liam1
January 9, 2025, 2:34pm
1
Hi all,
I want to setup an alarm that will trigger when a process value has been out of range accumulatively for more than a set percentage of an hour. Note the hour window is also moving
Here is an example
What would be the simplest way of implementing this?
Thanks,
Sounds like you need to historize this tag and run a tag history query to get your accumulation.
Yeah, I don't think there is any "simple" way to do this.
Maybe:
create a boolean expression tag that is true when the process value is >= limit, false otherwise
historize this expression tag
periodically (timer script?) run a tag history query on this tag, using aggregation mode duration on (or duration off if you flip the logic)
if the duration on > 40% of an hour, set another boolean memory tag on which you've defined an alarm
2 Likes
He might can combine the alarm boolean expression with a transaction group hour meter?
Hour and Event Meters | Ignition User Manual