4 Aggregate Information Model ToC Previous Next

4.2 Aggregate Objects ToC Previous Next

4.2.2 AggregateFunction Object ToC Previous Next

4.2.2.1 General ToC

This Object is used as the browse entry point for information about the Aggregates supported by a Server. The content of this Object is already defined by its type definition. All Instances of the FolderType use the standard BrowseName of ‘AggregateFunctions’. The HasComponent Reference is used to relate a ServerCapabilities Object and/or any HistoricalServerCapabilities Object to an AggregateFunction Object. AggregateFunctions is formally defined in Table 3.

Table 3 – Aggregate Functions Definition

Attribute Value        
BrowseName AggregateFunctions        
References Node
Class		 BrowseName DataType TypeDefinition ModellingRule
HasTypeDefinition Object
Type		 FolderType Defined in OPC 10000-5    

Each ServerCapabilities and HistoricalServerCapabilities Object shall reference an AggregateFunction Object. In addition, each HistoricalConfiguration Object belonging to a HistoricalDataNode may reference an AggregateFunction Object using the HasComponent Reference.

4.2.2.2 AggregateFunctionType ToC Model

This ObjectType defines an Aggregate supported by a UA Server. This Object is formally defined in Table 4.

Table 4 – AggregateFunctionType Definition

Attribute Value        
BrowseName AggregateFunctionType        
IsAbstract False        
References Node
Class		 BrowseName DataType Type Definition Mod. Rule
Subtype of the BaseObjectType defined in OPC 10000-5          

For the AggregateFunctionType, the Description Attribute (inherited from the Base NodeClass), is mandatory. The Description Attribute provides a localized description of the Aggregate.

Table 5 specifies the BrowseName and Description Attributes for the standard Aggregate Objects. The description is the localized “en” text. For other locales it shall be translated.

Table 5 – Standard AggregateType Nodes

BrowseName Description
  Interpolation Aggregate
Interpolative At the beginning of each interval, retrieve the calculated value from the data points on either side of the requested timestamp.
Average Retrieve the average value of the data over the interval.
TimeAverage Retrieve the time weighted average data over the interval using Interpolated Bounding Values.
TimeAverage2 Retrieve the time weighted average data over the interval using Simple Bounding Values.
Total Retrieve the total (time integral) of the data over the interval using Interpolated Bounding Values.
Total2 Retrieve the total (time integral) of the data over the interval using Simple Bounding Values.
Minimum Retrieve the minimum raw value in the interval with the timestamp of the start of the interval.
Maximum Retrieve the maximum raw value in the interval with the timestamp of the start of the interval.
MinimumActualTime Retrieve the minimum value in the interval and the timestamp of the minimum value.
MaximumActualTime Retrieve the maximum value in the interval and the timestamp of the maximum value.
Range Retrieve the difference between the minimum and maximum value over the interval.
Minimum2 Retrieve the minimum value in the interval including the Simple Bounding Values.
Maximum2 Retrieve the maximum value in the interval including the Simple Bounding Values.
MinimumActualTime2 Retrieve the minimum value with the actual timestamp including the Simple Bounding Values.
MaximumActualTime2 Retrieve the maximum value with the actual timestamp including the Simple Bounding Values.
Range2 Retrieve the difference between the Minimum2 and Maximum2 value over the interval.
Count Retrieve the number of raw values over the interval.
DurationInStateZero Retrieve the time a Boolean or numeric was in a zero state using Simple Bounding Values.
DurationInStateNonZero Retrieve the time a Boolean or numeric was in a non-zero state using Simple Bounding Values.
NumberOfTransitions Retrieve the number of changes between zero and non-zero that a Boolean or numeric value experienced in the interval.
Start Retrieve the value at the beginning of the interval.
End Retrieve the value at the end of the interval.
Delta Retrieve the difference between the Start and End value in the interval.
StartBound Retrieve the value at the beginning of the interval using Simple Bounding Values.
EndBound Retrieve the value at the end of the interval using Simple Bounding Values.
DeltaBounds Retrieve the difference between the StartBound and EndBound value in the interval using Simple Bounding Values.
DurationGood Retrieve the total duration of time in the interval during which the data is Good.
DurationBad Retrieve the total duration of time in the interval during which the data is Bad.
PercentGood Retrieve the percentage of data (0 to 100) in the interval which has Good StatusCode.
PercentBad Retrieve the percentage of data (0 to 100) in the interval which has Bad StatusCode.
WorstQuality Retrieve the worst StatusCode of data in the interval.
WorstQuality2 Retrieve the worst StatusCode of data in the interval including the Simple Bounding Values.
AnnotationCount Retrieve the number of Annotations in the interval (applies to Historical Aggregates only).
StandardDeviationSample Retrieve the standard deviation for the interval for a sample of the population (n-1).
VarianceSample Retrieve the variance for the interval as calculated by the StandardDeviationSample.
StandardDeviation Population Retrieve the standard deviation for the interval for a complete population (n) which includes Simple Bounding Values.
VariancePopulation Retrieve the variance for the interval as calculated by the StandardDeviationPopulation which includes Simple Bounding Values.

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