8 Replies Latest reply on Jul 19, 2018 2:31 PM by aecaruso

    Pi Vision Refresh Rate

    aecaruso

      Hi,

       

      I am fairly new to the PI system and this is probably a really basic question, however, I have not easily found the answer. I am displaying some values on a Pi Vision dashboard with a desired refresh rate of 1 minute, however, it is refreshing every 2 minutes. The data itself is updated every 30 seconds (I am creating Pi Points using a linked table from a SQL database). How do I go about setting a refresh rate in Pi Vision?

       

      Thanks!

        • Re: Pi Vision Refresh Rate
          rschmitz

          Hi Anna,

           

          All non-PI Point Data References are coded to update once every 2 minutes because of the way the AF SDK does caching when retrieving values for non-PI Point references, Vision will pull from the most recent cache value to update for these points until the cache expires and the AF SDK on the Vision machine queries for the updated value of that non-PIPoint attribute. That being said, all PI point attributes update once every 5 seconds in PI Vision if there are any updates.

           

          So this raises the questions for me, what exactly are you trying to pull in? Is it a PI point? Is it an AF attribute mapped to a PI point? Is it an Analysis data reference that is using a PI point as it's input without any manipulation? etc.

           

          Cheers,

          Rob

          1 of 1 people found this helpful
            • Re: Pi Vision Refresh Rate
              aecaruso

              Hi Rob,

               

              This might explain it. What I am actually showing is (I believe) an attribute mapped from a Pi Point. To explain a bit more, I am dealing with data from a SQL database (nothing in the pi system) and am calculating the total product made throughout the day. I have done this by first creating a pi point that shows how much product was made in the last 30 seconds, I then find the total of all pi tags in the point. This value is what is shown in Pi Vision. Does this make sense? Does it then make sense that it is only updating every 2 minutes? Is there any way around this?

               

              Thanks so much!

               

               

              Anna

                • Re: Pi Vision Refresh Rate
                  VasanthakumarR

                  Hi Anna,

                   

                  Can you provide the following details to us to understand this issue in a better way,

                  - Are you using Table Lookup in AF to connect to the SQL database and get the data?

                  - Are you using RDBMS interface to get the data from the relational database and store the data in PI (PI Points)

                  - Where are you calculating the Total, in SQL side or in PI side? If it is in PI side, is it an Analyses calculation (PI Point or AF Attribute)?

                   

                  For your information, Vision web server handles analysis data references and does the calculations. The default update rate is 2 minutes. So if you can provide the above details, it is easy for us to find the solution.

                   

                  Regards,

                  Vasanth.

                    • Re: Pi Vision Refresh Rate
                      aecaruso

                      Hi Vasanth,

                       

                      I am using a linked table and table lookup. The values from the table lookup are being stored as pi tags every 30 seconds. I am creating an attribute within pi that is calculating the total (Tagmean() * EventCount()). This is the value being displayed on vision.

                       

                      Best,

                      Anna

                        • Re: Pi Vision Refresh Rate
                          VasanthakumarR

                          Hi Anna,

                           

                          Thanks for the details provided.

                           

                          As you mentioned that you are using Table Lookup to get the data from SQL database, it should be stored as PI AF attribute, not as a PI Point and also you have mentioned that you have created the calculation and stored it as PI AF attribute, so all non-PI Point Data References are coded to update once every 2 minutes, if you want to update as per the source system in PI Vision, store the calculation result in PI Point and map it to the PI Vision display.

                           

                          Regards,

                          Vasanth

                    • Re: Pi Vision Refresh Rate
                      aecaruso

                      Is it at all possible for me to change the update rate of any non-PI Point Data References from 2 minutes, or is this completely on OSI's side of the equation?

                      I have a limited number of PI Points available to me, so anything that I can create as an attribute would be helpful!

                       

                      Best,

                      Anna