Late data check

The check defined as the Late Data Check ensures that measurement data is entering the measurement system on schedule.

The Late Data Check is scheduled to run periodically against all meter and gas quality (GQ) points that have this check enabled. The number of periods is specified in the LateDataDesc (LateDataDesc) table in SQL, a task performed by your Administrator. By default, the check is performed every 30 seconds. You can view the frequency at which the check is being performed in the Task List. It is called missingLateData. The check frequency is displayed in the Interval column.

If the data does not arrive in the system after the defined time period, it is considered late. If no estimation method is specified, a NULL Historical record is created for the missing row and a problematic context record is raised. Otherwise, the data is estimated using one of the techniques.

The following algorithm is used to detect late data entries. The algorithm displays a calculation performed at an hourly meter frequency.

Where:

• Host = Clock time on the server at Greenwich Mean Time (GMT) (seconds).

• Offset = Difference between GMT and the field equipment’s time zone (seconds).

• Last = Last reading at chosen granularity. This information comes from the information collected from the Historical Timestamp Override. So for example, if you were looking for information at an hourly granularity, it would come from the Last Hourly Read row in the Historical Timestamp Override window.

• Tol = Limit tolerance. The Limit Tolerance, or granularity at which the meter data has been received, is defined in the Meter frequency row of the MTR Late Data Check section in the Properties for Meter window.

The processing will continue if the outcome is true or false. If the data fails the check, the system will:

• Generate a problematic context record.

• Estimate the data.