6 Replies Latest reply on Apr 15, 2019 4:35 PM by sgujje

    Unwanted compression and interpolation of data




      We are using PI System to store packed column volumes data. Each column gets packed only once in 2-3 months and the value stays same for that period. However, when it gets a new value after 3 months, PI tend to give the interpolated data when searched in between the time periods which is not desirable. Detailed explanation below,

      Column volume PI Tag: Column_Volume_CV,    Packed column volume real data,   01Jan2019 to 30Mar2019, value is 30 liters     30Mar2019 to current, value is 45 liters.

      While doing the sampled data query, between 29Mar2019 to 01Apr2019, values are interpolated which it should not be.

      Time               Column_Volume_CV

      29Mar19        30

      --                    34   (Where the real value is 30)

      --                    37

      --                     41

      --                     43     (Where the real value is 30)

      30Mar19         45

      01Apr19          45


      What are the ideal compression and exception settings of these tags on OSI Pi, so that the values stay real during the change of data