4 Replies Latest reply on Apr 5, 2012 5:54 PM by DevBiker

    Efficiency of payloads

      Do you have any idea of the efficiency trade off of using PIEventBasic over PIEvent?


      Typically PIEventBasic is fine for a lot of needs, but right now I am quite interested in the questionable bit that comes with the PIEvent payload.  So, if I am running say 1,000 PI Points through an input adapter using PIEventBasic, will it be "slower" if I switched the payload to PIEvent?  (Is it additional calls under the hood to get the additional information, like the annotation?)  


      I should get some time to test it out this week but if you already know the answer, it would be most helpful.

        • Re: Efficiency of payloads

          Just to extend my question above slightly...if a value is marked as questionable after it has been processed by the Update Manager, I take it the adapters don't pick up that particular type of update?  So if I was totalising values within a window but wanted to exclude questionable data, any snapshot data that is manually marked as Questionable (for example, not by a PI OPC Interface) then I won't be able to alter the results on my standing query to reflect that?  

            • Re: Efficiency of payloads

              Hi Again


              I’m not really sure of the actual efficiency tradeoff between PIEventBasic and PIEvent.  I have used both, but I have not performed any scale testing.


              The slowdown should be associated with the bigger type and additional strings.  Status and digital strings are resolved during startup, so should not require additional calls to the PI System.  The annotation indication (i.e. does the event have an associated annotation) is associated with the event, so requires no additional call.  If the event does have an annotation (should be a rare occurrence), we need to make a call to retrieve the annotation.