TÜV approves Fieldbus Foundation's FF-SIS concept
Austin, TX—The Fieldbus Foundation (FF) has announced that TÜV Anlagentechnik GmbH recently approved its Safety Instrumented Systems (FF-SIS) system concept.
Austin, TX— The Fieldbus Foundation (FF) has announced that TÜV Anlagentechnik GmbH recently approved its Safety Instrumented Systems (FF-SIS) system concept. The FF-SIS project was initiated by end-users and approved by FF's board of directors in October 2002. TÜV's approval clears the way for validation of FF-SIS' technical specifications during 2004. TÜV is a global, independent, accredited testing agency focusing on automation, software, and information technologies.
FF reports that FOUNDATION fieldbus, with its distributed function blocks and open communications protocol, is an ideal platform for advancing standards-based safety instrumented systems technology. The foundation, in conjunction with leading device manufacturers and end-users, is developing specifications and guidelines that comply with the International Electrotechnical Commission (IEC) 61508 standard, which covers functional safety of electrical/electronic/programmable electronic safety-related systems, as well as IEC 61511, which covers functional safety of instrumented systems for the process industries.
David Glanzer, FF's technology development director, reports that the FF-SIS development team did an outstanding job of identifying system requirements and completing development of draft technical specifications on schedule. 'TÜV has independently verified that the system concept defined in the foundation¹s specifications meets the project requirements,' says Glanzer. 'The specifications will enable instrumentation suppliers to build a wide range of devices that comply with IEC 61508. Third-party certifiers, such as TÜV, will certify the Safety Integrity Level (SIL) capability of the instruments based on this standard. In addition, end-users will evaluate the requirements for their safety instrumented systems according to the IEC 61511 standard.
'End users want an open solution such as FF-SIS, so they can choose certified instruments from multiple suppliers, instead of being restricted to devices specifically designed for a proprietary safety instrumented system. Suppliers want an open solution because it allows them to sell their products to more users, instead of only to users operating a proprietary system.'
Under the direction of the foundation's Technical Steering Committee, senior technologists and end-users from FF's member companies collaborated on the FF-SIS project plan and developed a system architecture and draft specifications to meet the TÜV requirements.
Companies on the FF-SIS development team include ABB, DuPont, Emerson Process Management, ExxonMobil, HIMA, Honeywell, Invensys/Triconex, Metso Automation, Rockwell Automation, Rotork Control Systems, Saudi Aramco, Shell Global Solutions, Smar, Softing, TÜV and Yokogawa.
To meet the requirements of the IEC 61508 standard, FF-SIS specifies a special protocol layer between the standard fieldbus communications and the function block application process. The special layer adds error checking to ensure that, if a device malfunctions and sends out a bad message, then the bad message is detected, and proper action is taken. The FF-SIS project also specifies a 'Write Lock,' which requires a special 'key' to enable changes. Only authorized personnel who have access to the key can make changes.
Control Engineering Daily News Desk
Jim Montague, news editor