New Automation Concepts with OPC Unified Architecture

Jürgen Lange, Softing Industrial Automation GmbH

The OPC UA technology complements the traditional OPC industrial standard by adding important characteristics such as platform independence, scalability, high availability, and Internet capability. Many automation component vendors already offer OPC UA clients or servers for their PLCs, process control systems, field devices, or operator panels. An efficient and cost-effective way to develop conformant OPC UA products is to use OPC development kits like, for example, Softing's OPC UA toolkit.

OPC technology has evolved into a de-facto standard for interope- rable data exchange between multi-vendor software applications that is applicable in a wide range of industries spanning from manu- facturing and process industries to building automation and many others. Today more than 20,000 OPC products from over 3,500 different manufacturers are in use Fig. 1 . OPC UA allows multiplatform communication between all over the world. OPC facilitates applications the data transfer between widely distributed parts of a plant. The OPC interfaces bridge the divide ent versions of Windows and non- between heterogeneous automa- Standardized communication Windows operating systems tion worlds. (Fig. 1). OPC UA facilitates the secure,

With the introduction of the reliable, and manufacturer-inde- OPC UA provides a set of features platform-independent OPC Unified pendent transport of raw data and that allows the implementation of Architecture (OPC UA), OPC tech- pre-processed information from the new concepts for secure and nology has started to conquer new factory floor to the production plan- robust plant automation. They application areas, such as embed- ning or ERP system. The desired include: ded systems or the IT world. information is provided to any Recently, the new technology has authorized application and person, established itself in areas where anytime and anywhere. This func- ● Standardized communication OPC was hardly seen before, e.g. tionality is independent of the over the Internet and across device parameterization. The manufacturer that created the firewalls: reason for this breadth of appli- applications, the programming OPC UA uses a dedicated UA cation is that the OPC UA tech- language they were developed in, Binary protocol for data ex- nology offers extended features and the operating system they run change that is based on TCP; when compared to Classic OPC. on. OPC UA is no longer DCOM Web services and HTTP are also OPC UA's platform independence based, but uses a service-oriented supported. Only one port needs and, in particular, its scalability architecture (SOA). This makes to be opened in a firewall – that's opens up many possibilities for OPC UA easy to port. Today, enough. Integrated security new and efficient automation OPC UA builds a bridge between mechanisms guarantee secure concepts. the enterprise level with Unix Internet communication. systems and embedded automation components running differ-

Softing New Automation Concepts with OPC Unified Architecture © by VDE Verlag, etz, ed. 4-2011 Page 1 of 3 ● Protection against unauthorized data access: The sophisticated security concept provided by OPC UA technology ensures efficient protection against unauthorized access, sabotage, and faults caused by negligent use. OPC UA security is based on global standards developed by the World Wide Web consortium. It offers various possibilities to identify applications, authenticate users and protect against unauthorized access, as well as sign messages and encrypt the payload transferred.

● Data security and reliability: The communication standard defines a robust architecture with reliable communication mechanisms, configurable timeouts, automatic fault detection, and Fig 2 . OPC UA allows secure and robust “information permeability” recovery mechanisms. The – from the sensor to the ERP system communication link between a OPC UA client and server can be monitored by both the client and the server. If a connection is sensor, the event of excess tem- distributed and separated from temporarily interrupted, the data perature, and the historical aver- each other by firewalls without can be buffered in the server. In age temperature, OPC UA needs problems. security-critical areas, OPC UA only one component. This helps defines an additional redundancy to reduce configuration and Developing OPC UA based concept that can be used for engineering times. concepts devices, servers and clients. ● High performance: Many automation component ● Platform independence and OPC UA is based on a binary vendors already offer OPC UA scalability: protocol that is TCP-based. This clients or servers for their PLCs, Using service-oriented base very efficient protocol allows for process control systems, field technologies ensures that a fast data exchange that will devices, or operator panels. An OPC UA is platform independent meet the high-performance efficient and cost-effective way to and opens up many possibilities requirements of most applica- build OPC UA components is to for new and cost-effective auto- tions. The actual binary protocol rely on conformant OPC toolkits, mation concepts. Embedded implementation is available such as the OPC Toolbox UA field devices, process control through the OPC Foundation and (Fig. 3) from Softing [1]. This systems, PLCs, gateways, or serves as the basis for all software allows the quick and easy operator panels are developed OPC UA servers and clients. development of OPC UA clients using lean OPC UA server im- and servers for Windows, Linux, plementations that have been ● New application possibilities: VxWorks and other embedded ported directly to operating The wide breadth of the operating systems. OPC UA systems including embedded OPC UA technology allows im- specific functionality for creating, Linux, VxWorks, QNX, RTOS, plementing new vertical integra- browsing, and managing an and many more. tion concepts. By cascading OPC UA address space; for OPC UA components, informa- creating, deleting, reading, and ● Simplification by unification: tion can be transported securely writing OPC UA objects; for event OPC UA defines an integrated and reliably from the factory floor handling, method calls, and much address space and an informa- all the way up to the production more has been fully implemented tion model that maps process planning or ERP system (Fig. 2). in the compact OPC Toolbox UA. data, alarms, historical data, and For this purpose, OPC UA program invocations. In this way, enabled client and server com- With the toolbox, developers can even complex processes can be ponents at the automation level save several months of time and fully described with OPC UA. connect embedded UA servers reduce the time-to-market for their While classic OPC requires three at the field level with OPC UA products. different OPC servers – DA, AE clients integrated in ERP and HDA – with different seman- systems at the enterprise level. tics to acquire, for example, the The individual OPC UA compo- current value of a temperature nents can be geographically

Softing New Automation Concepts with OPC Unified Architecture © by VDE Verlag, etz, ed. 4-2011 Page 2 of 3 Fig. 3 . OPC UA toolkits comprising platform dependent and platform independent parts allow implementing OPC UA clients and servers on almost any target platform

Conclusion

The future IEC communication standard OPC UA provides Dipl.-Ing. Jürgen Lange is Market Segment Manager features that offer new possibilities at Softing Industrial Automation. He also represents of embedding an internationally the company at OPC Europe and at the Technical standardized communication Advisory Council of the OPC Foundation. interface in disparate systems ranging from PLCs, process control E-Mail: [email protected] systems, drives, gateways and operator panels to MES or ERP systems. The result is savings in installation, setup, commissioning, maintenance and operation. Com- munication structures can be simplified and vertical integration concepts consistently implemented. Toolkits like the OPC Toolbox UA allow the cost-effective and efficient implementation of OPC UA components under Windows and in embedded systems.

Bibliography

[1] Softing Industrial Automation GmbH, Haar, Germany: www.softing-ia.com