Siemens SINAMICS DCM Operating Instructions Manual page 669

13.4 Fundamental safety technology principles
13.4.1 Standard stop functions
13.4.1.1 Emergency Off and Emergency Stop
"Emergency Off" and "Emergency Stop" are commands that minimize different risks in the
machine or plant.
The STO function is suitable for achieving an Emergency Stop but not an Emergency Off.
You can review the details about the definitions in EN 60204-1.
Risk:
Measure to minimize
risk:
Command:
Solution:
SINAMICS DCM Control Module
Operating Instructions, 12/2018, A5E34888669A
Risk of electric shock:
Safe switch off
Switching off the electric power
supply for the installation, either
completely or partially.
Emergency Off
Switch off the power supply:
13.4 Fundamental safety technology principles
Risk of unexpected motion:
Safely stop and safely prevent
restarting
Stopping or preventing the dangerous
movement
Emergency Stop
Select STO:
It is permissible that you switch off
the inverter power supply as well.
However, switching off the voltage is
not required as a risk-reduction
measure:
Functional safety
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