Abstract

International fieldbus standardization has always been a difficult endeavor. After a timely start in 1985 and a few enthusiastic years of development, the quest for the one and only comprehensive international fieldbus gradually became entangled in a web of company politics and marketing interests [1]. What followed was a protracted struggle inside CENELEC??

CENELEC = European Committee for Electrotechnical Standardization, see www.cenelec.org.

and IEC††

IEC = International Electrotechnical Commission, see www.iec.ch.

committees that finally ended up in the complete abandonment of the original idea. Instead of a single fieldbus, a collection of established systems was standardized. In Europe, CENELEC adopted a series of multivolume standards compiled from the specifications of proven fieldbus systems. On a worldwide scale, IEC defined a matrix of protocol modules, so-called types [2], together with guidelines as to how to combine the various modules into actually working fieldbus specifications [3]. With the adoption of the IEC 61158 standard [2] on the memorable date of December 31, 2000, the fieldbus war seemed to be settled just in time for the new millennium.