Each workstation includes a Continuous Historian subsystem that detects and stores historical data and an Alarms and Events subsystem that detects and stores system events and alarms. The Continuous Historian subsystem monitors modules for history collection on an area basis and the Alarms and Events subsystem monitors for events and alarms on an area basis. If you move a module from one area to another, history collection moves with the module. For example, if a Continuous Historian subsystem is collecting historical data from a module in AREA1, and you move another module to AREA1, all the history collection for that module is automatically added to the AREA1 Continuous Historian subsystem.
You can establish duplicate data acquisition and storage by assigning an area to two or more Continuous Historian subsystems.
You must assign the areas from which you want to collect history to the subsystems, enable history collection on the workstation, and download the workstation through DeltaV Explorer to activate the subsystems and view the data. You can set up history collection for modules using either DeltaV Explorer or Control Studio.
In the following procedures we will assign area TANK-101 to the Continuous Historian and Alarms and Events subsystems, enable history and events collection on the workstation, download the workstation, and view the data with the Process History View application.