Renaming Digital States

If digital states are renamed in the PI Collector, the corresponding enumerated sets in Historian are not automatically renamed without a restart of the PI collector. Unused enumerated sets cannot be automatically deleted, because the PI Server does not notify the PI collector about rename activity.

When a digital state is renamed, a new enumerated set is created. There will therefore be two enumerated sets for the same digital set, one of which has the old name and one of which has the new name. The old enumerated set is redundant as it will not get any data if no tag is assigned to it. The tag association is also lost.

To address this:
  • Manually assign the new enumerated set to the applicable tag in Historian. It will then be synchronized to represent the data for the renamed digital state.
  • Go to the Historian VB admin and delete the unused enumerated set at the Historian side.
For example, consider the following situation, where PHsite1.PumpStatus in Historian is assigned to Tag1:
PI ServerHistorian
ON= 0OFF= 0
OFF= 1ON= 1

If the digital state Site1.PumpStatus is renamed to SiteLodha.PumpStatus, a new enumerated set PHSiteLodha.PumpStatus is created at the Historian side.

The old enumerated set on the Historian side PHSite1.PumpStatus will not show any data, but it will exist redundantly inside Historian.

To address this:

  • Manually assign Tag1 (applicable tag in Historian) to PHSiteLodha.PumpStatus.
  • Go to the Historian VB admin and manually delete the old enumerated PHSite1.Pump Status.