Control Record Time

In the monitor setup under the Buffers section, you'll want to put the Post 
Event Image Count to the number of Frames to record after no motion is detected.
I.E. If you're recording at 10 FPS and you want to record for 30 seconds after
the last motion is detected then you would put in 300 (10 x 30).

To limit the max recording size to 5 minutes you'll want to go into the Misc 
section of the monitor setup and adjust the section length. This will limit 
video clips to that length.