Has anyone had experience with using AF to monitor control loops?
Brian: It is straight forward to do basic control loop monitoring stats and alerts... see AF example below.
Thank you very much Gopal!
Brian Bolton, OSIsoft PI Suite of Applications
Eastern Standard Time (UTC-5)
I would do this differently. We have been grouping the loop's attributes under one attribute like this:
Top (parent) attribute: Process variable
loop parameters (P, I, and D gains/constants)
some even have some loop monitoring solutions and statistics under here, so we put those attributes here too
If I was building a loop monitoring solution, I would probably build an element (from a template) for each loop and group all loops per plant area under its own hierarchy level. That way, I could do collections on the loops based on what I want to see (i.e. ones in manual, ones that have significant deviations like Gopal shows above, etc.).
Typically, we have been putting all of the loop attributes under their appropriate equipment elements (i.e. the pressure and level controller loop attributes would be inside a tank element), but we have had at least cursory discussions with several customers about another, more flattened structure just to do loop monitoring. In that case, we would do 1 template/element per loop, and not put it under a higher level element.
We like to group all of the loop parameters in one set of attributes, rather than scatter them as above. We have done this for numerous customers and they seem to like it.
Great, thank you Jim.
Thank you Roger
May i know how you derived variability % ?
I assume that's the plain difference between the setpoint and the process variable expressed in a percentage. That's likely looking at the numbers in the example shown.
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