Reinach, Germany— Though it's more than amazing that no one noticed before, patent engineers at Endress+Hauser Group reported Mar. 3 that essential parts of the newly approved IEC 61158 fieldbus standard are protected by patents or patent claims of certain companies.

The firm says a routine check turned up this revelation after publication of IEC 61158 and just before an intended expansion of EN 50170, the Euronorm standard for "general purpose field communication systems." Consequently, E+H's management has requested the respective secretariats of the International Electrotechnical Commission (IEC, Geneva, Switzerland) and CENELEC to withdraw the extension and publication of the respective standards until IEC 61158's legal position has been clarified.

Dick Caro, former convenor of IEC SC65c working group 6, which compiled much of IEC 61158 before it was merged with seven other protocols, says E+H is apparently concerned about approximately 17 patents held by Fisher-Rosemount (F-R, Austin, Tex.) and Fisher Controls (Marshalltown, Ia.) that were issued between 1997-99. These patents deal with the companies' PlantWeb architecture and DeltaV automation system, as well as some control valves and field instrumentation.

E+H is reportedly worried that the patents are too generally stated; go beyond PlantWeb and DeltaV technical principles; and are linked closely enough to FOUNDATION fieldbus technology that manufacturers trying to develop IEC 61158-based products might be challenged as trespassing on the patents. Fisher-Rosemount officials were expected to issue a statement responding to E+H's questions, but it wasn't available at press time.

"We recognized, in these standards, that this part of the Fieldbus Foundation includes a labyrinth of patents and patent applications of individual manufacturers. Whoever applies this section of international standards, be it a manufacturer or user, runs the risk of infringing a patent and being subjected to claims for damages," says Diether Schaudel, E+H's chief technology officer. "Since all this is so impenetrable, general statements concerning the relevance or otherwise of the patents, are not sufficient by any means. We can't be certain at the moment that other parts of the standard are not covered by restrictive patents until a declaration has been made by the patent owners that they are willing to grant a license to users."

In a letter to IEC and CENELEC, E+H asked that any relevant proprietary rights established through patents be individually, completely, and conclusively listed in the standards, and that the owners of the patents declare their unlimited willingness to grant licenses in accordance with the IEC and CENELEC rules. Mr. Caro says IEC's standard procedure for dealing with patent issues is that if there are any claims against part of a standard, then IEC assumes the patent holder will be willing to grant licenses to developers based on fair (meaning non-restrictive) and reasonable (meaning not prohibitively high-priced) compensation.

E+H's request for clarification under IEC's fair and reasonable clause isn't expected to be able to slow or reverse IEC 61158's publication as the international fieldbus standard, unless the applicable patent holders refuse to grant licenses or prices them above a reasonable level. Mr. Caro says patent holders with defensive motivations usually grant licenses under this clause, while others may seek to prohibitively protect their positions. If an offensive stance is taken relative to IEC 61158, then E+H could challenge the patents in court, ask the IEC to decide whether its fair and reasonable clause was violated, or even seek to have part of the standard removed. Besides simply granting licenses, he adds other possible settlement methods could include cross-licensing agreements formed by the parties involved.

"Today, it's obvious that one cannot speak of an 'open standard,' " adds Mr. Schaudel. "Anyone who has been involved in patent proceedings, particularly in the U.S., knows of the power a patent holder has at his disposal and of the financial risks that can follow a possible infringement. We regret very much that the endeavors of creating a uniform fieldbus standard, which have been going on for years, are now faltering. During recent years, we have made significant investments in the development of fieldbus technology and its international implementation, and we probably have the most comprehensive range of field instruments geared to this technology worldwide. However, in the interest of our customers around the globe, we cannot permit individual companies to obtain monopolies protected by patents with a Trojan horse of an international standard."