This topic applies to points that support the Override feature.
The Override feature enables a point's value to be overridden temporarily, using the Override pick action. While the point's value is overridden, the 'live' point data is 'put aside' in favor of the locally overridden value. The point's Status display includes attributes that indicate whether an override is in force, and if so, provides information about both the current (overridden) value and the Put Aside data.
With points that support the Override feature, you can specify whether ClearSCADA is to store the 'put aside' data historically. You might find such data storage useful, for example, if you want to verify the data stream that ClearSCADA has retrieved from an instrument, before removing the override in force on the database point that represents that instrument.
To store Put Aside data historically:
- Display the Point Form for the point that you want to configure (see Display a Form in the ClearSCADA Guide to Core Configuration).
- Select the Historic tab.
The Historic tab is only included on the relevant configuration Forms when the Historic Data feature is enabled on the server. The feature enables ClearSCADA to store data historically (see Historic Data Storage Settings).
- Ensure that Historic is enabled (see Enable or Disable Historic Data Storage).
ATTENTION: With points on some drivers, ‘Historic Data Filter’ properties are used to define the type of reported point data that ClearSCADA is to store historically for those points. With such points, reported point values are only stored historically if historic is enabled on the point’s Historic tab, and at least one option other than ‘None’ is selected within the Historic Data Filter section of the Point Form. The driver-specific guides provide details about any points that have Historic Data Filter properties.
- Select the Put Aside check box.
When Put Aside data is stored historically for a point, you can view the stored data on Trends. To do this, the trace for the point has to represent Raw Historic data, and be configured to display Put Aside data (see Configure a Trace in the ClearSCADA Guide to Trends).
ATTENTION: Enabling the historic storage of Put Aside data might result in a large number of historic records being stored online while an Override is in force. (For example, if the sensor with which a database point is associated malfunctions in such a way as to result in frequent value changes being reported to ClearSCADA while the point is overridden.)
By default, ClearSCADA does not store Put Aside data historically; this is indicated by the Put Aside check box being clear. When ClearSCADA does not store Put Aside data historically, only the most recent Put Aside value is available during an Override from the point property PutAsideValueFormatted.
- Save the configuration.
Put Aside data is marked as 'Put Aside' when stored. As such:
- To query historically stored Put Aside data, you need to query the CDBHistoricAll table
- Historically stored Put Aside data is excluded from export to other historian interfaces, such as Wonderware Historian, and eDNA
- Historically stored Put Aside data does not affect Historic Aggregates or Historic Calculations.
Further Information
Override and Put Aside status attributes: see Override in the ClearSCADAGuide to Drivers
Receive notification that the Historic Data granule is nearing its size limit: see Define the Acceptable Limits for Historic Data Files in the ClearSCADA Guide to Core Configuration.