Siemens SIMATIC ET 200SP Product Information page 36

Glossary
Safety class
Safety level (Safety Integrity Level) SIL according to IEC 61508:2010. The higher the Safety
Integrity Level, the more rigid the measures for prevention of systematic faults and for
management of systematic faults and hardware failures.
The fail-safe modules support operation in safety mode up to safety class SIL3.
Safety function
A mechanism integrated in the → F-CPU and → F-I/O that enables their use in → the fail-safe
system SIMATIC Safety.
According to IEC 61508:2010 A safety function is implemented by a safety system in order to
maintain or force a system safe state in the event of a specific fault.
Safety message frame
In safety mode, data are transferred between the → F-CPU and → F-I/O in a safety message
frame.
Safety mode
Operating mode of → F-I/O that enables → safety-related communication via → safety
message frames.
→ ET 200SP fail-safe modules can only used in safety mode.
Safety program
Safety-related user program
Safety-related communication
Communication used to exchange fail-safe data.
Sensor evaluation
There are two types of sensor evaluation:
→ 1oo1 evaluation – sensor signal is read once
→ 1oo2 evaluation – sensor signal is read in twice by the same F-module and compared
internally
Sensors
Sensors are used for accurate detection of digital and analog signals as well as routes,
positions, velocities, rotational speeds, masses, etc.
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ET 200SP distributed I/O system
Product Information, 07/2013, A5E32288220-AA