We have set up some event frames to monitor product quality. When a specification is exceeded, we trigger an event frame. When the quality returns below the limit, the EndTrigger triggers to close it. However, we sometimes find that we get multiple event frames generated in a short period, because the quality drops below then goes back above the limit several times over a few minutes. In these cases, we only want a single event frame to be generated.
There is not a "True For" on the end trigger like there is on the start trigger. So to handle this, I was thinking I coudl create a Duration variable:
Duration = EventFrame("Duration")
I could then modify the EndTrigger to test the duration:
EndTrigger = ('QualityValue' < 'Quality Limit') AND (Second(Duration) > 300)
Should this work? I am concerned that it may prevent the event frame from closing, but it wouldn't stop another event frame being generated when the start trigger is breached. I don't want to set a "True For" limit on the start trigger, because we do need to report every excursion.