ABSTRACT
Throughout the history of automation, many inventions and developments have influenced the face of manufacturing and information processing. But few novelties have had such a radical effect as the introduction of fieldbus systems, and no single achievement was so heavily disputed as these industrial networks. And yet, they have made automation what it is today. But even after some 20 years of fieldbus development, there exists no clear-cut definition for the term. The “definition” given in the IEC 61158 fieldbus standard is more a programmatic declaration, or a least common multiple compromise, than a concise formulation [1]: “A fieldbus is a digital, serial, multidrop, data bus for communication with industrial control and instrumentation devices such as — but not limited to — transducers, actuators and local controllers.” It comprises some important characteristics, but is far from being complete. On the other hand, it is a bit too restrictive.
