About continuous execution - alarm aggregation

With alarm aggregation enabled on the Area object (AlarmAggregationStateCmd value is True), the Area counts all alarms on the area at each scan cycle, and aggregates their status values as follows:

• The Area aggregates alarm status information from all alarms on the Area itself, on all Objects and their descendants assigned to the Area, and on all sub-Areas of the Area and their descendants.

• The Area aggregates alarm statuses from all child sub-Areas one hierarchical level downward in the model view. The sub-Area aggregation values are added to those of the parent Area. Each sub-Area aggregates alarm statuses from any child sub-Areas one hierarchical level downward. The end result is alarm status information aggregated on the Area itself, on all assigned Objects and their descendants, and on all sub-Areas and their descendants.

• The Area checks if the alarm status values aggregated on a sub-Area are more urgent than alarm status values aggregated on the Area itself. If so, the Area updates its own alarm aggregation status values to those of the sub-Area. Otherwise, the Area aggregation status values are unchanged.

• The Area adds the sub-Areas’ AlarmCntsBySeverity to its own regardless of relative alarm status urgency.

A sub-Area’s alarm status values can be more urgent than the parent Area’s if:

• No alarms have been aggregated on the parent Area.

• AlarmMostUrgentMode of the parent Area is silenced, but that of the sub-Area is enabled.

• AlarmMostUrgentInAlarm of the parent Area is false, but that of the sub-Area is true.

• AlarmMostUrgentAcked of the parent Area is true, but that of the sub-Area is false.

• AlarmMostUrgentSeverity of the parent Area is lower (represented by a higher integer 1-4) than that of the sub-Area.

Pseudo Areas behave like Areas in how they report alarm statuses both in the Distributed Alarm System and in Alarm Aggregation. Pseudo Areas include the WinPlatform Object and Device Integration Objects such as the OPCClient Object and the DDESuiteLinkClient Object. Alarm Aggregation cannot be disabled on pseudo Areas.