Siemens SIMATIC ET 200SP System Manual page 313

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 mode
Operating mode of → F-I/O that enables → safety-related communication via → safety 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.
Self-assembling voltage buses
Three internal, self-assembling buses (P1, P2 and AUX) that supply the I/O modules with
power.
SELV
Safety Extra Low Voltage
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 the accurate detection of routes, positions, velocities, rotational
speeds, masses, etc. in the form of digital and analog signals.
Server module
The server module completes the configuration of the ET 200SP.
Distributed I/O system
System Manual, 09/2019, A5E03576849-AJ
Glossary
313