Applicable Systems
S7-1200
S7-1500
S7-300
S7-400
LOGO!
SINAMICS
Symptoms
Safe Torque Off (STO) safety function is active.
Possible Causes
- STO input activated
- Safety command received
- Emergency stop circuit triggered
Troubleshooting Steps
- Step 1: Check STO input signal
STO input inactive when safe - Step 2: Verify emergency stop circuit
Circuit normal - Step 3: Clear STO command
Command cleared
How to Reset
Reset by clearing STO command and acknowledging fault.
Source: Siemens SINAMICS G120 List Manual
Category: PLC & VFD