Safe Operating Stop (Sos) - Siemens Sinamics S120 Function Manual

Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
4.2.7

Safe Operating Stop (SOS)

This function serves for fail-safe monitoring of the standstill position of a drive.
Danger to life: Drive can be forced out of the S OS position by mechanical forces
Mechanical forces greater than the maximum drive torque may force a drive currently
operated in the position control mode out of the Safe Operating Stop (SOS) and trigger stop
function category 1 according to EN 60204-1 (fault response function STOP B).
• If there is a hazard due to unwanted movement in your application, take measures to
Not e
S OS only with encoder
In particular, the motor is energized while the SOS function is performing position control.
• Ensure that the motor cannot be touched while it is in the SOS state.
Drive stopping is monitored using an SOS tolerance window (p9530).
Not e
S iz e of the t olerance window
The size of the tolerance window should be slightly above the standard standstill monitoring
limit, otherwise the standard monitoring functions will no longer be effective.
Parameter r9731 displays the safe position accuracy (load side) that can be achieved as a
maximum, based on the acquisition of the actual value for the safe motion monitoring
functions.
STOP B is the stop response after the standstill tolerance window has been violated.
The SOS function comes into effect in the following cases:
● After SOS is selected and the delay time in p9551 has elapsed
The drive must be braked to standstill within this delay time (e.g. by the controller).
● As a consequence of SS2
● As a consequence of STOP C (corresponds to selection of SS2)
● As a consequence of STOP D (corresponds to selection of SOS)
● As a consequence of STOP E (corresponds to selecting SOS with additional activation of
the standard "Extended stop and retract (ESR)" function)
92
WA RNING
counter it, for example, by using a brake with safe monitoring. For further information,
see Chapter "Safe Brake Control (SBC) (Page 71)."
Function Manual, (FHS), 07/2016, 6SL3097-4AR00-0BP6
Safety Integrated