Duplicate tags or tag addresses

If the Tag Importer encounters a tag that already exists in the AVEVA Historian database, it can optionally add a string to the beginning or end of the tag name to make it unique within the Historian. During the import, you can select:

• Whether or not you want a string to be added.

• The string to add.

• The placement of the string, either at the beginning or the end of the tag name.

• Whether to add a string to all tag names from that node, regardless if they are duplicates or not, or to only add a string when a duplicate tag is detected.

If, by adding a string, you create a duplicate tag during the importing process, the Tag Importer does not import that tag. For example, you choose to prefix all tags from a particular node with the letter "B," and you are importing a tag named "TestTag." However, a tag named "BTestTag" already exists in the Historian. The Tag Importer does not import potential duplicate tags. To solve the problem of potential duplicate tags, change the names of these tags in InTouch HMI software to avoid the duplication and then try importing a second time.

If the Tag Importer encounters a duplicate address (consisting of the application, topic, and item) for one or more tags, the information is still imported. However, if you are using DDE and have duplicate addresses, only the first tag (per tagname order) actually receives data. This is a DDE limitation.