Sep 12, 2012

OPC Tunneling with OPC Unified Architecture (OPC UA)

Posted by Erik Dellinger

For most businesses, data consolidation, sharing, and visibility across the enterprise is a top priority. OPC Classic enabled many organizations to achieve these objectives. However, there have been several obstacles caused by limitations in the Microsoft Component Object Model (COM) and Distributed Component Object Model (DCOM). Despite being widely adopted, these two options are limited in the usability and security options required by today’s industrial automation and distributed operation environments.

The Latest and Most Capable OPC Specification

Although there are a number of proprietary solutions that can be used, all of them come with inherent challenges because they do not represent a widely adopted industry standard. Fortunately, OPC Unified Architecture (OPC UA), the latest generation of OPC, is rapidly becoming the “go to” standard. It provides a reliable cross platform framework for accessing real-time and historical data and events. It also enables secure communications of remote connections.

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Kepware believes OPC UA is the most capable OPC specification for interoperability between automation software and hardware products. It unifies previous OPC Classic specifications and incorporates data encryption with RSA standards and authentication based on the x509 Certificate standard. It’s also firewall friendly, and allows communications within local automation environments, across the enterprise, and through public network segments with high security and performance.

Kepware acknowledges OPC UA’s advantages, and has leveraged the OPC UA Client Driver and the free OPC UA Server interface for KEPServerEX to provide a powerful OPC tunneling solution. The OPC UA Client Driver for KEPServerEX provides communications to any OPC UA server, allowing data to be transferred securely and reliably. Because KEPServerEX is both an OPC Classic and an OPC UA server with both OPC DA and OPC UA Client Drivers, it eliminates the reliance on Microsoft COM and DCOM technology. This also enables OPC Classic implementations to utilize the latest OPC UA technology.

Real World Applications

Kepware clients have already benefited from the adoption of this new standard. The Municipal Wastewater Treatment Facility for the City of Orlando, Florida required a firewall-friendly, cross-domain communications technology that interoperated with existing OPC Classic systems. After evaluating a number of options, the city chose KEPServerEX, the OPC DA Client Driver, and the OPC UA Client Driver to provide secure, bi-directional data access between multiple municipality SCADA systems.

Download Kepware's City of Orlando Case Study