Open gateway will link Profibus to Ethernet

Endress + Hauser has renewed its attack on Fisher-Rosemount, alleging that it is not licencing technologies that are vital for implementing Foundation Fieldbus (FF) systems. Diether Schaudel, E+H`s director for technology, has accused Fisher-Rosemount of using patents as "a strategic weapon" and warned suppliers and users of FF products that they could face "uncertain bills" if they adopt FF technology.

Earlier this year, E+H said that parts of the international and European field bus standards IEC 61158 and EN 50170 could not be applied without infringing certain Fisher-Rosemount patents. It suggested that an attempt was being made to use the cover of an international standard to develop and protect a monopoly, and that it was only possible to apply the standards if you infringed on the four patents or had a licence.

Speaking at a recent ISA meeting in the US, Schaudel revealed that before issuing the earlier statement, E+H had been negotiating for many months with the Fieldbus Foundation and Fisher-Rosemount to resolve the issue - without success.

The Foundation had known about the issue for more than a year "and had not done anything to solve it," Schaudel said. And negotiations with Fisher-Rosemount, started in June 1999, had broken down.

Although the Foundation and Fisher-Rosemount had spoken of offering "royalty-free" licences for the technology, Schaudel said that these were only valid for five years. "Nobody knows what will happen after that," he added. "This means, whoever enter such a licence agreement, risks an uncertain bill in the future."

Schaudel rejected accusations that the E+H campaign was intended to promote Profibus or that E+H was working on behalf of Siemens. "We are actively for Fieldbus Foundation, not against it," he declared, adding that E+H probably has the widest range of FF instruments after Fisher-Rosemount.