what software are you using? or are you just viewing on the tv? If your using AHP then set your motion sensors to a different house code than your cameras.
then setup macros for recording. example: motion sensor for cam 1 is m1, motion sensor for cam 2 is m3 (the reason to skip numbers is as Puck said, it fires unit code +1. sooo m1 will fire m1, m2)
cameras set to cam 1 is c1, cam 2 is c2, cam 3 is c3, cam 4 is c4 and so on.
then setup a macro with the trigger m1, select camera c1, record video, delay 1 min (or however long you want the recording to be), stop recording.
there are tons of information in these forums for cameras, motion sensors, recording. Do a search and find a wealth of information. hope this helps!