Heinrich Munz, Lead Architect Industry 4.0 at Kuka, adds to Georg Kopetz's comments in his role as moderator that TSN only defines the real-time capability on layer 2 of the ISO/OSI 7 layer model. In order to achieve manufacturer-independent interoperability of automation components in the factory of the future, he is convinced that it is essential to establish OPC UA with semantic service descriptions on top of TCP(UDP)/IP and TSN.

The combination of TSN plus OPC UA

Stefan Hoppe, Vice President of the OPC Foundation, explains the idea of TSN plus OPC UA in detail: "Simply tunneling the colourful zoo of protocols via TSN doesn't really help," he is convinced. Purely transporting bits and bytes via OPC UA and TSN is not the key either - that is already the proven benefit of established fieldbuses. Rather, the emerging trends in automation demand a service-oriented architecture - SoA for short - almost everywhere! Hoppe underlines his thesis using automation examples that show the interaction of a wide variety of automation components via OPC UA and TSN.

Stefan Schönegger from B&R is also certain that "the establishment of TSN in conjunction with OPC UA will leave no stone unturned in industrial automation". In his opinion, control technology in particular will change significantly. He also sees the automation pyramid changing into a hierarchy-free Industrial Internet of Things. Schönegger draws this conviction from the experience that B&R is currently gaining with the technologies. On the one hand, through its involvement in various working groups - such as the OPC UA working group for PubSub and TSN or corresponding working groups at OMAC/CPG and VDMA/Euromap. On the other hand, the experience that the company has gained through its participation in the TSN testbed of the Industrial Internet Consortium (IIC) has led to B&R having concrete TSN plans: The technology roll-out of OPC UA and TSN on all controllers is to take place next year; the X20 IO system will also undergo a corresponding product roll-out in 2017.

First TSN devices

Stephan Kehrer, Technologies Manager at Hirschmann/Belden, reports on initial experiences with realized TSN products. His company presented the first TSN-based switches at the Hannover Messe.

His conclusion: "TSN is a reality today." Thanks to the publication of central standards, TSN can already be used, even if parts of the final standard are not yet fixed. He describes in detail the implementation considerations that Hirschmann had to take into account during device development: when does it make sense to use an FPGA to implement TSN and when is it better to rely on standard silicon? Which of the eleven sub-standards has what proportion of hardware or software? What additional criteria need to be taken into account during device development? - And how will customers react to TSN-capable devices? "Customers are sensitized," reports Kehrer, "we have had a strong demand from users since Hanover, which we had not expected!"

What happens to the fieldbuses?

A question that comes up again and again during the day: To what extent will TSN displace the established fieldbuses? A slide presented by Heinrich Munz at the beginning of the event does not exactly reassure the fieldbus clientele: It shows that Intel expects the cycle times achievable with TSN to be less than 10 µs. Even real-time specialists such as Profinet IRT and Sercos (both up to 31.25 µs) don't look very good with values like that. And yet: Christian Schlegel from HMS and Peter Wenzel from the Profibus user organization do not believe that fieldbus systems are at the end of the road. "The real value of the established fieldbus and industrial Ethernet systems lies in the established ecosystems, interoperability and applicability," argues Schlegel. Peter Wenzel adds: "We can survive if we do the right thing - and we have been doing the right thing for 27 years!" He points out that the PNO is cooperating with the OPC Foundation, particularly with regard to the administration shell, and that it is quite conceivable that the PNO will provide hardware support in the future, offering TSN in addition to IRT and RT.