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6.2 OPC UA ObjectTypes ToC Previous Next

6.2.3 IRollingStatisticsType ToC Previous Next index

The IRollingStatisticsType is a subtype of the IStatisticsType Interface. The statistical data managed by Objects or ObjectTypes implementing this Interface is rolling over, i.e. only a certain amount of data is considered for statistical data. It is formally defined in Table 40.

Table 40 – IRollingStatisticsType Definition

Attribute Value        
BrowseName IRollingStatisticsType        
IsAbstract True        
Description Base interface for managing statistical data that is rolled over, i.e. only a certain amount of data is considered for statistical data.        
References Node Class BrowseName DataType TypeDefinition Other
Subtype of the IStatisticsType defined in 6.2.1, i.e. inheriting the InstanceDeclarations of that Node.          
0:HasProperty Variable WindowDuration 0:Duration 0:PropertyType O
0:HasProperty Variable WindowNumberOfValues 0:UInt32 0:PropertyType O

WindowDuration describes the duration after the statistical data are rolled over. Only the data that were gathered during that duration are considered for the statistical data, even if the time intervals between the StartTime and the current time is longer.

WindowNumberOfValues describes the maximum number of values before the data gets rolled over. For the statistical data, only the data fitting into the number of values is considered, even if more data were gathered since StartTime.

An Object or ObjectType implementing IRollingStatisticsType shall never provide WindowDuration and WindowNumberOfValues together It shall provide a maximum of one of those Properties.

The InstanceDeclarations of the IRollingStatisticsType have the Attribute values defined in Table 41.

Table 41 – IRollingStatisticsType Attribute values for child Nodes

Source Path Value Description
WindowDuration - The duration after the statistical data are rolled over. Only the data that were gathered during that duration are considered for the statistical data, even if the time intervals between the StartTime and the current time is longer.
WindowNumberOfValues - The number of values before the data gets rolled over. For the statistical data, only the data fitting into the number of values is considered, even if more data were gathered since StartTime.

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