Siemens SINAMICS S120 Manual page 9

Safety function
Description of the automation task
In this example, STO and SLS are to be controlled via PROFIsafe with PROFINET.
PROFIsafe telegram 901 is also used to transfer limit values for the safely limited
speed (SLS) to the drive. The following conditions must be met in order that the
drive can operate with any speed: Protective door -S2 is closed, light barrier -S3 is
not interrupted, and therefore provides a HIGH signal at the output. However, if a
protective door low signal is transferred, then SLS becomes active – and the SLS
limit value is set by the F-CPU to 100% of the limit value saved in the drive. If the
light barrier -S3 supplies a low signal, then SLS also becomes active; however the
F-CPU reduces the limit value saved in the drive to 40%. If both sensors supply a
low signal, then the SLS limit value is reduced to 40%. In both cases, SLS level 1 is
active; however, only the signal state of light barrier -S3 defines as to whether the
limit value is reduced.
PROFIsafe SLS Override
Version 1.0, Entry ID: 81682475
When the light barrier is
interrupted, it is not
permissible that the drive
SF3
exceeds the velocity/speed
configured by the user. (low
limit value)
Description
SLS:
Monitoring of the drive
speed.
1 Task
Response
9