What is OPC?
OPC is the interoperability standard for secure and reliable information exchange in industrial automation and the enterprise. The original OPC specification was developed in the mid-1990s by a group of automation industry vendors to standardize data exchange between software applications and industrial automation hardware devices.
The OPC specifications define an interface between clients and servers, and servers-to-servers, so system components like PLCs, HMIs and any OPC-aware device can share data without having to develop custom software device interface applications.
Why is OPC important?
The OPC standard brings plug-and-play connectivity to industrial automation. Before OPC, application vendors had to develop custom software for every third-party device and application that needed to be integrated into the automation system. With OPC, you get open connectivity across products, independent of your hardware or software platform. OPC defines the standard way for sharing real-time data, historical data, and alarms & events, reducing your integration and total life cycle costs for system implementations.
What are the OPC technologies?
The two primary technologies that comprise the OPC standards are OPC Classic and OPC UA (Unified Architecture).
OPC Classic is the original architecture, first released in 1996, based on Microsoft Windows technology, using COM/DCOM (Distributed Component Object Model) which was the Microsoft standard for software application communication.
OPC UA integrates all the functionality of the existing OPC Classic specifications into a single service-oriented architecture, while adding new features to OPC, such as platform independence, complex information modeling, security, and reliability.
What is OPC UA?
As the next-generation of OPC technology, OPC UA (Unified Architecture) is a major leap forward for secure, reliable and platform independent interoperability. OPC UA is designed for the transport of data and information from first-tier factory and process control devices through to the enterprise information system.
The OPC UA specification, first released in 2008, integrates all the functionality from the existing OPC Classic specifications into a single service-oriented architecture. It adds essential new features, such as platform independence, diagnostics, discovery, rendering of complex information models, security, and reliability. Additionally, OPC UA was released as an IEC Standard, IEC 62541 in October 2011.
OPC UA provides a single set of services for the OPC data models, such as Data Access, Alarms & Conditions, and Historical Access and can be implemented on non-Microsoft systems, including embedded devices.
OPC UA provides services for simple / complex information models of vendors and consortia to be “plugged in” to the address space of OPC UA. This information modeling feature allows generic software applications to browse, read, write and subscribe to a whole new world of information.
What is OPC Classic?
The OPC Classic specifications are based on Microsoft Windows technology, using COM/DCOM (Distributed Component Object Model) for communication among software components in a distributed client-server network. The OPC Classic specifications provide separate specifications for exchanging process data, alarms and historical data.
The original OPC Classic specification is OPC DA (Data Access), which defines an interface between client and server applications to exchange process and manufacturing data. Other important OPC Classic specifications include OPC Alarms & Events (OPC AE) and OPC Historical Data Access (OPC HDA).
OPC Classic continues to be an integral part of the OPC technology portfolio. In 2010, OPC Classic was enhanced with the OPC .NET 4.0 specifications to adapt to the new technical innovations of the Microsoft platforms providing better connectivity, reliability, security and interoperability.
What is the OPC Foundation?
The OPC Foundation is the world’s leading community for interoperability solutions developing and maintaining OPC specifications that deliver secure reliable interoperability.
The mission of the OPC Foundation is to:
- Provide an international infrastructure to facilitate users, vendors and consortia to cooperate together to develop standards for multivendor, multiplatform, secure and reliable interoperability in industrial automation
- Develop, maintain and bring to market the specifications for the OPC standards
- Certify member products
The OPC Foundation is dedicated to providing the best specifications, technology, and product certification.
Supplier members are provided a complete infrastructure to rapidly develop quality OPC certified products.
End-user members gain access to myriad of technical information and innovation to be able to successfully use the OPC technology and OPC products from the OPC Foundation community to easily be able to assemble complex complete automation system/solutions.
Who are the members of the OPC Foundation?
More than 450 companies who develop, promote and use OPC technology make up the OPC Foundation. Members, who include technology providers, end-users and organizations such as universities and researchers, work together to provide the best and most widely used connectivity standards available.
All OPC Foundation members are listed with a company profile in the official OPC Foundation Member Directory.
Why should I join the OPC Foundation?
By joining the OPC Foundation, your company can influence how OPC is developed and deployed into the future. Memberships include: Corporate (technology developers), End-users (technology consumers), and Affiliate members. Members can participate in the OPC community by joining technical working groups and participate in ongoing specification development.
All members are listed in the OPC Foundation Member Directory—with company profile and contact info—and can display the OPC Foundation Member logo. Corporate members can list their products in the OPC Foundation Product Directory and have complete access to all the OPC specifications (released and under development), reference technology implementations, and the OPC Certification Test Tools.
What is the OPC Foundation Certification Program?
The OPC Foundation Certification Program (developed and maintained by the OPC Foundation) provides the infrastructure, tools and processes to facilitate OPC Foundation members in the development of products that conform to the OPC specifications and interoperability requirements. The OPC Foundation Certification Program assures end-users that products from OPC Foundation members meet and exceed user expectations for plug-and-play, secure and reliable interoperability.
OPC Foundation-sanctioned Test Labs provide independent, objective and highly competent verification and certification testing, using a variety of tools and testing techniques that simulate real-world use. To become certified, a product must pass all tests, including Compliance, Interoperability, Robustness, Best Practices and Usability.
Once a product has been certified, the vendor will receive a “Certified” Logo for use only with the product that has passed the certification tests. Vendors displaying the Certification Logo must abide by the Logo License Agreement.
What resources are available to learn about the OPC technology?
The OPC technology has literally thousands of vendors that have brought quality OPC products to market. End-users have successfully been able to use OPC to achieve multi-vendor interoperability throughout industrial automation.
The OPC Foundation provides a comprehensive list of resources for both suppliers and end-users. The OPC Foundation resources for suppliers include the OPC specifications, reference implementations of the technology, quality developer documentation, and a complete certification program. The OPC Foundation also provides a repository of information about member companies inclusive of products and services to rapidly develop OPC products. Additional information including articles, white papers, books and webinars is also catalogued as resources on the OPC Foundation website.
The OPC Foundation resources for end-users includes the OPC specifications, the OPC Foundation product catalog (identifies all supplier member products and services), and a complete one-stop reference of information about OPC (which includes application success stories).