5 Replies Latest reply on Oct 24, 2018 10:11 PM by jjohl

    Pi Notifications for Pressure change

    pbrett

      I want to send a PI notification if the pressure increases by a certain amount (8mbar).

       

      I have a PI Tags - Chamber Pressure & Cycle Status.

       

      Essential I want to send a notification when the Cycle status is active and the change in pressure of this time is greater than 8mbar.

       

      Is it possible to do this with these two tags?

        • Re: Pi Notifications for Pressure change
          Lal_Babu_Shaik

          Hi Patrick

           

          I would suggest to create event frame with

           

          start trigger  : status=active and pressure>8

          end trigger: status <> active or pressure<8

           

          Create notification rule using event frame template and add notification format or use default.

           

          Additional reference:

          PI Server

           

          Thanks

          Lal

          1 of 1 people found this helpful
            • Re: Pi Notifications for Pressure change
              pbrett

              Hi Lal

               

              Thank you for your suggestion however I don't think this will work. I don't think my original post was clear.

               

              The trigger that you have above will happen when the status is active and when the actual pressure is greater than 8. What I need is a notification when - the pressure differential, while status is active, is greater than 8 - not the actual pressure itself.

               

              Not sure how I can do this?

               

              Thanks again for your help.

               

              Patrick

                • Re: Pi Notifications for Pressure change
                  KarlRickards

                  Patrick have you tried creating the dP tag as an AF attribute?  You can then in Analyses make an IF THEN ELSE expression to trigger true once these two conditions are met.

                   

                  if 'Attribute1'="ACTIVE' and 'attribute2'>=8 then true else false

                  • Re: Pi Notifications for Pressure change
                    jjohl

                    For a differential, you can use the Rate expression in Asset Analytics e.g. Rate('pressure'). This calculates:

                    (current value – previously evaluated value) / (current timestamp – timestamp from previous evaluation)

                    Also as an aside, it can be hard to do an differential over a small time period if your data comes in with high frequency and a lot of noise, so I would experiment using the Rate expression with periodic scheduling to find what you're looking for if Event Scheduling doesn't get what you are looking for.

                • Re: Pi Notifications for Pressure change
                  KarlRickards

                  Hi Partick,

                   

                  Providing you are using AF 2016R2 or later and have migrated to that version of Notifications then Lal's suggestion will be perfect.  Alternatively if you are still running Notifications 2012 this can be built in the Notifications plugin without Event Frames providing you have added the relevant process variables as attributes in your AF Element Hierarchy.