Thanks. Yes, I have the per-camera zones selected, and motion sensitivity set appropriately. What I'm asking is for a WHOLE-SYSTEM trigger. i.e. When burglar trips cam0: cam0, cam1, cam2, and cam4 ALL start recording, and continue if any or all of them keep sensing motion. Just for configurability, my scenario could have cam3 only trigger itself and cam0 to start recording. Of course, this is just for example. The object is to give the end-user power to configure a system that will function as he wishes. IMHO, triggering the entire setup to start recording is a good idea. I'm just imagining a break in: burglar takes 15seconds to kick in window and climb in, triggering cam0. He then scurries about the place, moving so fast that the normal setup wouldn't trigger any of the other cameras. But if cam0 has triggered them, we would have a complete record of his movements, and more chance of ID'ing the wanker. :-) Obviously, there are lots of uses for surveillance cameras, so this is just one example. Another might be to have a cute record of your dog wandering around the house every time he comes in the dog-flap (trigger), watch as he b-lines for the bed, and get an alert that cam3 (bed-cam) has just caught rover snuggling in under the covers with his pond-water and carrion-rolled-in self.
Thanks for considering. Cheers!