Siemens SINAMICS G120 - Switching off the Motor When SSM Is Active

6.7.3 Switching off the motor when SSM is active
The drive response depends on the following conditions:
● Motor speed at the instant when it is switched off
● Off command: OFF1, OFF2 or OFF3
● Setting the SSM function:
– Feedback signal "SSM active" for pulse inhibit remains active:
When the motor is switched off, the inverter prevents the motor from accelerating by
issuing an STO. When the motor is switched off, "Status SSM" = 1.
– Feedback signal "SSM active" for pulse inhibit becomes inactive:
When the motor is switched off, the inverter sets "Status SSM" = 0.
When switching off, the speed is less than the SSM limit value
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Figure 6-36 OFF1 command when the SSM safety function is active
If you switch off the motor with the SSM function active using the OFF1 or OFF3 command,
e.g. when reaching limit switches, the following happens:
1. The inverter brakes the motor down to standstill and then switches it off.
2. Also while braking, the inverter monitors the motor speed.
If the "SSM active" feedback signal should remain active when the pulses are inhibited, then
the inverter safely switches off the motor torque using the safety function STO.
Operation
6.7 Safe Speed Monitor (SSM)
Safety Integrated - SINAMICS G110M, G120, G120C, G120D and SIMATIC ET 200pro FC-2
274 Function Manual, 01/2017, FW V4.7 SP6, A5E34261271B AD