Siemens SINAMICS S120 Commissioning Manual page 259

Differences between Safe Speed Monitor with and without encoder
● For Safe Speed Monitor without encoder, after pulse suppression the drive is unable to
determine the current velocity. Two responses can be selected for this operating state
with the "SSM active feedback for pulse inhibit" drop-down list:
– "Becomes active": The status signal (SSM feedback signal) shows "0" (factory
– "Becomes inactive": The status signal (SSM feedback signal) is frozen. "Safe Torque
Figure 4-108 SSM without encoder
Commissioning with Startdrive
Commissioning Manual, 11/2017, 6SL3097-4AA10-0BP1
setting).
Off" (STO) is selected internally.
Commissioning
4.10 Safety Integrated commissioning
259