Remove A Tag

About this task

When you remove a tag, it is removed from the tag database, but all data for that tag is retained in the archive and the tag name cannot be reused. Since the tag data is still available from the archive, you can still reference that tag from within a calculation formula, for example, or by using the Excel Add-In.

If, however, you want to remove the tag data as well from the archive, you can delete it permanently.

Whenever you delete/remove tags, the following collectors reload only the modified tag(s) without restarting the collectors.
  • OPC Collector
  • iFIX Collector
  • Calculation Collector
  • Simulation Collector
  • Server to Server Collector
  • PI Collector
  • PI Distributor

By default, the On-line Tag Configuration Changes option is enabled, which allows a tag to stop and restart data collection without restarting the collector. If you disable the On-line Tag Configuration Changes option, any changes you make to the tags do not affect collection until you restart the collector. To enable or disable the On-line Tag Configuration Changes option, access Historian Administrator, and then select Collectors > Advanced.

Restarting the collector stops and restarts the tag(s) collection and may record bad data samples to the collection. All the collector configuration changes done within a 30-second time frame are batched up together. To collect the modified data faster, update/modify a small set of tags at a time. If the modified tags get zero bad markers and available runtime values at the same time, then precedence is given to available runtime values instead of zero bad markers.

Tip:
  • To collect the modified data faster, update/modify a small set of tags at a time.
  • When updating large sets of tags at the same time, the best practice is to disable the On-line Tag Configuration Changes option and restart the collector after modification.

Procedure

  1. Access Historian Administrator.
  2. Select Tags.
  3. Select the tag that you want to remove.
  4. Select Delete.
    The Delete Tags window appears.
  5. Select Remove Tag from System, and then select OK.
    A message box appears, asking you to confirm that you want to remove the tag.
  6. Select Yes.
    The tag is removed.