Understand the accumulator volume and mass reset functionality

It is possible to reset the accumulated volume and mass fields of an accumulator to sync up the values with those reported by the underlying rate point. This functionality can be useful when the accumulator volume unintentionally deviates from the rate reading.

Volume and mass reset procedure

Set the ResetGSV RealTime field to yes using one of the following methods:

1. iSQL: UPDATE accumulator SET resetGSV = ‘yes’ WHERE name like ‘accumulatorname’;

2. dbput: dbput accumulator.accumulatorname.resetGSV yes.

In the processing cycle immediately after setting the ResetGSV field to yes, the following volume values are reset to the current accumulated rate reading (rate.acccur):

• TrackingAccumulatedVolume

• MonotonicAccumulatedVolume

• MonotonicAccumulatedGSV

• MonotonicAccumulatedGV

• TrackingAccumulatedGSV

• TrackingAccumulatedGV

• IV (IndicatedVolume)

• GV (GrossVolume)

• GSV (GrossStandardVolume)

The following mass fields are recalculated based on the accumulated rate reading and the density reading:

• Mass

• TrackingAccumulatedMass

• MonotonicAccumulatedMass

The ResetGSV flag will automatically be set back to no at the end of the processing cycle.

Important: No volume corrections are applied when the fields are initially reset. The GSV will be updated with the corrected volume in the next cycle.

Generally, when a reset is applied, mass is calculated by multiplying the accumulated rate volume by the corrected density. However, if the accumulator is configured to use API 11.3.2.1 (Ethylene), the procedure described in section Process Ethylene with a linear meter will be applied after the reset.

If the parent Virtual Flow Computer (VFC) is used as an input into other applications (like Countdown), resetting accumulator volume and mass fields might have unintended consequences.