2 Replies Latest reply on Aug 7, 2018 7:13 PM by jresnick

    Expression evaluate after Elapsed Time

    KarlRickards

      I'm wanting to build an Expression to be used in an Event Frame but I'm having trouble working out an appropriate expression to evaluate true once all other conditions are met after 5 minutes.  For example, there is a pump that turns on and the effects of that pump running is not seen down stream in the process until approximately 5 minutes later.  Once this time has elapsed and the results of that pump turning on does not deliver the expected variable, that is when I want the Event Frame Triggered.

        • Re: Expression evaluate after Elapsed Time
          sraposo

          Hi Karl,

           

          Can't you trigger on the unexpected values in the variables down stream ? Is this data being captured in PI Points?

           

          Seb

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          • Re: Expression evaluate after Elapsed Time
            jresnick

            Hi Karl,

             

            Not sure if you were able to use Seb's suggestion. If you needed to include the pump's activity in some role, maybe you could try something with the TimeGE function and some logic?

             

            If TimeGE('<Pump Status Attribute>','*-5m','*', "On") = 300 AND <your downstream condition is met> Then 1 Else 0

             

            Note that for this to work, you would need an enumeration set for the Pump Status Attribute to resolve correctly, more information on TimeGE is in the function reference in the PI System Explorer Help Menu.