OPC UA - New Secure, Platform-Independent Standard Offers More Value

OPC UA - New Secure, Platform-Independent Standard Offers More Value

 
By Bill Lydon - Editor
 
I recently spoke with Roy Kok of Kepware to gain a better understanding of OPC UA. It is important with new technology to thoroughly understand its advantages so you can gain value and avoid misapplying it. Kepware, founded in 1995, has a great deal of OPC knowledge and knowhow as a leading supplier of OPC software. Kepware offers a very wide range of products for manufacturing, building automation, oil & gas, power distribution, water & wastewater, IT, utility, and infrastructure applications.
 
Bill: How will the new OPC UA affect existing applications based on OPC? 
Roy: OPC UA (Unified Architecture) is a new specification, leveraging new technology and delivers a new set of features not possible in OPC “Classic”.
 
Bill: Does OPC UA eliminate existing applications based on OPC? 
Roy: It is designed to co-exist, not replace.  Products of the past can continue supporting OPC Classic based on Microsoft COM and DCOM technology.  Gateway products will exist to enable OPC Classic servers to communicate via OPC UA.  New server products will likely have OPC Classic and OPC UA interfaces which can be used separately and in parallel, to supportcustomers that will have a combination of legacy and new client applications as they go forward.
 
Bill: What is a simple functional definition of OPC UA?
Roy: Very simply put, OPC UA (Unified Architecture) is the next generation of OPC Technology.  In addition to new benefits, OPC UA “Unifies” the OPC Classic specifications; OPC Classic is a collection of specifications including OPC DA, OPC AE, OPC HDA, and several others.
 
Bill: Microsoft Technology has always been the core of OPC, limiting hardware options. This is particularly true for embedded applications. Does OPC UA address this issue?
Roy: OPC UA is designed to be platform independent and operating system independent, supporting Windows, Linux, and a variety of Embedded Operating Systems.  There are a standard set of operating system independent communication interfaces (Stacks) developed by and managed by the OPC Foundation.  This enables OPC UA to be used in a very broad range of applications, from sensors to analytic equipment, HMI/SCADA and up to Enterprise applications.  It also enables OPC UA to cross into new markets including medical devices, automotive, the new Smart Grid and much more. 
 
Bill: How does OPC UA address data security concerns people have with OPC?
Roy: OPC UA has been designed to be secure with features including encrypted communications and identity certificates. OPC UA follows the RSA standards (algorithm for public-key cryptography (more information: http://en.wikipedia.org/wiki/RSA ) and leverages X509 standard security certificates (more information: http://en.wikipedia.org/wiki/X.509 ). The design meets the needs of wide area communications with the highest degree of security. Both 128 and 256 bit encryption is supported. Security is one of the greatest benefits of OPC UA and users can now create widely distributed information systems, even Internet based communications, knowing that security has been considered from the start and is at the core of the design.
 
Bill: How does OPC UA address the latest software trend, Service Oriented Architecture; SOA?
Roy: OPC UA leverages the latest in communications technology to deliver SOA capabilities and Firewall Friendliness.  System administrators are able to easily define and manage OPC UA communications through their enterprise with known ports and communication methods, TCP or http. Discovery services are included with the architecture enabling the discovery of OPC UA servers and associated capabilities through Profiles. For example, a simple device that only supports data transfer will self describe itself when interrogated. Client applications now have a standard mechanism for querying servers for the data types and capabilities they support.
 
Bill: The OPC data model was originally designed for sensing and control, limiting its abilities. Does OPC UA address the broader information required by the convergence of IT and automation?
Roy: OPC UA continues to support the simple data types of OPC Classic, but in addition, supports the transfer of information.  Information = Data + Context.  Context can come in many forms, from standards such as S95 to vendor specific data models.  The architecture of OPC UA enables it to support various models and be the standard communications interface across the industry, for use in supporting public data models as well as data models which are proprietary to an automation vendor. Of course, when used with proprietary models, OPC loses its benefit of industry interoperability. However, it is a very sophisticated standard delivering a great deal of benefit, even if used as a “Private Pipe” within an automation vendor product portfolio.
 
