Collecting data for analytics and optimization of the process is promising new business models. But how does the sensor, the wind turbine or the automation world in general talk to the IT world, like the Azure cloud from Microsoft or the MES product from SAP?

The IEC62541 communication standard OPC Unified Architecture (OPC UA) considerably simplifies and standardises the integration of any kind of device – that’s why it is set in the Reference Architecture (RAMI4.0) of Germany’s Industrie 4.0.

Dream?

It would be ideal, however, if all devices and services were able to communicate independently with one another, irrespective of the manufacturer, the operating system, the hierarchy and the topology.

The offered functionality of devices should be readable – but not for everyone. That requires security functions with authentication and encryption directly in the device. In case of failure of the data link the data should not be lost, but automatically buffered for a while.

Reality!

All of these wishes exist in reality. With regards to current-day situations where hard real-time requirements are not considered, this demanded interoperability can already now be achieved with the assistance of the OPC Unified Architecture (OPC UA).

The IEC62541 standard offers more than just the pure exchange of data: the description of the services, the modelling of the data of a device and their access rights are highly important in a networked world – only in this way can machines talk independently and directly to one another.

Oil & Gas pushing OPC UA

Today IT companies advertise that their protocols deliver the optimum for IoT solutions: IBM recommends the use of MQTT, while Microsoft prefers AMQP in its Azure cloud but also delivers several more IT connectors to appear flexible.

Of course, all these solutions push data being the new currency into their own cloud system – but their solutions do not provide interoperability. With the interoperability of the neutral international OPC UA standard the device manufacturers benefit by reducing system integration and also guarantee the build in secured data offerings.

High availability

Secured data and high availability was the key for Adwen/Areva to connect their wind turbines via OPC UA in 2008.

– OPC-UA was the favoured technology in Alpha Ventus, an offshore wind park test site in the North Sea, 45 kilometers from the German coast. The fully automated wind turbines controlled by a Windows Embedded CE based controller with IEC61131-3 logic and OPC-UA server are connected to a .NET based OPC-UA client application in an onshore control room. Compared to other open standards the inherent security and authentication mechanism of OPC-UA was the determining factor for this decision, reports Eike Grünhagen from Adwen GmbH.

– With a complex network infrastructure including different subnets and domains, connected via routers and protected by firewalls, configuration and administration becomes a difficult and time-consuming task. In the past, VPN tunnels for secure transmission and remote desktop connections were used. Now, with encrypted transmission, user authentication and audit functionality integrated into OPC-UA, access is possible down to individual data points, he continues.

Eike Grünhagen

Holger Junker

The Future Is OPC UA and TSN Real Time

Looking to the future, OPC UA will become the worldwide-accepted standard for IoT and Industrie 4.0. OPC UA is already the preferred communication standard selected by the Industrie 4.0 platform initiative in their RAMI4.0 (Reference Architecture Model Industrie 4.0).

Nevertheless OPC UA will be extended with new functionalities. Schneider Electric has initiated a new OPC collaboration group for mapping IEC61850 objects into OPC UA namespace.

Robotics vendor KUKA has identified some missing functionalities within OPC UA such as hard real-time capabilities. For this reason, KUKA became an OPC member to influence the direction and has initiated a working group within the OPC Foundation to evaluate and implement the usage of IEEE 802.1 Time Sensitive Network (TSN) technologies as an additional transport mechanism for OPC UA’s new publisher/subscriber protocol.

This will not replace other protocols such as all the existing Ethernet-based fieldbuses but OPC UA will offer Service Oriented Architecture (SOA). More important than that, however, there are the political benefits: OPC UA is not driven by a single company and as such is a common vendor-neutral standard.

Testimonial:

The only communication technology in the factory that I know of which has integrated security aspects and also offers potential for the challenges of Industry 4.0 is OPC UA. (17.11.2014)

Holger Junker

Federal Office of Security in IT (BSI), Head of Division C12 – Cyber Security in critical IT systems, applications and architectures

www.bsi.bund.de

 

Stefan Hoppe,

Vice President OPC-Foundation,

stefan.hoppe@opcfoundation.org