Jamesway Sentry Manual page 123

The machine controller uses the following procedure to determine if there is a turn failure. The rack setup
stored in memory is continually compared to a scan of the racks. If there is a difference and a rack actuator did
not return a signal for the entire 59 minute period (assuming the racks are turned every 60 minutes), the
machine will make a note of that rack but will not yet issue a turn failure. If the rack does not respond again the
next time the rack turns to this position (which is one hour later), then the machine will issue a turn failure
alarm. If that actuator sends back a proper signal this time around, then there will not be an alarm.
The machine state screen will always show the number of racks currently scanned by the machine. Even if this
number goes below the number of racks programmed there may not be an alarm because the machine has to
see a failure twice before issuing an alarm. This is also why there is no alarm when the racks are leveled. The
machine state screen will say Racks detected: 0, but if the racks are placed back in the machine before 2 turn
cycles have taken place, there will not be an alarm.
Sentry Control System 123