Bill: What are some other technical benefits delivered by OPC-UA?
Roy: OPC UA servers will advertise their capabilities through profiles, a mechanism by which clients may interrogate a server for its capabilities.  This enables vendors with different product capabilities to leverage the OPC UA data types and functions that make sense for them in a way that is easy to manage at the client side.  One of the greatest benefits associated with OPC UA is simply the departure from COM and DCOM technology.  In the past, distributed applications required the use of “Tunnel” products, which delivered a secure connection from one computer to another, for the delivery of OPC Classic data.  OPC UA effectively makes Tunnel products obsolete, as it is inherently reliable and secure in a distributed application.
 
Bill: Can I use OPC drivers with OPC UA?
Roy: The majority of driver companies will likely deliver drivers with an OPC UA server as an upgrade.  Older OPC “Classic” drivers will be supported with OPC UA through the use of a gateway product.  Kepware, for example, will be offering an OPC UA gateway capability in February of 2010.  Kepware will also be offering both OPC UA Server and OPC UA Client capabilities in its KEPServerEX product, enabling customers to take advantage of OPC UA communications as a Tunnel in distributed applications.
 
Bill: The trend in automation is better use of data to improve operations and efficiency.  What does that mean for drivers and interoperability technologies like OPC?
Roy: Drivers will become more intelligent in acquiring context from equipment, or creating context within the driver, for improved use in client applications.  Context can come from standardized tag names, equipment models, and collections of data, triggered at the source. For example, Kepware Drivers today are typically “Auto Configuring”, auto-generating the name space from information in either a program file or interrogated from the device itself. Going forward, OPC UA enables a great deal more sophistication in how “Information” if represented and transferred.
 
Bill: How does a user decide to apply OPC or OPC UA in an application?
Roy: In the future, as OPC UA servers and clients are more available, it will be the natural choice for any application, especially if there is a distributed component (communications across a network).  OPC UA is the next generation of technology and it will displace OPC Classic in time.
 
Bill: Do you see OPC applications using PCs in appliance form factors, sometimes called a blind node or PC brick?
Roy: An appliance form factor is available today and it is logical that more will be made available.  One example is the OLDI Universal Gateway appliance. While it is not yet enabled with OPC UA, that will come shortly. Today, it delivers our suite of Manufacturing protocols and is designed to address Machine to Machine (M2M) applications. OPC UA, combined with multiple protocols, allows easy linking of data from one set of tags to another on an appliance processor platform for a wider range of new M2M applications, while also supporting secure supervisory connections.
 
Bill: The world of drivers seems to be changing, from independent driver developers to a new world dominated by a handful of providers.  Why is this happening and what does it mean for the future of drivers?
Roy:  In the past, drivers were developed primarily by system integrators with OPC toolkits.  These drivers met the requirements of the application at hand.  Over time, some companies developed a significant enough number to be “A Driver Company.”  However, with the changing standards, changing operating systems, and changing hardware products, drivers require continuous development and maintenance that is an ongoing investment.  Few companies amassed a broad enough portfolio, and created a large enough reseller market to justify the continued engineering and ongoing support investment. 
 
Bill: Why has Kepware been successful?
Roy: Kepware has and continues to make significant investment in OPC and driver development and support to offer solutions to meet industry needs.   Kepware currently supports over 140 protocols to more than 100,000 applications per year.  In addition, Kepware is partnered with over 50 automation vendors including hardware vendors endorsing Kepware drivers for their products, clients serving the HMI/SCADA, Historian and Enterprise applications.   We set high standards for Kepware products to deliver high quality, high performance, reliability, and ease of use.
 
Kepware delivers both industry standard client interfaces like OPC Classic and OPC UA, AND, Kepware delivers vendor preferred interfaces for companies like Oracle, Wonderware and GE Fanuc. 
 
More Information:
OPC Foundation: www.opcfoundation.org
Kepware: www.kepware.com
Online Development: www.oldi.com