Save historical data during run time

While an application is running, data is saved to the historian as follows:

• If no previous historical attribute value exists in the historian, the first value is always saved to the historian.

• Numerical attributes (double, float or integer): If the value for the attribute changes and that change is more than the value deadband, or the value's quality changes (for example, from Good to Bad), the data is saved to the historian.

• If the attribute type is qualitative (enumeration, string, or Boolean) and the attribute’s value or quality changes.

• If the current time exceeds the last Forced Store period occurred for the attribute by the time period that was set as the Force Storage Period. If no last Forced Store occurred since starting the object, a new store occurs immediately.

  Note: If enabled, the Value Deadband mechanism resets itself based on this new stored value.

• All new attributes value, timestamp, and quality are sent to the Historian for storage.

• The Historian stores the historical records to the database.