To enable logging, first configure logging options in the Project Library Properties dialog box then enable logging on the Logging page of the Shared Variable Properties dialog box when you create the shared variable.

After you enable logging, the Shared Variable Engine (SVE) acquires data from all shared variables for which you have enabled logging. The SVE then sends the data to the database, which logs the data.

To enable logging programmatically, use the Logging:Enabled, Logging:Log Alarms and Events, and Logging:Log Data SharedVariableIO properties.