Siemens SIMATIC ET 200SP Manual page 105

Proof test interval
Time interval after which a component must be put into error-free state. The component is
replaced or proof is furnished that it is entirely free of errors.
Safe state
The basis of the safety concept in fail-safe systems is that a safe state exists for all process
variables.
Safety class
Safety Integrated Level (SIL) acc. to IEC 61508. The higher the safety integrity level, the
stronger the measures for avoiding systematic failures as well as for overcoming intermittent
failures and hardware failures.
Fail-safe modules used in safety mode can achieve up to safety class SIL 3.
Fail-safe Module F‑CM AS‑i Safety ST (3RK7136‑6SC00‑0BC1)
Manual, 03/2017, A5E03957059020A/RS-AB/002
Glossary
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