I am trying to take a sum of a few live PI Tags that read out a tank volume (m3), and then build a PI Calc that reads out the present value minus the previous hour value in order to give me a rate of change (i.e. m3/hr). Does anyone know how I could build a new PICalc tag to do this in PI Processbook?

Thanks for any and all help!

I believe that you can build the sum with the PI Calc feature in ProcessBook, but I do not think it is possible to build your rate of change with PI Calc since the PI Calc dataset is restricted to just displaying live values.

Would it be possible for you to create a performance equation to perform this on the PI Server side or use Analytics? Once this is done, you can then pull the value of the tag directly into ProcessBook and you will not have to use the PI Calc data set.