Reference, Installation, and Operations Manual

Section 6: Meter operation

3-9000-743 Rev S

June 2013

 

 

 

6.1.3Batch cycle processing

Batch update period

Calculation updates performed by the meter, for deriving volume and velocity, are based on batches of data samples collected from sequences of transducer firings. The batch update period is dependent upon the user specified batch update period (SpecBatchUpdtPeriod) and the stack size (StackSize) as shown in Table 6-1. The Standard batch update period is the default.

Table 6-1 Actual meter update period

 

 

StackSize

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 (None)

2

 

4

8

16

 

 

 

 

 

 

 

 

SpecBatchUpdtPeriod

Rapid

0.25 sec

N/A

N/A

N/A

 

N/A

(250 ms)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Standard

1 sec

1 sec

1.5 sec

3 sec

 

5 sec

 

(1000 ms)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The actual batch update period is readable via the BatchUpdatePeriod data point.

Emission rates

The emission rate is the period between firing two different transducers. The stacked emission rate is the period between consecutive firings of a single transducer when stacking is used (i.e., the stack size is not set to ‘None’).

The actual emission rates used (readable via the EmRateActual and StackEmRateActual data points) are functions of the desired emission rates, meter type, firing sequence, stack size, and filter status.

The user specifies the desired emission rates via the EmRateDesired and StackEmRateDesired data points. If a desired emission rate is set to zero, the meter uses the fastest possible emission rate (which can be as short as 4 milliseconds). Otherwise, the meter uses the fastest possible emission rate that is not less than the desired value.

When using the Daniel MeterLink Update Time Wizard to configure the meter (as discussed in Section 5.7.1), EmRateDesired and StackEmRateDesired are set to zero to achieve the most transducer firings per batch update.

Batch cycle processing

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