10 Replies Latest reply on Apr 8, 2018 10:52 AM by nkrstic

    Digital PI Point showing "Configure"

    nkrstic@kockw.com

      Hello all,

       

      We are having a strange situation, we are monitoring pumps which have a shutdown cause tag in a form of a number (413) vendors have provided a lookup information for the same where that number translates to a meaning example (413 = Manual Shutdown). We have several hundred of those as well as several vendors. Data is being received via OPC as advise tags, there is no compression or compression deviation, Interface is set to save good and questionable values.

      We created digital states for different vendors and digital tags that are mapped to corresponding states states. Location1=2, Location2=0, Location3=1, Location4=1, Location5=0.  For some of the tags we are getting the correct values but for some we are getting "Configure", knowing that this usually points to pi point/tag configuration we have crosschecked the instrumenttag. Using a OPC client we see the values in OPC but in PI we see either Configure or BAD. In the msg logs on the PI OPC Interface we see msgs. like .AddItem failed VT_I2....

       

      Any ideas?

      Nebojsa

        • Re: Digital PI Point showing "Configure"
          Steve Boyko

          It sure sounds like the instrumenttag doesn't match what the OPC server expects for an address. What is the complete message from the computer hosting the PI-OPC interface? You showed "AddItem failed" but what comes after that?

            • Re: Digital PI Point showing "Configure"
              nkrstic@kockw.com

              Hello Steve,

               

              For the same batch of added tags we are getting two different msgs;

               

              AddItem failed for TAGNAME type VT_I2: The requested data type cannot be returned for this item (c0040004)

              AddItem failed for TAGNAME; type VT_I2: The ItemID is not in the server address space (c0040007)

               

              Usualy this points to Tag configuration but we crosschecked the same even restarted the client side.... same results...

               

              Those are ALL digital tags....

                • Re: Digital PI Point showing "Configure"
                  nkrstic@kockw.com

                  We have cross-checked the instrument tags and they all look OK.

                    • Re: Digital PI Point showing "Configure"
                      pmackow

                      1. Did you try to read the tag value manually, using PI OPC Client?

                      2. Create a temporary tag of type String and try to use it to read the data. If the OPC Server returns something, it should be there.

                      1 of 1 people found this helpful
                        • Re: Digital PI Point showing "Configure"
                          nkrstic@kockw.com

                          Hi Pawel,

                           

                          Yes we can see data in OPC with a quality of GOOD. Example Value 33181 quality good.

                           

                          Equipment manufacturer provided the lookup table with more than 32K rows values. Which we know in digital state table is impossible to do in PI because of number of rows limitation in the digital table, because of that manufacturers of equipment provide a lookup table with smaller numbers. The digital state will loop thru the digital state table once you pass the digital table threshold explained below and tested in PI!  Controllers can send a number 33181 or 413 Digital state table has 7732 rows in our case because we use the small values ( short lookup).

                          Example PI receives a value of 33181

                          33181 -32768= 413 this provide the proper msg to the user.

                           

                          Concerns are the digital tags created in PI have an AUTO on SPAN by PI which is the number of rows in the digital state table which in our case is 7732. Will the PI or the interface mark a value as bad or configure if we get 33181?!

                           

                          Regards,

                          Nebojsa

                      • Re: Digital PI Point showing "Configure"
                        Steve Boyko

                        AddItem failed for TAGNAME type VT_I2: The requested data type cannot be returned for this item (c0040004)

                        This is a mismatch between the PI tag type and the data type that the OPC server is sending. As Pawel Mackow suggested, try a temporary PI string tag and see if it reads it.

                         

                        When PI reads a digital tag, it is reading an integer as an index into the digital state table for the PI tag. I would not recommend trying to directly apply that to the System table and rather do what Pawel suggested, read it into an Int32 tag and then use a calculated tag to map it to the right digital state in PI.

                         

                        AddItem failed for TAGNAME; type VT_I2: The ItemID is not in the server address space (c0040007)

                        This means the instrument tag address isn't matching anything in the OPC server.

                        1 of 1 people found this helpful
                          • Re: Digital PI Point showing "Configure"
                            nkrstic@kockw.com

                            Hi,

                             

                            Simply amazing that the digital state can't handle and interface are unable to handle this! They would if the sequence would not be mandatory to be maintained 1,2,3,4,5,6 but 1,4,6,7,9...in the digital state or the interface doesn't look at the SPAN. All of our states are +/- 9K it comes out to above 44K when we add all the empty non used ones like ?444..  on top of that to work around we should use one more pi point, common this is PI we are talking about.

                            The digital state table does handle the loop it is just to slow and can accept so many rows the Interface creates the major issue as well.

                             

                            Really such issues are a total turn off, PI System must cater for cases like this, we are not talking about small unknown manufactures but giants like GE, Baker... Schlumberger. This should fixed ASAP, proposed for development.

                             

                            We have found a way around this but, we should not have had to do all that with a system like PI..

                            Nebojsa