5 Replies Latest reply on Jan 14, 2014 3:49 AM by ainwood

    Tag Attributes for a Manual Tag

    ainwood

      We have a PI tag that we use for setting targets.  Eg. if we want to flow to a certain number, we write the new target to this tag, then trend progress against it. This works fine, except we then aggregate several targets together in a sum.  The problem we have is that if one of the targets isn't changed, then we get "timeout" or "shutdown" and the aggregated total fails.

       

      Note that the data load is not high.  We have 4 of these tags, and generally we write 1 - 2 values per day, so I don't see any performance problems in turning off compression etc.  The problems we get are caused because we don't change the tags often enough!

       

      As I see it, if I change the "Shutdown" attribute of the tag to 0, then it should not ever write a Shutdown event - in which case, does it still retain the previous value all the time? 

       

      On the assumption that the above is correct, I think that in addition to this, I also need to change the Compression and Exception reporting settings.  Can someone give me advice as to which ones to change?  I assume I want to turn-off Exception reporting (ExcMax=0 and ExcMin=0).  Do I need to change compression settings as well?

       

      Thanks,

       

       

       

       

       

      Andrew

        • Re: Tag Attributes for a Manual Tag
          Lonnie Bowling

          Hi Andrew,

           

          What are you using for a point source for the tags? I think you should be using "L" for lab tags unless your data is coming from some other system that requires an interface. This should prevent the errors you are seeing. If you are using an interface, it would be helpful to know that.

           

          Lonnie

            • Re: Tag Attributes for a Manual Tag

              Agree with Lonnie. If it is an interface then yes you could switch exception off and compression off (although you may only want to compress consecutive duplicate values instead).

               

              Shutdown is usually written when you restart the PI Server if you are running the Shutdown subsystem, I disable that bad boy as a standard - you should evaluate your own needs, I'm not saying everyone should disable it.

               

              The timeout (I/O Timeout??) state suggests an interface is being used, so you would want to look at the interface configuration to suppress I/O Timeout states from being written, which you can do in interfaces such as the PI Interface for OPC DA.

              • Re: Tag Attributes for a Manual Tag
                ainwood

                Thanks.  The point source is "L".  I may have got the error message wrong - trying to trend the tag, I only see a "Shutdown" message.  I'll turn-off Shutdown.  

                 

                Re an Interface - not sure (I'm not the administrator, just a user trying to fix a problem using the Excel SMT add-in).  

                  • Re: Tag Attributes for a Manual Tag

                    Hello Andrew,

                     

                    Please accept my apology since I am not exactly sure what the problem is. "Shutdown" is a status that is written e.g. by PI Shutdown subsystem in case the PI Server becomes shut down and a tags shutdown attribute is set to 1. If your concern is the "Shutdown" status event, setting the tags shutdown attribute to 0 to avoid "Shutdown" becomes written by PI Shutdown subsystem is the first action. The "Shutdown" event will sit in the tags snapshot (most recent event) until it's either pushed out by a more recent event or deleted. This said, you can either update the tags snapshot with a new event or delete the "Shutdown" event. Both can be done e.g. by using the Archive Editor add-in of PI System Management Tools (PI SMT).

                     

                    Because you state, that you are not the administrator of this PI System, I understand you are not asking for your vCampus development PI System but for a production PI System. You may want to work with the PI Systems administrator. Alternatively we can offer you to work with an OSIsoft Technical Support Engineer (TSE) in a remote session. Please let us know if you would like to receive a call from a TSE.