Configure the Calculation Type property for fields

None

If the field does not perform a calculation, set the CalculationType property to None.

Accumulator

An Accumulator Field keeps a tally of the accumulated total, but it does not supply a value to the reporting point until the reporting point triggers. An example of an accumulator field is one having a tag that counts the number of items that the plant produces. AVEVA™ Production Management does not capture the actual value of the tag; it captures the difference between the current value of the tag and the value of the tag when the last record was captured.

Integral

Calculates and stores the area that is represented if the sample stream is plotted on a 2-dimensional Cartesian coordinate graph.

Average

Calculates and stores the average sample value for a given sample stream period.

Time Weighted Average

Time weighted average is a mode of interpolation. Unlike a normal average that provides a flatline average between two known points, the data is time-weighted to provide a gradual ascending line.

Minimum

Calculates and stores the minimum sample value for a given sample stream period.

Maximum

Calculates and stores the maximum sample value for a given sample stream period.

Inventory

This is an advanced setting. Add the capture value to the inventory value to keep a running total of inventory value. The last inventory value is the inventory value at the last sample time. To modify the last inventory value, select Browse next to the LastInventoryValue property. The Edit Inventory Value dialog box appears where you can modify the last inventory value.

AccumulatorResetPoint

The calculation behavior after a negative transition, 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

This property becomes available when the AccumulatorResetPoint is set to DefinedResetValue. The property specifies the value at which the accumulator resets.

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

AccumulatorThreshold

A fluctuation threshold for difference in values. 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. 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.

Any number