Alarm Limits have to be defined in the imported Loop Check Settings. Undefined Alarm Limits are skipped.
Field Information Manager supports the Alarm Limits High-High (HH), High (H), Low (L) and Low-Low (LL). An alarm is verified by the corresponding alarm event in the System Event List which is identified by the condition name. Each of them is tested in hysteresis to ensure a correct alarm behavior, resulting in 3 test points for each alarm:
- No Coming Alarm: Passed if no event with status indicated "New" and matching condition is raised in System Event List.
- Coming Alarm: Passed if an event with status indication "New" and matching condition is raised in System Event List.
- Going Alarm: Passed if an event with status indication "Inactive" and matching condition is raised in System Event List.
A failed test point indicates a mismatch of the Alarm Limit configurations in System (used for alarm event generation) and imported Loop Check Settings (used during Loop Check).
In order to recognize a detected alarm event, the status indication, timestamp, condition and message are copied from System Event List to Loop Check Details and Reports.
For correct detection of alarm events with their timestamp, the Field Information Manager client and system connectivity node must be synchronized with regards to time.
In order to ensure a correct alarm and event sequence, existing alarms for the corresponding node are acknowledged automatically before, during and after execution of Loop Check.