Siemens SIMATIC ET 200SP System Manual page 91

Wiring
6.2 Additional rules and regulations for the operation of the ET 200SP with fail-safe modules
Additional requirements for sensors for fail-safe motor starters
Only single-channel sensors that fulfill the required safety category themselves may be
connected to the fail-safe motor starter's F-DI. Fail-safe laying must be observed in
accordance with the required safety category.
Safety-related shutdown using the F-DI
Depending on the I/O used, the shutdown takes place via one or two output channels
(terminals):
• PM-switching: The shutdown takes place via two output channels.
• PP-switching: The shutdown takes place via one output channel.
Shutdown via only one output channel (PP-switching) achieves SIL 3 according to
EN 62061, PL e / Cat. 4 according to EN ISO 13849-1, if it is ensured that the cabling is
installed in a cross-circuit-proof/P-short-circuit-proof manner.
Duration requirements for sensor signals
Observe the following requirements for sensor signals:
• To ensure the correct detection of the sensor signals via fail-safe modules with inputs,
• For pulses to be detected with certainty, the time between two signal changes (pulse
Reliable detection by F-modules with inputs
The minimum duration of sensor signals for F-modules with inputs depends on the
configured input delay, the parameters of the short circuit test of the sensor supplies, and the
configured discrepancy behavior for 1oo2 evaluation. The signal must be greater than the
maximum response time of the configured application. Information on calculating the
maximum response time can be found in the section "Response times" of the relevant F-
module.
The maximum permitted switching frequency of the sensor signals results from the minimum
duration.
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WARNING
WARNING
you need to make sure that the sensor signals are output for a minimum duration.
duration) must be greater than the PROFIsafe monitoring time.
Distributed I/O system
System Manual, 09/2019, A5E03576849-AJ