3 Replies Latest reply on Jun 29, 2012 12:21 PM by RJKSolutions

    AF, substitution parameters question

    aubinf

      Hi All,

       

       

       

      Our situation:

       

      We have multiple sites and each site runs their own AF Server.

       

       

       

      Problem:

       

      When I connect to a remote site using PI-System Explorer from my PC and look for any attributes, the “PI Point” resolution did not make it right.

       

      The “%Server%” (part of the PI Point) seems to be resolved from my PC and not from the site AF Server.

       

       

       

      I have looked into the AF documentation and found this:

      %Server%

      Name of the default PI Server of the PI AF database in which the attribute resides.

       

       

      Am I using the wrong parameter ?

       

       

       

      Any help?

       

       

       

      TIA

       

       

       

      François

       

       

        • Re: AF, substitution parameters question
          Ahmad Fattahi

          It appears that when you reference a PI AF attribute value in data reference attribute, PI AF uses the value of the attribute at the time you created or updated the data reference. PI AF does not evaluate that attribute value again, unless you update the data reference.

           

          Can this be explaining the behavior you are observing?

            • Re: AF, substitution parameters question
              mhalhead

              Hi François,

               

              The data references in AF run on the client. Therefore, when you do a reset or create a new element the %Server% resolves to the clients default server. This can be more than a little painful when you deal with multiple servers and have multiple individuals working on AF.

               

              As a work around I created an AF table that maps the PI servers to their AF servers. I then created an element which does a lookup using the %System% to determine its partner PI Server. I use this element attribute in the point configuration string of the templates. I've stuck a screenshot in below which shows the setup, I did blank out the server names (call me paranoid).

               

              This actually works surprisingly well.

               

              2678.PIServerLookup.png