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How to transfer string data from PK750 Controller

We have a new DeltaV system with version 14.3 PK750 controllers. I am also using Beijer iX developer software to intregrate some Beijer x2 pro 10 HMI's to the system.

We want to display string, floating point, integer, and binary data on the HMI from the PK750 controllers using OPC UA. Using the Beijer developer tool, I can see the all types of tags in the controller such as floating point, integer, and binary data. However, I can see string data in the controller.

Is the PK750 controller restricted from transmitting string data over OPC UA or Ethernet to other systems such as HMI's or PLC's?

I have attached screenshots of the Beijer navigation tool and the DeltaV screens.

In the screenshots, you will see these parameters:

NAME                    TYPE                              VALUE

BATCHID               STRING                         "itworked"

TESTBATCHID     STRING                          "testbatchid"

TESTNUMBER      FLOATING POINT         3.1414

The screenshot "OPC_DATA_DEVELOPER_28DEC20" shows the Developer navigation tool before I added the TESTBATCHID and TESTNUMBER parameters, but it did show the TESTNUMBER parameter. I could display the TESTNUMBER value on the Beijer HMI as 3.1414.

Cornell

21 Replies

  • Cornell
    In the DeltaV Books online, in the topic "DeltaV OPC UA supported data types", it shows "DeltaV OPC UA allows the reading of strings. Writing strings is not supported. EIOC and workstation OPC UA clients support a maximum of 10 string signal inputs (reads) per LDT. "

    Does "reading" mean that the controller can read strings sent to it, or does it mean that the controller allows strings to be read by external devices?
  • AdrianOffield

    In reply to Cornell:

    If you use OPCWatchit (DeltaV OPC browser) you should find the string tags listed. It appears to be a shortcoming of the OPC interface in Beijer iX software not allowing you to select strings.

    DeltaV presents controller data to a software layer which is then made available in OPC and DeltaV Operate, reading means read by external systems (OSI pi historian for example), 'write' is external data writing to DeltaV (using OPCWatchit you can write data into a control module parameter).

    If you create a named-set parameter, what does iX browser show?
  • Andre Dicaire

    In reply to Cornell:

    Reading and Writing are activities performed by a Client app. The PK controller provides an OPC UA Server. It does not read or write, but awaits requests from the client. The reference above applies to the OPC UA Clients, not the PK controller.

    The statement "writing Strings is not supported" appears to be in the context of the OPC UA Clients. The OPC DA server allowed read and writes to be performed by OPC DA Clients. The OPC UA server is a Wrapper that exposes the three traditional OPC servers (DA, HDA and A&E) to OPC UA clients. I would expect that writes to the OPC UA server are permitted as these would pass to the OPC DA server (Writes are not permitted via OPC HDA and A&E Servers). The PK controller has an OPC UA server, which should accept writes. However, I can't confirm this as I don't have a setup with OPC UA client to PK. I'll ask some colleagues that have used the Bejier HMI with PK standalone.

    Andre Dicaire

  • Andre Dicaire

    In reply to Andre Dicaire:

    I found some additional information that confirms the DeltaV OPC UA Servers (App station and PK controllers does support Strings and an OPC UA Client can write to them, if the Client supports this. The Books On Line limitation on Writing to Strings applies to the OPC UA Clients found on DeltaV workstations and EIOC.

    However, I also found a set up document for the Bejier HMI from our project team where they found that the Bejier OPC Client did not support string data types. In this case, it may be a limitation of the Bejier OPC UA Client, which is similar to the DeltaV OPC UA Client.

    A CTS call indicated that OPC UA Writes to the DeltaV OPC UA Server were successful using a Test Client from Integration Objects. I would suggest you download a test client to confirm the PK controller String parameters can be read and a written to by an OPC UA Client.

    Andre Dicaire

  • Cornell
    Andre,
     
    Thanks for the information. Today we tested the Beijer iX developer navigation tool and a Matrikon OPC UA explorer tool.
     
    If we create a “String” type parameter in DeltaV, both the Beijer iX developer navigation tool and a Matrikon OPC UA explorer tool will not show the parameter. If we made the parameter a named set type, both tools would show it as an integer value and display the parameter. But as soon as we change the parameter back to a string type, the two tools would not be able to see the parameter in DeltaV.
     
    I will try the Test Client from Integration Objects.
     
