1 Reply Latest reply on Nov 19, 2017 6:50 PM by John Messinger

    Retrieve tags with 1ms time difference

    gcampbell

      Hello all,

       

      I am extracting data into excel from 'Tag1' using datalink by using PICompData.  I am then getting the value of several other tags by using PIArcVal for each timestamp generated.

       

      Each of these tags always has data generated at the same time, and are scanned at 1 second intervals, however occasionally I don't get a value returned for the other tags.

       

      Having looked into it further, it appears that occasionally the other tags have a timestamp that is offset by +/- 1 ms.

       

      Is there an obvious solution to this issue, where I can get data without being affected by this micro time offset?

        • Re: Retrieve tags with 1ms time difference
          John Messinger

          Hi Graeme,

           

          What retrieval mode are you using with your PIArcVal() function call? It sounds like you could be using 'exact time' as you are expecting values to line up at the same timestamp. If you use the default option of 'auto', does the interpolated result match what you are expecting to see? Related to that, do any of these related tags have the step attribute tuned on?

           

          John

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