Rate Row Edit: Rate Averages and Integration tab

Rate EGU Units

Enter the text string label representing the engineering units (EGUs) for the rate (for example, barrels/hr or kWh).

This string appears in easy eXtended Operator Station (ezXOS) displays and is used for display purposes only; it has no effect on system calculations.

For a rate value, the units entered here appear in the Source Unit field of the unitConv record associated with this rate record. For further information, refer to Unit Conversion.

Enable Averages

Select to calculate the averages of the rate for the hour, day, month and year.

Alternate Accum Units

For an accumulator value, enter the units that appear in the Destination Unit field of the unitConv record that you want to associate with this rate record.

For further information, refer to Unit Conversion.

Alternate Rate Units

For a rate value, enter the units that appear in the Destination Unit field of the unitConv record that you want to associate with this rate record.

For further information, refer to Unit Conversion.

Enable Integrations

Select to have the system calculate the total quantity (for example, volume) over a given time period. These hourly accumulated values are stored in the accum database in Historical. Refer to the AVEVA Enterprise SCADA Historical Administrator documentation.

Note: Under certain conditions, the system only performs integrations on non-owning systems on a minutely basis, regardless of poll rate. This can result in small differences in integrated values between systems. Under the following conditions, the system integrates the rate value on the non-owning system:

• The Input Type field on the Main tab is set to Analog Only.

• The Software Accumulator checkbox is clear.

• The current rate is not changing more than the Replication Deadband, which in turn does not force replication and recalculation on the non-owning system at poll time

  Tune the Replication Deadband for the rate point accordingly.

  Important: For statistics to be calculated minutely on non-owning systems, you must configure the "Enable Statistics" Distributed Systems (DistribuSys) privilege.

Integration Scale Factor

The Integration Scale Factor is only used for rate points whose Source of Data as configured on the Main tab is Analog input. If the analog input was previously scaled by the Scale Factor, only set the Integration Scale Factor to 1.

• Integrated Hour Total = Previous Integrated Hour Total + Scaled Delta Accumulator * Scale Factor

• Integrated Shift Total = Previous Integrated Shift Total + Scaled Delta Accumulator * Scale Factor

• Integrated Day Total = Previous Integrated Day Total + Scaled Delta Accumulator * Scale Factor

• Integrated Month Total = Previous Integrated Month Total + Scaled Delta Accumulator * Scale Factor

  Rate points whose Source of Data as configured on the Main tab as either Pulse input or Pulse & Analog do not have the Integration Scale Factor applied when integrating.

• Integrated Hour Total = Previous Integrated Hour Total + Scaled Delta Accumulator

• Integrated Shift Total = Previous Integrated Shift Total + Scaled Delta Accumulator

• Integrated Day Total = Previous Integrated Day Total + Scaled Delta Accumulator

• Integrated Month Total = Previous Integrated Month Total + Scaled Delta Accumulator

Integration EGU Units

Enter the text string label representing the EGUs for the rate integrated over a time period (for example. quantity units such as barrels or kW).

This string appears in easy eXtended Operator Station (ezXOS) displays and is used for display purposes only; it has no effect on system calculations.

For an accumulator value, the units entered here appear in the Source Unit field of the unitConv record associated with this rate record. For further information, refer to Unit Conversion.

Apply Linear Filter

Select to apply a filter to the telemetry/calculated values that smooths out brief fluctuations. The equation used to calculate this is:

V filter = (V current * K) + [V previous * (1-K)]

where:

• V filter is the filtered value.

• V current is the current unfiltered value.

• V previous is the filtered value from the previous Omnicomm scan.

Filter Constant

Enter a filter constant value.

This must be greater than 0 and less than or equal to 1. The smaller the value, the greater the smoothing (for example, when the Filter Constant is 1.0, no filtration is performed).

Number of Averaged Samples

Enter the number of readings the application should use in calculating the arithmetic mean.

For further information, refer to Jitter Smoothing.

Enable Software Accumulator

Select to enable the software accumulator. When a remote is powered on, the Power On bit is set in the Remote Status Word (RSW), and all the remote’s accumulators are usually reset to 0. If Enable Software Accumulator is selected, an internal accumulator value is maintained so it can compensate if a power failure at the remote resets the value to 0.

To indicate power failure for this option, the remote protocol must be able to set the remote’s RSW that is stored in the RSW field specifier. The system reads the RSW and if it detects that power has failed at the remote, it compensates for the remote’s accumulator.

For example, if the current accumulator value is 123456 and the remote suffers a power failure, the remote will return an accumulator rate value of zero and an RSW when the power is restored. On the next poll, if the remote returns an accumulator rate value of 10, the system updates its internal software accumulator to 123466 (123456 plus 10).

Scale Factor

The scale factor can affect the rate output in various ways depending on the input type of the point.

For reference, note the following:

• The rate table's acccur field is the current accumulator value.

• The rate table's currate field is the current rate value.

• ScaledDeltaAccum is an internal variable used as the input to the integration calculation.

• DeltaTime is either the time between the current and previous poll or a manual update to the rate point value. If the point is in a manual state, the TelemeteredTableMonitor process updates the poll time during minutely integrations for Analog Input points.

Pulse Input

The scale factor scales the CurrentRate, the ScaledDeltaAccum, and the CurrentAccum.

Software Accumulator Off:

Software Accumulator On:

Pulse & Analog Input

The scale factor scales the ScaledDeltaAccum and the CurrentAccum.

Software Accumulator Off:

Software Accumulator On:

Analog Input

The scale factor scales the CurrentAccum (when the software accumulator is enabled) and the ScaledDeltaAccum.

Software Accumulator On: