4 Replies Latest reply on Jul 30, 2013 2:00 PM by Marcos Vainer Loeff

    PI Totalizer recalculation

    Bannikov

      Hello!

       

      We've such issue. We're using ACE to perform some calculations that're stored in PI Tag. This tag act as source tag for Totalizer point which produces per day statistics.

       

      Sometime our ACE fails for some reasons. After we restart ACE, it continues to write data to PI Tag. Then we can recalculate tag data for downtime period using ACE Manage Recalculate feature. But we can't recalculate associated Totalizer point. What can be done about this? Maybe somebody can give me an advice about this situation...

        • Re: PI Totalizer recalculation
          mhalhead

          Hi Sergey,

           

          Bluntly there is no easy way to recalculate a totalizer. The only option is to do a manual recalculation offline (i.e. using another tool like Excel or a custom program) and then push the "recalculated" results back into PI. FYI, the reason that there is no recalculation option on totalizers is because totalizers run of the snapshot subsystem not the archives. Therefore, the data isn't available after the fact. This is done to ensure that the totalized values are more accurate.

            • Re: PI Totalizer recalculation

              Hello Sergey,

               

              How about moving the calculations currently performed by Totalizer subsystem into the ACE calculations? For sure you will have to ensure calculations also work when using ACE Recalculator but to me this appears to be the best solution because you can achieve the same level of accuracy and reduce the maintenance effort to just recalculating ACE modules.

              • Re: PI Totalizer recalculation
                Marcos Vainer Loeff

                Hello Sergey,

                 

                I could think of two solutions to your problem:

                 

                1) Try to convert your totalizer tag to PI Performance Equation point and then you will be able to use pirecalc to recalculate. This is possible depending on the settings of your calculation, but it is worth checking this possibility even not using snapshot values on the calculation. Remember that pirecalc will recalculate the values that already exist on the PI Server. It won’t create any new value.

                 

                2) Create a custom PI AF SDK console application.

                 

                There is a possibility to use also PI ACE, but I need to investigate how this would be done. However, I personally would choose the second option in order to have more control of the application.

                 

                Let me know if you still have any question,