Historian SDK

First Property

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First Property

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Last UpdatedAug 21, 2026
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HMI and SCADA
Historian

Gets or sets the first point stored with a timestamp within the retrieval cycle, if at least one non-NULL point exists for the tag within the retrieval cycle.

Syntax

'Declaration
 
Public Property First As Double

'Usage
 
Dim instance As AnalogSummaryQueryResult
Dim value As Double
 
instance.First = value
 
value = instance.First

public double First {get; set;}

public:
property double First {
   double get();
   void set (    double value);
}

Property Value

If no points exist within the retrieval cycle, then the value returned is the current value at the cycle start time. If no non-NULL points can be found, then NULL is returned. If the first value is NULL, then it is represented by NaN.

Historian SDK

First Property

Table of Contents

First Property

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Historian SDK

First Property

Syntax

Property Value

Requirements

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Reference

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