OPC Unified Architecture

OPC UA provides a single, secure, and reliable cross-platform framework for accessing a variety of data. In OPC “Classic,” each protocol is its own standard with no relation to or compatibility with one another. Services (read, write, etc.) unique to each protocol are used to access unique data within each model. With OPC UA, services are abstracted from the information models they can access. Client applications programmed to be aware of the information model they want to access can use a common set of services to obtain the data.

First released in the mid-1990s, the original OPC standard abstracted PLC-specific protocols (such as Modbus, DeviceNet, etc.) into a common API allowing HMI/SCADA systems to interface with “middleware” that would convert generic OPC read/write requests into device-specific requests. The technology took hold, and an entire industry of products emerged that allowed systems to be implemented using best-of-breed products seamlessly interfacing via OPC. First iterations of the OPC standard were restricted to Windows operating systems, and thus the acronym OPC was derived from “OLE (object linking and embedding) for Process Control.” The OPC Classic specifications, as they are now known, have been widely adopted across multiple industries. As manufacturing systems and organizations evolved, industries faced new challenges, including security and data contextualization. The OPC Foundation developed OPC UA to address these needs and to provide a feature-rich, extensible platform that was scalable and future-proof.

Kepware is the industry leading connectivity platform, providing a single source of industrial automation data to across applications. For enterprises that need to bridge the gap between different OPC UA servers, the new OPC UA Gateway facilitates streamlined data flow, enabling namespace aggregation, federation and securing of structured data throughout the enterprise, exclusively configured via Kepware+.

The OPC UA specification facilitates the interoperability and information exchange required for successful Industry 4.0 efforts. Its ability to provide modern, secure cross-platform data exchange, coupled with support for client/server and pub/sub messaging types, creates an opportunity for diverse network topologies and application stacks. Its support for standard and custom information models allows an organization to provide structure to unstructured data as close as possible to the systems generating the data in the model and format that best fits the organization’s unique needs.