11 Replies Latest reply on Jan 22, 2016 4:21 PM by pthivierge

    WebID for same tags in two different systems




      If I am developing a webapi app in my demo system using the Webid for the tags existing in my demo system, If I deploy the app to the production system, what is gonna happen with the WebID for the real tags? will they be the same?.


      Jaime Ramirez

        • Re: WebID for same tags in two different systems
          Rhys Kirk

          Web ID uses the GUID of the PI System, AF Element and AF Attribute. Those 3 GUIDs will differ between systems so your WebID will differ also.

          Same applies for a PI Point; the PI Data Archive Id and PI Point ID are both used and will likely differ between systems.

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            • Re: WebID for same tags in two different systems

              Hello Rhys and Jaime,


              WebID’s are coded based on an AF objects GUID and it’s path. GUID’s change when an object becomes deleted and re-created. When the GUID changes, the WebID changes too but PI Web API will still be able to find the object by its path. It tries to find the object by GUID first. If this fails, it tries to find the object by path. On a different PI System however, the path will be different too.


              With the above said, a PI Web API client should never persist or even hardcode WebID's because they may change. "Browsing" for assets could be one strategy but making use of the PI Index Search Crawler to find Elements, Attributes or PI Points is likely most efficient.

              3 of 3 people found this helpful