Tag database status

To provide the status of the tag database for the Logix processor cached in the ABCIP Communication Driver, this version of the Communication Driver will implement a predefined, read-only system variable, $Sys$TagDBStatus, of type VT_I2.

This system variable takes on any of the following values:

• 0 – No tag database

• 1 – Uploading tag database

• 2 – tag database uploaded

• 3 – tag database upload failed

The value of $Sys$TagDBStatus can only be changed by poking to the system variable $Sys$UpdateTagInfo. Poking a TRUE to $Sys$UpdateTagInfo while $Sys$TagDBStatus is 1 will not cause consecutive tag database uploads to the ABCIP Communication Driver.

Note: $Sys$UpdateTagInfo and $Sys$TagDBStatus are only available as item names associated with the Logix processor.

Regardless of the status of the tag database upload, the ABCIP Communication Driver periodically syncs the tag database from the controller. The Logix5000 controller has a journaling capability that keeps track of the changes in its tag database. Whenever the tag database in the Logix5000 controller is changed, a new journal and version are generated within the controller.