The event occurrence period applies to access control units and intrusion detection units that were temporarily offline. If a unit is offline in Security Center, but still physically running, when the unit is re-connected the events that were stored on the unit while it was offline are received in Security Desk. The occurrence period value indicates how long ago the event occurred before the unit came back online, and determines what happens when the event is received.
Only certain types of units (for example, HID VertX units) keep a record of events that occur while it is offline.
The four event occurrence values are listed below, with a description of what happens when Security Center receives the event:
- The event occurred when the unit was online.
- Grace period
- The event occurred less than 15 minutes before the unit came back online. Security Center treats the event as a normal event. It appears in the event list in the Monitoring task. Actions that are associated with the event using event-to-actions are triggered.
- Alarm grace period
- The event occurred in between 16 minutes and 72 hours before the unit came back online. When the event is received in Security Center, it does not appear in the event list in the Monitoring task. The only actions that are triggered using event-to-actions are Trigger alarm and Add bookmark. The event is recorded in the database and is available for reporting.
- Pre-alarm offline period
- The event occurred more than 72 hours before the unit came back online. When the event is received in Security Center, it is only recorded in the database for reporting.
Reasons why units can be offline
- The unit is rebooting.
- The unit’s firmware is being upgraded.
- The connection between the unit and the Access Manager or Intrusion Manager is lost.
- The connection between the Access Manager or the Intrusion Manager and the Directory is lost. When this happens, the role disconnects from its units until the connection with the Directory is re-established.