Emerson Exchange 365

Establishing Pi Historian Communication with DeltaV

Hello, 

I currently have Pi server and DeltaV communicating with each other via OPC-DA.

I can add DCS tags in Pi database and everything works fine. Right now Pi and DCS communication is setup such that data from DCS is sent to Pi for display on Pi application. 

Now, I need send data from Pi Server to the DCS to show certain Pi data on the DCS graphic. 

Do you know how I can set this up please?

Thanks,

DCS Newbie

• 19 Feb 2019 3:03 PM
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9 Replies

• PRASHANT-MUTTEPAWAR

  

  • 19 Feb 2019 5:03 PM

  Hi
  
  i think their is option for the communication in opc- da for single direction or multiple direction.
  
  Regards
  
  Prashant .

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• Neil Wang

  

  • 19 Feb 2019 5:28 PM

  Hi there,

  A lot of detials need to be explored for this reqeust. I shall touch some just on the surface.

  If you need to just display the realtime values, i.e. you do not need to see the historical values or trends, then you may consider using OPC. Either OPC Mirror or OPC UA can connet to a Pi Server that functions as OPC DA or UA Server, and get values from that Pi server. For this architecture, you will need an additional Application Station node with needed licenses, and you will also need the proper OPC Server functionalities on the Pi side.
  
  Once the data are landed in DeltaV, you may choose to historize the data using the 250 tags complimentary historian inside of every DeltaV workstation or a dedicated DeltaV Continuous Historian (DVCH) node. But please notice that the time stamps of historical values done this way are assigned by DeltaV, so are not the orginal time stamps on when those values were actually generated.
  
  If you need to display historical values or trends, DeltaV has a semi-programatic way to write external data into DVCH. You may look for "OPC write interface to the DeltaV Continuous Historian" in Books Online for more details. This method reqeusts some coding work using C++. A sample client is provided to facilitate the coding work.
  
  Another unofficial, theoretical way for displaying historical values in Pi is to use DeltaV clients, e.g. DeltaV Live Chart, DeltaV Operate Embedded Trend Chart, or Process History View, to directly connec to the Pi server. This way, you will need to setup the trust between DeltaV and Pi domains, and then create proper user mapping between DetlaV and Pi users. After the security is done, you may try typing in the exact data path/structure, e.g. ServerName.ModuleName.PerimeterName.Value, to query the values. You may look for "Configure security options for OSIsoft PI Server" in Books Online for more details. Again, this is an untested and theoretical way, but it does not need you to purchase additional things. Try with caution.

  Neil Wang

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• Andre Dicaire

  

  • 19 Feb 2019 5:30 PM

  The data you wish to display must be "landed" into a DeltaV Module, and this module should be assigned to the Application station hosting the OPC DA server. Think about how you want this data structured. You can place all the data in one module or create multiple modules. In this module, you create Parameters of the same data type as the day you are writing from PI.
  
  Download the modules. You can assign these parameters to DeltaV displays or referenced them with external references in any module as needed. Then you set up your PI server to write to these modules. They will show up in the OPC Browser.
  
  The reason that you assign these modules to the OPC server is that continuous OPC DA writes should only be done to a local module on the Application station. Continuous writes to a module located in another Node (controller) result in excessive level of writes and begin to starve the controller of CPU required for execution of control functions. By landing the data in the App station module, it can be used anywhere using normal Read functions via external references or datalinks.
  
  Build your landing modules for the data, then you can populate these parameters as needed, and display/reference them anywhere in DeltaV.

  Andre Dicaire

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• Andre Dicaire

  

  • 19 Feb 2019 5:45 PM

  In reply to Neil Wang:

  Neil, you've laid out a few options, but the original message indicates they already have an OPC DA server sending DeltaV Data to PI. So they do not need an "additional Application stations".
  
  They do need a Module in which to place the incoming data from PI in order to display it on the Operator station. So a landing module is needed. If the data is in the landing module, normal DeltaV history collection allows them to place this into the DeltaV Historian, rather than using the Historical Data Entry.
  
  We have not discussed the versions of DeltaV, but OPC UA is native in v14. previously, DeltaV offered OPC DA, and in v13 we have the OPC.NET wrapper. Today, users can obtain OPC UA wrappers for the Server and Client side applications. If setting up new connections, I would recommend moving to OPC UA if possible.
  
  The other complicating factor here is the ability for the PI server to actually reach the DeltaV Application station through the network layers. Sometimes, the PI OPC connector is placed in an intermediate computer to allow it to collect data through one firewall and send it to PI through a second firewall. If the PI server is running a PI Client, this client must be able to connect to the DeltaV OPC Server. If there are additional firewall layers, the acces to write the OPC data to DeltaV may require additional tools.
  
  The other challenge is that the PI collector that sends data to OSI PI is firewall friendly, using a single port. Running an OPC Client through a Firewall to an OPC server is a Firewall challenge.
  
  My advise to DCS Newbie is that if you are traversing firewalls, you should seek out some expertise from your local Emerson service provider, or data integration consultant familiar with OPC and OSI PI. There are additional Cybersecurity concerns that could likely restrict your options.

  Andre Dicaire

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• Neil Wang

  

  • 19 Feb 2019 7:36 PM

  In reply to Andre Dicaire:

  Hi Andre,
  
  Thanks for the additional comments. Agreed that based on the limited information, OPC DA seems to be the best fit option among the several ones that DeltaV supports.
  
  Regards,
  Neil

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• John Rezabek

  

  • 20 Feb 2019 2:01 PM

  

  This is what we do. Check the manual - I think location 3 is the key setting. On the first tab, set the source tag to the PI point . . .

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• DCS Newbie

  

  • 21 Feb 2019 3:29 PM

  In reply to Andre Dicaire:

  Andre Dicaire said:

  
  
  They do need a Module in which to place the incoming data from PI in order to display it on the Operator station.

  Thank you Andre Dicaire, 

  This is exactly what I need. 

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• DCS Newbie

  

  • 21 Feb 2019 3:31 PM

  In reply to John Rezabek:

  John Rezabek said:

  

  This is what we do. Check the manual - I think location 3 is the key setting. On the first tab, set the source tag to the PI point . . .

  Thank you so much John, 

  I can see this display in my Pi Management software.

  Can you please explain a bit more. What is OPC_VALERO mean? Where are you grabbing the data from AI22808.CV on your DeltaV?

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• John Rezabek

  

  • 22 Feb 2019 12:27 PM

  In reply to DCS Newbie:

  Like Andre said - OPC_VALERO is just a module we created in DeltaV to receive the "incoming" PI data. The parameter AI82808.CV is a parameter in the module - like a user-defined (internal read only) parameter under "special items". For the most part we are using "real" number parameters but we have a few string variables to receive "time and date" for example.

  You can put them all (one parameter per PI data point) in the same module and then just display them with a datalink. If you want to display on a faceplate you would need to create an individual module for each PI point you are sending back to DeltaV.

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