1 Reply Latest reply on Jan 21, 2018 2:40 PM by asaleh

    Summing up ramping data that resets in long time period


      Hi all,


      I would be grateful if someone has simple automatic method for summing up ramping data (pump running hours) that resets periodically.


      Data trend looks like this:

      Where on x axis is time and on y axis is summarized running time.

      I would like to summarize all peak data and latest accumulation in excel and preferably later on in PE, Totalizer or Analysis to track running hours.


      Data could be:

      • for past 5 years
      • starting at some point
      • ending at some point
      • reset as some point



      1. What is the easiest way to summarize data for one time analysis?
      2. What is best practice to accumulate past data and continue accumulating in real-time?






        • Re: Summing up ramping data that resets in long time period

          Hello Sregej .. Thanks for posting on PI Square .. our community !


          The difficult part about your request is how to detect the peak. I am not sure how your data set looks like, but according to the example, the criteria of determining a peak of 'y' is the following :


          1- y is greater than 0 or any reasonable value.

          2- y stabilizes for certain time 'x'.


          So what you can do is to implement PI Asset Analytics to store 'y-value' when it did not change for a specified time interval 'x minutes'. Please refer to Expression functions reference to see the available expression functions and their syntax.


          For instance, in your case:


          1- You can check if the value is changed or no using 'haschanged' function and specify the 'x minutes' to consider a peak situation. If the answer is false, then this is a peak.

          2- You can use an if statement to check if the value is greater than 0 and the peak flag is false. If the condition is valid it stores the 'y_Value"

          3- You can use the 'TagTot' function to sum all the stored "Y_values" when the peak condition is valid.


          The same idea can be achieved by using performance equations. But Asset Analytics will not consume a PI Tag if you are not historizing the results and you can back-fill it to cover any time interval in the past (Which answers your second question).


          Please let me know if you have further questions regarding this !