I am trying to develop a script that recognizes when an iPad is done with its iTunes synchronization and backup, so that it forces a user logoff. We're going to be using one workstation for backing up several iPads and we'd like to keep each user's backups in their own account.

I've identified a process, AppleMobileBackup, which ends when the backup is over. I thought I would have similar luck with SyncServer for synchronization, but that process does not end when the synch is over, nor when iTunes is closed, nor even when the iPad is disconnected to the USB port.

Is there some other way I can identify when an iPad is no longer connected to a PC?