Doors, windows, cabinets, electrical panels, the drawer with the documents in it. Each reports the moment it opens — and an opening that is routine at noon is an event at three in the morning.
Motion in a restricted zone, or in any zone at an hour when nobody should be there. Indoors and out in the yard, where the expensive things usually sit and the watching usually doesn't.
A sensor notices the first millimetre, long before anything leaves the room. The same one catches a hard knock: a dropped crane remote is logged, not found by the next shift.
Equipment that starts or stops when nobody scheduled it. A machine running at midnight, a freezer switched off on Friday evening — the same kind of event, and it reaches you while it is still true.
A loose terminal or a failing contact warms up for hours before anything burns. It happens inside a closed cabinet, where a ceiling detector cannot see it and nobody opens the door until the next inspection.
Electrical panels and switchgear. Battery charging areas. Server and control cabinets. Sealed enclosures outdoors. Anywhere the temperature has a normal range and nobody is watching it.
A camera tells you what happened. It does not tell you that it is happening
Footage answers questions you ask after the loss. Nobody watches thirty screens at three in the morning — the recording gets opened the next day, once somebody notices that something is gone.
Alarms cover the doors while the building is empty. It has nothing to say about a cabinet opened during the shift, a machine moved across the yard, or a panel warming up behind a closed door.
An alarm is armed or disarmed as a whole. Here each door, cabinet and machine keeps its own schedule — what is routine on a Tuesday shift is an event on Sunday night.