The AC500-S is realized as 1oo2 system (both safety CPU and safety I/O modules) and can be used to handle safety functions with SIL 3 (IEC 61508), max. SIL 3 (IEC 62061) and PL e (ISO 13849-1) requirements in high-demand systems of safety machinery applications and low-demand systems of safety process applications. 1oo2 system includes two microprocessors. Each of them executes the safety logic in its own memory area and both compare the results of the execution. If a mismatch in the execution or an error is detected, the system goes to a safe state, which is described for each of the safety modules separately.