Siemens SINAMICS G120 Operating Instructions Manual page 246

Functions
9.10 Fail-safe function Safe Torque Off (STO)
Table 9- 61 Function "Safe Torque Off" (STO)
No.
1. Initial state
The converter is "ready" (p0010 = 0).

The converter signals neither faults nor alarms for the safety functions (r0945[0...7], r2122[0...7]).

STO is not active (r9773.1 = 0).

2. Switch on the motor
Enter a speed setpoint ≠ 0, and switch on the motor (ON command).

Ensure that the correct motor is running.

3. STO select
Select STO while the motor is running

Note: Test each configured control, e.g. via digital inputs and via PROFIsafe.
Check the following:

For control via PROFIsafe
The converter signals the following:

"STO Selection via PROFIsafe"
(r9772.20 = 1)
If a mechanical brake is not available, the motor coasts down.

A mechanical brake brakes the motor and holds it to ensure that it remains at a standstill.
The converter signals neither faults nor alarms for the safety functions (r0945[0...7],

r2122[0...7]).
The converter signals the following:

"STO is selected" (r9773.0 = 1).
"STO is active" (r9773.1 = 1).
4. STO deselect
Deselect STO .

Check the following:

The converter signals neither faults nor alarms for the safety functions (r0945[0...7],

r2122[0...7]).
The converter signals the following:

"STO is not selected " (r9773.0 = 0).
"STO is not active" (r9773.1 = 0).
The converter is in the "switching on inhibited" state (r0046.0 = 1).

5. Switch on the motor
Switch the motor off (OFF1 command) and then on again (ON command).

Ensure that the correct motor is running.

244
Description
For control via terminal
The converter signals the following:

"STO Selection via terminal " (r9772.17 = 1)
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB
SINAMICS G120C frequency converter
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