Accumulator variable properties

AccumulatorResetPoint

The calculation behavior after a negative transition, as as NegativeTransition or as a DefinedResetValue.

The accumulator is reset to zero on a negative transition greater than the defined AccumulatorThreshold value.

Options

• NegativeTransition - If the AccumulatorResetPoint is set to NegativeTransition, then on a negative transition the CalculatedSample value is calculated as the difference between the sample from the last polling interval and the value prior to the negative transition plus the sample at the current polling interval.

• DefinedResetValue - If the AccumulatorResetPoint is set to DefinedResetValue, then on a negative transition the CalculatedSample value is calculated as the difference between the value from the last polling interval and the AccumulatorResetPoint value plus the sample for the current polling interval.

NegativeTransition, DefinedResetValue

AccumulatorResetValue

The property specifies the value at which the accumulator resets.

This property becomes available when the AccumulatorResetPoint is set to DefinedResetValue.

Any positive numeric type, depending on the value of the current Data Type

AccumulatorThreshold

A fluctuation threshold for difference in values. If the difference between the current value of a tag and the value of the tag when AVEVA™ Production Management created the last record is less than the AccumulatorThreshold value, AVEVA™ Production Management treats the difference as zero.

This property becomes available when the CalculationType property is set to Accumulator. AVEVA™ Production Management uses it to filter out minor fluctuations in accumulated values.

Any number

HistorialFieldExpression

Specifies the value or source of value to be stored.

Click Browse (...) to open the Expression Editor. Use the Expression Editor to build an historical expression that defines the raw field value.

Any valid expression