Safe Torque Off (Sto) Safety Function; Function Description - Siemens SINAMICS G120D Operating Instructions Manual

8.8

Safe Torque Off (STO) safety function

These operating instructions describe the commissioning of the STO safety function when it
is controlled via a fail-safe digital input.
You will find a detailed description of all safety functions and control using PROFIsafe in the
Safety Integrated Function Manual, see Section Manuals for your converter (Page 292).
8.8.1

Function description

How does the STO safety function work?
Table 8- 25
1. The inverter recognizes the selection of STO via
2. The inverter prevents energy from being fed to
3. The inverter signals that "STO is active" via a
Figure 8-29
If the motor is still rotating when STO is selected, then it coasts down to standstill.
Converter with control units CU240D-2
Operating Instructions, 04/2014, FW V4.7, A5E34262100B AA
The principle of operation of STO
Safe Torque Off (STO)
a safety-relevant input or via the PROFIsafe safe
communication.
the motor. When STO is active, the motor does
not generate any torque.
safety-relevant output or via the PROFIsafe safe
communication.
Functionality of STO when motor is rotating and at a standstill
8.8 Safe Torque Off (STO) safety function
The inverter with active STO prevents machine
components from inadvertently starting.
Standard inverter functions linked with STO
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If you use a motor holding brake, the inverter
closes the brake.
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Setting functions
177