AnsweredAssumed Answered

PI Interpolating Data Unexpectedly

Question asked by Greg_C on Feb 23, 2019
Latest reply on Feb 27, 2019 by JaisonRodrigues

First off, I'm not a PI user, so please excuse my ignorance.

I'm a user of PI data through Excel 2016. (PI-SDK 1.3.8)



I'm having an issue with numerous tags where Citect is recording data correctly, but PI is making unexpected linear interpolations.

It seems that if the value is constant for too long, PI stops recording it, and instead interpolates to the next significantly different value.

Attached is an output from Citect, and a plot of the PI data for the same ~3 hour time frame.

Note the Citect sample rate in this example is 5 seconds, and PI is 60 seconds.



Hopefully someone has seen this before and can suggest a solution which I can pass onto my IT department?