By default, Configuration Change CRC values are not exposed via the ViewX or WebX client interfaces, or recalculated automatically following each user-instigated configuration change. If you want to use the CRC values to determine whether configuration changes have occurred in your database since taking a 'snapshot' of that database, you have to enable this functionality. Once enabled, users with the relevant permissions will be able to view the Configuration Change CRC values via the ViewX and WebXinterfaces. Additionally, you will be able to use the Configuration Change CRC values programmatically to determine whether configuration changes have occurred since the CRC values were recalculated.
To make the Configuration Change CRC and Configuration Change Group CRC values available in ViewX and WebX:
- Display the Server Configuration Tool and log on if required (see Accessing the ClearSCADA Server Configuration Tool in the ClearSCADA Guide to Server Administration).
- Expand the Global Parameters branch of the tree-structure.
- Expand the Advanced branch.
The Advanced settings are displayed. - In the Configuration Change CRC section, select the Calculate for Database Objects check box.
- Apply the changes to the server.
- Restart the server for the changes to take effect and for ClearSCADA to calculate each database item's Configuration Change CRC value (and each Group, Group Instance, and Group Template's Configuration Change Group CRC value).
- On a multi-server system, repeat the procedure on the other servers on your system.
(To disable the functionality, follow the above procedure, but clear the Calculate for Database Objects check box. ClearSCADA will still calculate other CRC values internally, but will no longer monitor or recalculate the Configuration Change CRC or Configuration Change Group CRC values that can be exposed via the ViewX and WebX interfaces.)
Further Information