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Syntax for stringCompare of FilteredSummaries

Question asked by Shane318 on Feb 24, 2016
Latest reply on Jun 8, 2016 by pthivierge



When completing a PI AF SDK request in MATLAB I'm having some trouble in defining the stringCompare for FilteredSummaries. I have been able to retrieve data for a simple request such as all values greater than x (i.e. '.'>x), however the string compare I want to make is a little more complicated than this.


I'm looking to count the total number of rising edges for when a PI Point has exceeded the threshold value x.


So far I have defined the following:


import OSIsoft.AF.*
import OSIsoft.AF.Asset.*;
import OSIsoft.AF.Time.*;
import OSIsoft.AF.Data.*;
import OSIsoft.AF.PI.*;

piSystems = OSIsoft.AF.PISystems;
af_server = piSystems.Item(server);
af_database = af_server.Databases.Item(database);
element = af_database.Elements.Item(RootPath);

attribute1 = element.Attributes.Item(attribute);
myPIPoint = char(attribute1.PIPoint.Name);
timeRange = AFTimeRange(starttime,endtime);

StringCompare = = ['''.''','>x',' AND ','PrevVal(','''.''',',','''*''',')<=x']; %StringCompare = '.'>x AND PrevVal('.','*')<=x

AllData =  attribute1.Data.FilteredSummaries(timeRange,AFTimeSpan(timeRange.Span),StringCompare,AFSummaryTypes.All, AFCalculationBasis.EventWeighted,AFSampleType.ExpressionRecordedValues, AFTimeSpan.Zero, AFTimestampCalculation.Auto);

TotalExceedences = AllData.Item(AFSummaryTypes.Count).Item(0).Value;

Based on the results the request is returning, the syntax I have used for PrevVal() is incorrect. Was just wondering if someone can point me to a document that details the correct syntax for this string compare or if they know the correct syntax to use for FilteredSummaries() stringCompare.