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 43.

Table 43 – 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 44.

Table 44 – 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.