Query regarding Failure in OPC UA communication between ROCKWELL DCS and LabVIEW

[aryadeo]

Issue:

• The LabVIEW application created by us has multiple nodes IDs set for data communication with the DCS of the plant (DCS Model: Allen Bradley 1756-L75/B).
• LabVIEW OPC UA toolkit is used to create the Node IDs set for bidirectional communication.
• The Node IDS created for OPC communication in LabVIEW used OPC UA protocol, whereas, the plant DCS is based on OPC DA protocol.
• As the Plant DCS works on OPC DA protocol and unable to get linked with the Node IDs set by the LabVIEW application.

Technical Specification:

• Details of installed SCADA software: FactoryTalk View, V:11
• Installed Windows OS for Server & Client: Windows Server 2016 & Windows 10 Professional
• LabVIEW Version used for development: LabVIEW 2018
• Toolkit used: LabVIEW OPC UA Toolkit
• Number of OPC IDs created: 14 (8 for sending data ad 6 for receiving purpose)
• Type of variable used in Node IDs: 1D array of double datatype

Attempts made:

• KEPServerEX is used for node creation and data sharing in the client system.
• Nodes with similar data type are created in the KEPWARE OPC server. But no ACTIVE status is shown in the TAGs created for data sharing.

Queries:

• What is the procedure to be followed for conversion of the OPC UA protocol into OPC DA protocol?
  • Is there any provision available in LabVIEW for the same? We have tried data sharing using “Datasocket Connection”, but the performance is not satisfactory.
  • What are the drivers required to make the data sharing status as ACTIVE in the tags created in KEPWARE server?
  • Whether there is any driver made available by NI for data sharing. If Yes, then how it can be availed?
  • Is there any other way available in NI LabVIEW to create Node IDs for data communication using OPC DA protocol?

If possible, please assist in resolving the issue.

Thanks for the Support.

[Sebastian.Weber]

Hi!

OPC UA is the successor of DA, and has been completely re-developed from scratch. For example, it bases on TCP communication instead of DCOM, which allows servers and clients to run on different network devices. Both protocols do basically  the same, they address values by names and allow to get notified on value change, but technically, they are completely different. There is no way to use an UA client on a DA server or vice versa.

I see two solutions:

1. There is software out there which acts as OPC DA client and UA server or v.v., and passes the data between the two worlds. For example, Softing Datafeed allows for this.
2. For LabVIEW, there is the Datalogging and Supervisory Control Module, which seems to be the correct software package to use OPC DA within LabVIEW. Personally, I never used OPC DA with LabVIEW, only OPC UA. So check if this is the right package for you!