Annex A (informative) Aggregate Specific examples – Historical Access ToC Previous

A.1 Historical Aggregate specific characteristics ToC Previous Next

A.1.4 Example Aggregate data – Historian 4 ToC Previous Next

This example is included to illustrate Boolean data. For the purposes of Historian 4 examples consider a source historian with the following data:

Timestamp Value StatusCode Notes
12:00:00 - Bad_NoData First archive entry, Point created
12:00:02 TRUE Raw, Good  
12:00:25 FALSE Raw, Good  
12:00:28 TRUE Raw, Good  
12:00:39 TRUE Raw, Good  
12:00:42 - Raw, Bad Bad quality data received, Bad data entered
12:00:48 TRUE Raw, Good Received Good StatusCode value
12:00:52 FALSE Raw, Good  
12:01:12 FALSE Raw, Good  
12:01:17 TRUE Raw, Uncertain Value is flagged as questionable
12:01:23 TRUE Raw, Good  
12:01:26 FALSE Raw, Good  
12:01:30 TRUE Raw, Good  
  - No Data No more entries, awaiting next Value

For the purposes of all Historian 4 examples:

  1. TreatUncertainAsBad = True. Therefore Uncertain values are treated as Bad, and not included in the Aggregate call.
  2. Stepped Attribute = True. Therefore SteppedInterpolation is used between data points.
  3. UseSlopedExtrapolation = False. Therefore SteppedExtrapolation is used at end boundary conditions.
  4. PercentGood = 100, PercentBad = 100. For Boolean data interpolation and extrapolation shall always be stepped.

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