A Composite alarm allows users to build a tiered alarm based on several existing alarms. Members of the composite alarm are assigned a priority that affects how simultaneous events are handled. The higher the priority (“1” is highest), the greater precedence will be placed on the alarm. For example, if a Priority 2 alarm is open, then a Priority 1 alarm begins, the composite alarm will end the first event and start a new event. It will also reset the alarm rule. Overlapping alarm events of the same priority will not cause splitting of the composite event.
The deadband, split logic, and uptime settings do not affect composite alarms. The composite alarm will instead respect these settings as configured for its member alarms. For example, if a Priority 1 alarm splits, the composite alarm will also be split.
To add or remove alarms from a composite alarm, expand the Add/Remove Members section. Select alarms in the Available Alarms panel and click Add, or select alarms in the Members panel and click Remove.
Assign a Priority to a member alarm by entering a number in the Priority column. “1” is the highest priority. Multiple member alarms can have the same priority.
The Detection Period affects how far into the past the Alarm Server will look each cycle to assess whether to modify composite events. This is most applicable when using SQC counting rules or when defining alarms for manual entry tags.