Austin, TX, February 14, 2004: The Fieldbus Foundation (FF) today announced that TUV Anlagentechnik GmbH, Automation, Software and Information Technology, a global, independent, and accredited testing agency, has approved its Safety Instrumented Systems (FF-SIS) system concept. The FF-SIS project was initiated by end users and approved by the foundation's board of directors in October 2002. The TÃV approval clears the way for validation of the FF-SIS technical specifications during 2004.
Foundation fieldbus, with its industry-proven distributed function blocks and open communications protocol, is an ideal platform for advancing standards-based safety-instrumented systems technology. The foundation, in concert with leading device manufacturers and end users, is developing specifications and guidelines that comply with the International Electrotechnical Commission (IEC) 61508 standard (functional safety of electrical / electronic / programmable electronic safety-related systems), and IEC 61511 (functional safety: safety instrumented systems for the process industry sector). IEC 61511 addresses the application of safety-instrumented systems.
According to David A. Glanzer, Fieldbus Foundation director of technology development, the FF-SIS development team did an outstanding job of identifying system requirements and completing development of draft technical specifications on schedule.
"TUV has independently verified that the system concept defined in the foundation's specifications meets the project requirements," said Glanzer. "The specifications will enable instrumentation suppliers to build a wide range of devices that comply with IEC 61508. Third-party certifiers, such as TUV, 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."
Glanzer continued, "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 Fieldbus Foundation's Technical Steering Committee, senior technologists and end users from foundation member companies collaborated on the FF-SIS project plan and developed a system architecture and draft specifications to meet the TUV 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, TUV, 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, 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.
