-
Continuous tags have three broad state groups:
-
low (target low to critical low)
-
neutral (between target low and target high)
-
high (target high to critical high)
-
-
The low and high state groups increase in severity from Target, to Standard, and then to Critical.
-
The neutral state closes the open event and clears any alarm state tracking (the excursion delay period starts again when an alarm state is entered).
-
When the tag's state changes from the high state group to the low state group (or low to high), the neutral threshold is crossed. The excursion delay period starts again when the neutral threshold is crossed, whether the neutral state is registered or not (for example, if a tag's state goes from Target High to Target Low or Target High, to OK, and then to Target Low, in both cases the neutral threshold is crossed, and in both cases the excursion delay period starts again when Target Low is registered).
-
The higher levels of severity include the lower levels of severity running in the background (for example, when a tag is in a Critical High state, Standard High and Target High are running in the background. When the tag moves from Critical High to Standard High, Standard High didn't start when the Critical High state stopped, Standard High started when Critical High started or before).
Example one - Baseline
Polling frequency = 1 minute
Excursion delay = 0 minutes (No excursion delay has been configured)
A new event is raised every time the tag's alarm state changes. The open event closes when the tag moves into a neutral state.
Example two
Polling frequency = 1 minute
Excursion delay = 2 minutes
The tag's state needs to remain constant or increase in severity for over two minutes before an event is trigged because the excursion delay is two minutes. In this example, none of the states remain constant or increase in severity for over two minutes, so no event is raised.
The neutral threshold is crossed between Target High and Target Low, so the excursion delay period starts again. The neutral threshold is crossed again from Target Low to Target High.
Example three
Polling frequency = 1 minute
Excursion delay = 2 minutes
Even through the tag's state is Target High from only one minute, the state increases in severity, so a Target High event is raised two minutes after it started. The same applies to Standard High in this example. The open event closes when the tag moves into a neutral state.
Example four
Polling frequency = 1 minute
Excursion delay = 5 minutes
Even through the tag's state is Target High for only two minutes, the state increases in severity, so a Target High event is raised five minutes after it started. The tag's state is Standard High for four minutes, and then decreases in severity. The Standard High state duration doesn't trigger an event because it needs to be constant for over five minutes or increase in severity, so the Target High event remains open.
Example five
Polling frequency = 1 minute
Excursion delay = 5 minutes
Even through the tag's state is Standard High for only two minutes, the state increases in severity, so a Standard High event is raised five minutes after it started. A Critical High event is raised five minutes after the critical state started.
Example six
Polling frequency = 1 minute
Excursion delay = 3 minutes
The Standard High and Critical High events last for three minutes in total. An event is only raised when the event's duration exceeds the excursion delay period (in this example, over three minutes).
The neutral threshold is crossed, so the excursion delay period starts again. The low state increases in severity, so an event is trigged three minutes after it started.
Example seven
Polling frequency = 1 minute
Excursion delay = 5 minutes
The Standard High event is raised five minutes after the Standard High state started.
The Target High state runs in the background during the Standard High state, so when the state changes to Target High, Target High has been running for six minutes in the background already and therefore the excursion delay period has lapsed. The Target High event is raised as soon as the state changes to Target High.
Example eight
Polling frequency = 1 minute
Excursion delay = 2 minutes
Even through the tag's state is Target High for only 1 minute, the state increases in severity, so a Target High event is raised two minutes after it started.
The neutral threshold is crossed between Standard High and Target Low, so the excursion delay period starts again. The low state increases in severity, so a Target Low event is raised two minutes after it started.