| Ethernet challenges the fieldbusses! |
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editorial | ||
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Opinions about Industrial Ethernet differ. Some protagonists shout: “We want it, it makes fieldbusses obsolete!”, using sometimes sound, sometimes questionable arguments (“consistency from sensor to CEO!“ – but what CEO really wants to see the sensor data from his production on the desktop?!). “My management has read about Industrial Ethernet in some magazine or other and asks me to replace the fieldbus in the next project – please provide me with arguments against this approach, I’m just happy that we have mastered the fieldbusses!” This type of call is also becoming more frequent. Depending on the background, fierce arguments for or against Ethernet are brought forward. Fieldbus cable manufacturers warn of the “Ethernet Monster”. Companies who have put all their cards on Ethernet naturally have a different opinion. And the user? Should he trust the Ethernet hype or the sceptics? As always, Beckhoff takes a differentiated and independent route. As a champion of open control technology, Beckhoff supports all open fieldbus standards with market significance. Beckhoff sits on the associated committees, has detailed knowledge of the advantages and weaknesses of the individual systems, can provide objective and sound advice, and doesn’t have to extol the virtues of an individual fieldbus system. The same applies to Industrial Ethernet. At Beckhoff, Ethernet has already been state of the art for networking of controllers for some time – after all, the pioneer of PC-based control technology has been using mainstream technologies and their advantages for some time. Ethernet interfaces are “native” for PCs, and Beckhoff uses them accordingly. But what about Ethernet on a sensor/actuator level? Here too, the proven Beckhoff strategy is used effectively: Getting involved early, building up knowhow in-house, pushing ahead the technology independently and with commitment, and of course supporting open standards, as soon as these are available. Accordingly, Beckhoff already expanded its I/O range with Ethernet couplers and IEC 61131-3 programmable Ethernet controllers three years ago. In addition to Beckhoff ADS, ModbusTCP was implemented, since this simple protocol is widely used. Numerous applications were solved successfully with these products – some of them were presented in previous issues of PC Control. At the same time, the technology was developed further, and real-time Ethernet was introduced at the end of last year: to date the only Ethernet implementation with real-time capability that only uses standard Ethernet cards and switches. Even simultaneous TCP/IP communication on the same network is possible! This was achieved through optimum integration of Ethernet drivers and Beckhoff real-time technology within the operating system. Once again the fact that all key technologies were developed in-house has paid off; particularly our own patented “real-time” under Windows was the basis for this success. Is Ethernet already the better fieldbus? As expected, Beckhoff’s response is carefully considered: Depending on the application, the fieldbusses still have advantages in terms of infrastructure costs, wiring effort and the wide availability of equipment and tools with real-time capability. Nevertheless, for certain applications the Beckhoff real-time Ethernet has advantages: fast machine controllers with large quantities of process data, physically large systems or small networks, for which the cost advantage of “Ethernet instead of fieldbus card” is significant. Real-time Ethernet is an important technology step – others will follow. The world of automation can again look forward to innovations from Beckhoff at the forthcoming Hanover Fair – particularly in terms of Ethernet! Martin Rostan
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Product Manager Ethernet and fieldbus systems