OPC to launch unified architecture

The OPC Foundation (OPCF) has joined the international cooperative team of the three leading fieldbus organizations, the Fieldbus Foundation (FF), HART Communication Foundation (HCF), and PROFIBUS Nutzerorganisation e.V. (PNO), to extend the reach of electronic device descriptions (EDDs) into the OPC unified architecture.

By Jack Smith, Senior Editor, Plant Engineering Magazine March 10, 2005

The OPC Foundation (OPCF) has joined the international cooperative team of the three leading fieldbus organizations, the Fieldbus Foundation (FF), HART Communication Foundation (HCF), and PROFIBUS Nutzerorganisation e.V. (PNO), to extend the reach of electronic device descriptions (EDDs) into the OPC unified architecture.

In 2003, FF, HCF, and PNO formed a cooperative joint working group to extend the capabilities of electronic device description language (EDDL). An underlying technology in millions of installed field instruments, EDDL is a text-based language for describing the digital communication characteristics of intelligent control devices. Device suppliers use EDDs to provide information on parameters and other data in a device.

The joint working group developed extensions that enable robust organization and graphical visualization of device data, and provide support for persistent data storage, while maintaining operating system (OS) and platform independence. The extensions will be integrated within the respective control network technologies and added to the IEC 61804-2 standard upon completion. Following its successful Phase 1 collaboration, the joint working group has begun efforts to further extend the open and interoperable EDD standard for delivery of extensive device, control configuration, and diagnostic data to the OPC unified architecture.

According to ARC Advisory Group analyst Larry O’Brien, the automation community has long speculated on the role that OPC would play in the context of FOUNDATION fieldbus. “The inclusion of EDD in the OPC framework is a smart move that will enhance interoperability significantly at the system and enterprise level in a truly open fashion that is independent of any operating system architecture,” said O’Brien. “EDD also provides OPC with a technology that is an accepted part of the IEC fieldbus standard and is already embedded in millions of FOUNDATION fieldbus, HART, and Profibus devices and systems that are installed in the field and running today.”

Fieldbus Foundation President and CEO Richard Timoney said, “Phase 2 of this agreement will continue to enhance the delivery of critical data from the device, and provide a standard and consistent structure for data transport within the OPC unified architecture. The overall effect will be a vastly simplified approach for users to access and distribute performance measurements and process data such as alarms. Users will also take advantage of increased system interoperability and cost-effective control system integration.”

According to Tom Burke, OPCF president, users will benefit most from the interoperability of the OPC unified architecture. “This is the beauty of working with standards like OPC and EDDL. Users can take advantage of open systems, but be assured of connectivity and interoperability among these systems,” said Burke. “Without this standards-based approach, the industry would have to create a community of software developers to support all the different systems, each with a unique set of software drivers and the associated revision management issues that are part and parcel of operating system changes.”

OPC unified architecture

The OPC unified architecture has been under development for the past 18 months by a team of OPC foundation members. OPC unified architecture specifications are expected to be unveiled soon. This unified architecture promises to bring forward and tie together the existing OPC technology that has been developed over the last 10 years to an integrated platform that migrates the DCOM architecture to a web-based architecture.

The OPC unified architecture melds current OPC funtionality in the form of separate COM specifications into a unified set of base services for secure reliable interoperable transport. The OPC unified architecture provides the foundation to transport data/information independent of the content. This provides a tighter coupling of the different types of data exposed via OPC and eliminates redundant coding by OPC software vendors that previously needed to support multiple OPC COM interfaces. The OPC unified architecture then goes beyond providing the transport layer for data/information, to include the development of services that support reliability and transaction-oriented information processing.

The OPC unified architecture is designed to take the existing OPC products built on the DCOM based technology and transparently have adapters that allow OPC unified architecture applications to work on a seamless fashion with OPC DCOM based applications.

DevCon 2005

The 2005 OPC Unified Architecture Developer Conference (OPC UA DevCon) will be held and sponsored by Microsoft and OPC on April 19-20, 2005 at the Microsoft campus in Redmond, WA. The purpose of this event is to provide a technical overview and jumpstart of the OPC unified architecture and the corresponding Microsoft technology.

Some of the events at the conference include:

  • OPC unified architecture/Microsoft technology demonstration

  • OPC for automation

  • Migration of OPC DCOM-based products to the OPC unified architecture

  • OPC unified architecture technical sessions

  • Panel Discussions featuring OPC and Microsoft developers, and OPC end-users.

    • Attendees will have the opportunity to get a behind-the-scenes look and meet the developers of the OPC unified architecture and the Microsoft staff. Users benefit by gaining knowledge and understanding about how OPC unified architecture affects the automation in their plants.

      Background of cooperative team members

      The OPC Foundation exists to ensure interoperability in automation by creating and maintaining open specifications that standardize the communication of acquired process data, alarm, and event records, historical data, and batch data to multivendor enterprise systems and between production devices. Production devices include sensors, instruments, PLCs, remote terminal units, DCS, HMI, historians, trending subsystems, alarm subsystems, and more as used in the process industry, manufacturing, and in acquiring and transporting oil, gas, and minerals. OPC builds on existing computer industry standards.

      The Fieldbus Foundation was established in September 1994 by a merger of WorldFIP North America and the Interoperable Systems Project (ISP). The foundation is a nonprofit corporation that consists of more than 350 suppliers and end users of process control and manufacturing automation products.

      HCF is an independent nonprofit organization, and is the owner and standards setting body for the HART Protocol. Established in 1993, it provides support for application of the protocol and ensures that the technology is openly available for the benefit of the industry. Rosemount originated the HART protocol in the late 1980s. HART is an acronym for “highway addressable remote transducer.” The protocol was “open” for other companies to use and a user group formed in 1990, which became HCF three years later.