About histories

Histories are ordered collections of time-stamped records. A single history record (or history) is a collection of specific data values from a component within any station—local or remote. For example, a data log is a history.

History services

Each station’s History space supports three history services. These services appear by default under the Config > Services node in the Nav tree.

The HistoryService manages the History space, collecting and storing all histories in the station database. This service is required to provide database support for histories in each station.
The AuditHistoryService monitors station configuration. A change made by a user to any component property creates a standard audit event record, and a change to a security-related property creates an additional security audit event record in the History space. Authentication events (log in and log out) create security event records in the History space.
The LogHistoryService collects some of the messages available in a station’s standard output for troubleshooting purposes.

History space

The History space provides ways to view and working with histories in the history database. The History node in the Nav tree visually represents the History space.

Once you have a history service running, you can access histories in the database using the history ORD scheme. The unique history scheme name “history” and each unique history ID provide identification for the individual histories. This unique ID identifies all history collections. To access a history in the History space, expand the Nav tree or click the file open icon and click Ord. This opens the ORD window.

History views present history information in various formats for both analysis and editing. Views on the History space include the following: Chart, History Chart Builder, Database Maintenance, and Nav Container View.

History records

Histories are organized by their source station (device).

Figure 1. History records in a Supervisor station

The screen capture shows the history records that appear, by default, under the History > local (station name) node in the Nav tree.

History configuration

Using histories involves a process of collecting, storing and archiving data. You can configure the history collection process to collect the data that you need and store the history records where you want them - locally or remotely.

History configuration includes working with properties such as ID, History Source, Timezone, Record Type, and more.

The History Grouping component uses history properties to customize the organization and display of History space contents.

History Nav shortcuts provide convenient navigation links to histories.

History data editing

You can edit and filter the history data in Workbench using the History Editor view.

History archives

Creating history import and export descriptors is how you save (archive) histories to a different location (station) from where they originated.

For example, an originating history in a remote controller station may collect only the last 500 records. If imported to a Supervisor station, you can configure the history (using its history import descriptor) with unlimited record capacity.