2 Replies Latest reply on Oct 13, 2015 1:54 PM by Lowreno

    How to build a rule (a PI-AF attribute / PI Notification ) when TAG value is not updated as the time expected ?

    Lowreno

      Hello guys!

       

            So, I have a tag called "point one" which a new value is expected around each five minutes.   If this role is broken, an attribute on PI-AF should be updated as "warning state".  When the tag "point one" back to the normal behavior (it means, that the value back to arrive around each 5 minutes on "point one"),  the attribute on PI-AF should back to "normal state".

       

           So, is it possible to do it on an attribute of template on PI AF?  Is it possible to use PI Notification to alarm this behavior ?

       

          Note: The values on "point one" can be updated between 4 and 6 minutes... the default is five minutes. When more than 10 minutes without any update, the alarm should be done.

       

          Thanks in advance,

       

      Lowreno.

        • Re: How to build a rule (a PI-AF attribute / PI Notification ) when TAG value is not updated as the time expected ?
          Marcos Vainer Loeff

          Hello Lowreno,

           

          I guess that there some options for you to solve this problem. I will give you one using PI Analysis Service and PI Notification.

           

          As you probably know, the PI Point sinusoid updates every 30 seconds. Let’s suppose I want to monitor an attribute that points to this tag and store the results on another attribute called “Sinusoid Status”.

           

          If the last sinusoid update was more than 10 seconds ago, the “Sinusoid Status” attribute should receive value 1. Otherwise, it should receive the value 0.

           

          Using PI Analysis Service through PI System Explorer, an analysis with the following expression is created:

           

          If Second('*') - Second(PrevEvent('Sinusoid','*'))>10 Then 1 Else 0

           

          It is important to choose the “Sinusoid Status” as the output attribute.

           

          Finally, select the periodic option for scheduling and 5 seconds for the periodic time between evaluations and click “OK”.

           

          The sinusoid status value will let you know if the status of the data flow of the sinusoid is valid or not according to what you have in mind. In our case, this tag will keep changing its value from 0 to 1 as sinusoid updates only every 30 seconds.

           

          With the attribute properly configured, you can create a notification to monitor this attribute and send a notification if he value changes from 0 to 1.

           

          You can apply this suggestion to your use case using templates as well!

           

          Hope it helps!