Historic data and events are usually deleted from the system after a defined period of time (typically, they are archived before they are deleted). When the historic data and event messages are deleted, they are no longer available online (users will need to mount an archive to access the historic / event data).
The Historic Regions feature, allows you to retain historic data and events that are logged within a specific time period (called the Historic Region). ClearSCADA does not delete historic or event data that is logged within the time span of a defined Historic Region. This data can be viewed on Historic Trends, Historic Lists and the Events List without having to mount an archive volume.
The Historic Regions feature also provides a navigational aid when using Groups and Lists—you can quickly access values that were logged in a named period of time (the Historic Region).
For more information, see the topics that are listed in the gray footer section at the bottom of this topic. Select the relevant entry to display the topic that you require.
You need to enable Historic Data to make use of Historic Regions (see Enable or Disable Historic Data Storage).
Further Information