Siemens SINUMERIK MC Commissioning Manual page 115

4.6 SS2
Definition according to EN 61800-5-2:
The SS2 function brings the motor to a standstill with
subsequent safe monitoring of the standstill position.
When SS2-r is selected, the drive brakes the motor
along a braking ramp. The following variants are pos‐
sible:
● SS2-a with acceleration monitoring (SAM)
● SS2-r with braking ramp monitoring (SBR)
● Manually set delay time until SOS is activated.
This function corresponds to stop category 2 to
EN 60204‑1.
Example of how the function can be used
Example
A protective door must only be opened if a motor is in
the safe standstill state.
The safety function SS2 monitors the
load speed and initiates the SOS function
if the SS2 delay time has expired.
With SS2, braking is monitored on the
OFF3 ramp. A faulty acceleration is de‐
tected and the drive then shuts down with
STO.
If you are operating the motor with closed-loop torque control, the converter switches to the
closed-loop speed control mode when SS2 is selected.
Safety Integrated (with SINAMICS S120)
Commissioning Manual, 02/2020, A5E46305916B AB
Safety functions integrated in the drive
Select SS2
Solution
● Select SS2 in the converter via a terminal or
via PROFIsafe .
● After braking, the converter goes into the
SOS state. Only then may the protective
door be released.
4.6 SS2
SOS
115