    Cornell Chandler, P.E.
    Grifols Engineering
    Principal Engineer
    Grifols Shared Services NA
    (P) 919-359-4370 (F) 919-359-5815
    8368 U.S. 70 West Business Highway
    Clayton, NC 27520, USA
     
     
  • Cornell
    Andre,
     
    Good morning.
     
    I installed an OPC UA client from Integration Objects and I see the same result. I can transfer numeric parameters to an OPC UA client, but not string type parameters.
     
    Here is a screenshot of the Integration Objects client. Note that the “TESTBATCHID” and the “BATCHID” string parameters do not show in the client:
     
    Here is the online view from DeltaV:
     
    Cornell Chandler, P.E.
    Grifols Engineering
    Principal Engineer
    Grifols Shared Services NA
    (P) 919-359-4370 (F) 919-359-5815
    8368 U.S. 70 West Business Highway
    Clayton, NC 27520, USA
     
     
  • Andre Dicaire

    In reply to Cornell:

    That is consistent with what our project team experienced, though the GSC call I reviewed indicated the OPC UA server did support strings.  Then again, that could have been limited to the Application station wrapper and was not meant to include the PK controller OPC UA Server.  

    I can only suggest you log a call with the GSC to raise this issue, as well as to get clarity documented in the database.  This will also confirm to you how to proceed, which for now seems to be to use Named Sets with equivalent enumerations in the Bejier database.  

    It is curious why the OPC UA clients are prevented from writing strings and the OPC UA Server on the PK does not allow access to string parameters.

    Also, the document I found indicated that Scaling Parameters were supported.  These have 4 fields:  EU0, EU100, Units and Decpt.  The Units field is a string.  Well actually, it is an integer that maps to a defined string.  If you read the PV_SCALE.UNITS, I expect you will see a number.  You should find a file in /DeltaV/DVDATA/Download called EUDT.SCR.  This contains an enumeration of all EU Units.  The value for % is 1342.  If Bejier receives the integer, you can look up and create an enumeration and include all the values your configuration will be using.  

    I don't think I can help you any further as I have not used the PK OPC UA server to date.  Good Luck.

    Andre Dicaire

  • Cornell
    Andre,
     
    Thank you very much for your assistance.
     
    Cornell Chandler, P.E.
    Grifols Engineering
    Principal Engineer
    Grifols Shared Services NA
    (P) 919-359-4370 (F) 919-359-5815
    8368 U.S. 70 West Business Highway
    Clayton, NC 27520, USA
     
     
  • Andre Dicaire

    In reply to Cornell:

    Cornell, You're welcome. A friend confirmed to me that the String support is in the App Station OPC UA server, but is not in the PK server. This is being looked at, but you'll have to proceed without access to String parameters for now. As GI Joe says, "Knowing is half the Battle."

    Andre Dicaire

  • AdrianOffield

    In reply to Andre Dicaire:

    Interesting to know PKs have differing feature set compared to regular DV. Is that still the case if integrated into a fully licensed PRO+?

    With the PK solution, can you still create CMs on PRO+ station that would bypass this limitation?
  • Cornell
    Andre,
     
    Yes, knowledge is power. It does seem that Books On Line gives the incorrect impression that String data is supported by the PK controller OPC. That should be corrected.
     
    Cornell Chandler, P.E.
    Grifols Engineering
    Principal Engineer
    Grifols Shared Services NA
    (P) 919-359-4370 (F) 919-359-5815
    8368 U.S. 70 West Business Highway
    Clayton, NC 27520, USA
     
     
  • Cornell

    In reply to AdrianOffield:

    OPC Watchit does show string values. We tried a nameset parameter, but it only showed the numerical equivalent of the string in the nameset in the Beijer software or Matrikon OPC UA test tool.
  • Lun.Raznik

    In reply to Cornell:

    If you wanted to read Named sets as string you have to tell the client to request a string data type otherwise it will default to int. See example below using Matrikon Explorer.

  • Andre Dicaire

    In reply to Cornell:

    OPC Watchit connects to the OPC DA server. It does not use OPC UA. The OPC DA server supports strings, but is not available on the PK Controller itself. It is only available at the workstation. Note that the String should also work on the workstation OPC UA server. The PK OPC UA server is where the issue lies, and OPC Watchit does not connect to this server.

    Andre Dicaire

  • AdrianOffield

    In reply to Andre Dicaire:

    Hi Andre, just to clarify are you stating PK controllers do not use OPC DA, PK controllers only provide OPC UA connections?

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