Understanding Historical

Information that is required for report and accounting purposes is saved to the Historical database. Data from the RealTime database (RTDB) is stored along with information about the connections between remotes and the AVEVA Enterprise SCADA system.

A full implementation of computers running Microsoft SQL Server is used to effectively manage Historical data and administer related Historical services.

Historical is composed of databases that are designed to receive data from the RTDB. The following diagram provides an overview of how the Historical database relates to the RTDB, the easy eXtended Operator Station (ezXOS), and other offline media.

The following are transferred from the RTDB to the Historical database:

• Selected data from analog, remote, status, and accumulator-type rate points

• Events raised for configuration changes to RealTime points and changes to user editable data

• Alarm Messages (telemetry, application related, Controller commands and acknowledgements)

• Communication statistics

• An audit trail of all modification events

Data obtained from analog and rate points can be summarized to provide hourly, daily, monthly, and yearly summaries. These data can be manually edited, plotted, and then archived to offline storage.