Selecting devices for use in Safety Systems

摘要

IEC61508 is recognised as 'best practice' in the use of electrical, electronic and programmable systems in functional safety. The end user or the system integrator is thus encouraged to comply with this standard or to a derivative standard, such as IEC 61511 for the process industries. This task is simplified when he can buy safety system devices that have been designed, manufactured and certified to IEC 61508. A device that genuinely complies with IEC 61508 and, even better, is so certified, carries the assurance that it should perform reliably in a safety system. Also, it comes with the reliability data that is needed to integrate it as part of the safety system. The essential parts of a safety function are a sensor, a logic solver, and an actuator.