The In Maintenance mode is generally employed in the execution of a manual task.

In a typical scenario, a technician might want to effect repairs on a device in the path of a signal being monitored by iControl. Before beginning, the technician would manually set the corresponding alarms to In Maintenance mode, to avoid having iControl report a sudden flood of errors. Once the repairs are done, the technician would then manually take the alarms out of In Maintenance mode, putting them back online, but the alarm latches would not be automatically reset. In this mode, alarm transitions affect the latch and the acknowledgement states of alarms (click HERE).