Failsafe automation systems are used in critical applications where a breakdown could lead to a hazard to people’s lives, or damage the environment or the plant. These so-called F/FH systems detect both errors in the process as well as any of their own internal errors. In the event of an error they automatically bring the plant into a secure state.
AS 410F Single Station with one CPU (failsafe)
AS 410FH Redundancy Station with two redundant CPUs (failsafe and fault-tolerant)
AS 410SIS with a single CPU or two redundant CPUs is the basic hardware for SIMATIC SIS compact stand-alone safety system
All AS 410F/FH systems are certified by TÜV (German technical inspection agency), and satisfy safety requirements up to SIL 3 in accordance with IEC 61508. In these multitasking-systems multiple programmes can run simultaneously in one CPU: Basic Process Control (BPCS) applications as well as failsafe applications. And these programs are non-reactive, which means errors in BPCS applications have no effect on failsafe applications and vice versa.