About system driver and system tags

The system driver is an internal process that monitors key variables within an operating AVEVA Historian and outputs the values by means of a set of system tags. The system driver runs as a Windows service and starts automatically when the Historian is started.

The system tags are automatically created when you install the Historian. Also, additional system tags are created for each IDAS and replication server you configure.

The current value for an analog system tag is sent to the Storage subsystem according to a specified rate, in milliseconds. All date/time tags report the local time for the Historian.

Legacy tags from upgraded systems may be retained.