Safety Integrated function
8.2 General information about SINAMICS Safety Integrated
SINAMICS V90, SIMOTICS S-1FL6
306 Operating Instructions, 04/2019, A5E36037884-007
General information about SINAMICS Safety Integrated
Safety Integrated function - STO
The Safe Torque Off (STO) is a safety function that prevents the drive from restarting
unexpectedly, in accordance with EN 60204-1:2006 Section 5.4.
The STO function is in conformance with the IEC 61508, SIL2 standard, in the operating
mode with a high demand, Category 3 and Performance Level d (PL d) acc. to ISO 13849-
1:2015, as well as IEC 61800-5-2.
Controlling the STO Function
The STO function can be controlled via terminals. For the details about STO wiring, refer to
the chapter "24 V power supply/STO (Page 162)".
STO functional safety data
The STO functional safety data of SINAMICS V90 is as follows:
IEC 61508, IEC 62061, ISO 13849-1
Safety Integrity Level (SIL) 2
Hardware Fault Tolerance (HFT)
Probability of Failure per Hour (PFH) 5 × 10
-8
per hour
The safety function of the SINAMICS V90 drive system meets the following requirements:
● Category 3 according to ISO 13849-1:2015
● Performance Level (PL) d to ISO 13849-1:2015
● Safety integrity level 2 (SIL 2) to IEC 61508
In addition, the safety function of SINAMICS V90 has been certified by independent institutes.
An up-to-date list of certified components is available on request from your local Siemens
office.