Safe Operating Stop (Sos) - Siemens SINUMERIK 828D Function Manual

Description of the Safety Integrated Extended Functions

3.5 Safe Operating Stop (SOS)

3.5 Safe Operating Stop (SOS)
How does SOS function?
This function serves for fail-safe monitoring of the standstill position of a drive. The protected
machine areas can be entered without having to shut down the machine as long as SOS is
active.
Drive stopping is monitored using an SOS tolerance window. When this function is activated,
the current actual position is saved as a comparative position, until SOS is deselected again.
Any delay time is cleared after SOS is deselected and the drive can be immediately moved.
STOP B is the stop response after the standstill tolerance window has been violated.
Note
Contrary to SS1 and SS2, SOS does not automatically brake the drive:
The control still enters the setpoint. This means that in the user program of the control
system, the system must respond to the "SOS selected" bit so that the control system brings
the drive to a standstill within the delay time.
Figure 3-2
24
Standstill tolerance
Function Manual, 07/2012, 6FC5397-3EP40-3BA0
Safety Integrated