible solution. Otherwise, I suppose you could bring the relay signal back to the PC using an Arduino and radio and otherwise use the same solution. The hardware cost is starting to add up, though.