Tags are obsoleted from a DataSet at the data collector level or in the historian, depending on the collector being used. If using the Logger Admin or OPC Collector, tags can be removed from the logging session which will then create a new file in the historian when these changes are applied and logging resumes. If using any other source of data collection, follow these steps:

1. Remove the tag from the logging source. Tags being actively logged cannot be obsoleted from the DataSet.
2. Open the Canary Admin application, navigate to the Historian tile, select the appropriate DataSet, and navigate to the most recent HDB file.
3. From within the HDB file, filter the tag list for the tags you wish to obsolete and download the list as a CSV file by selecting the downward arrow icon right of the filter box  
4. Uncheck the 'Include parent path' feature 
5. Save the file locally
6. Within the Historian tile, navigate back to the view of all DataSets
7. Highlight the DataSet you wish to obsolete tags from and select the down arrow icon from the 'DATASET' window, then choose 'OBSOLETE TAGS'
8. Upload the CSV file with the list of tags you wish to obsolete and click 'ok'

Remember, tags cannot be obsoleted if they are still being actively logged. You must stop logging on all tags you wish to obsolete prior to trying to remove them.

If the process is not successful, a .txt file will be generated with the reason the tags were not obsoleted.  That file will be created in the same folder as the CSV file you uploaded.  

The obsoleted tag(s) will still appear in the active HDB file, however they will be immediately removed from any client browsing.  Upon the start of a new HDB file, the tag(s) will no longer be listed.  You may manually force the rollover of the current HDB file if you wish to verify.