Siemens SIRIUS 3SK1

9.4 Response times
Veri󹪝cation of response times in the case of safety circuits
When safety equipment is commissioned, steps must be taken to verify that a safety-related
output will switch o󹪜 within a maximum permissible response time if the input signal changes
at the relevant input.
To provide this veri󹪝cation, you must determine the total response time of the application you
have con󹪝gured.
Note
Note that the calculation of the response time a󹪜ects the level of safety and governs the overall
design of the system.
You can 󹪝nd the response data of the safety relays in the technical speci󹪝cations of the respective
devices in the chapter "Technical data (Page 191)".
You can 󹪝nd the response data of the 3RM1 Failsafe motor starters in the technical
speci󹪝cations in the "SIRIUS 3RM1 motor starters (http://support.automation.siemens.com/WW/
view/EN/ 66295730)" manual.
Calculation of the response times
To calculate the response times of the overall system con󹪝guration, you must add up the
individual response times of all input expansions a󹪜ected by deactivation and also the response
time of the basic unit.
If output expansions are used, the response times of the relevant output module are also added
to the total time from the sensor to the actuator.
Examples
Example 1
3SK1121-.AB40 + 3SK1211.BB40
40 ms 50 msResponse time:
Example 2
3 x 3SK1220 + 3SK1122-.AB40 + 3SK1211-.BB40 + 3RM1 Failsafe motor starter
Con󹪝guration / operation
9.4 Response times
SIRIUS 3SK1 Safety Relays and 3RQ1 Positively-Driven Coupling Relays
180 Equipment Manual, 05/2021, A5E02526190021A/RS-AE/005