Have time series charts that compare values from a historian tag to a setpoint, and then displays segments of 2 minutes where the value is above setpoint as green and values below as red. With much much help from this forum it is working essentially as intended, however one unforeseen consequence of using the history enabled tag is that whenever the operator changes the setpoint, the chart will sort of "back update" and change the display to match if the Old value was above or below the New setpoint. Is there any way to make the chart only look at the most recent value in the historian tag and sort of "record" that, only clearing / resetting after say 24 hours?
Sounds like you need to historize your setpoint, too, then use its history in your comparisons.
No, you'd have to bind that setpoint to a memory tag, and historize that.
This is the custom binding for the setpoint:
The tag referenced here ^ does have history enabled
This is how it is referenced in the chart:
Is there a simple way to make this reference the historicized info?
Not really. You have to query history for both tags, then transform to produce process value and error value at each process value timestamp, then color each point (or split into the separately colored pens).
It currently has two different pens already, as far as the rest of it though it sounds very beyond me, thank you for your time and consideration though.
or do you have any resources for querying history and the other necessary knowledge for this route?
Presumably you have a history query already, for the process value. You would add to that query to also return the setpoint history.
Yes. But on this forum, in public, I generally coach rather than do, unless the task is uniquely interesting and I have time. That produces, in my opinion, the most value for participants, lurkers, and future visitor searches.
I'm an integrator--I'm always interested in offering my professional services to those not willing to be coached. Contact me privately to go that route.
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