Siemens SINAMICS G120 Function Manual page 56

Description
2.7 Safe Speed Monitor, SSM
The feedback signal "SSM active" remains active when the pulses are inhibited (p9309.0 = 0)
In order to ensure that the motor is at a standstill after switching off, you must set parameter
p9509.0 = 0 . In this case, after the motor is switched off, the inverter interrupts the SSM
function, but by specifying STO , prevents the motor from accelerating.
Proceed as follows to switch the motor off and on again when SSM is active:
● Select STO after the motor has been switched off.
● Deselect STO again before you switch on the motor.
● Switch on the motor within 5 seconds (ON command).
If you do not switch on the motor within 5 seconds, then the inverter again goes into the STO
state and no longer responds to the ON command. To switch the motor on again, proceed as
follows:
● Select STO .
● Deselect STO again.
● Switch on the motor within 5 seconds (ON command).
54
Figure 2-29 Switching the motor off and on when SSM is active
Safety Integrated Function Manual, SINAMICS G120 and G120C
Function Manual, 01/2011, FW 4.4, A5E03052391B AB