F31110Fault · Encoder 1Usually repairable
SINAMICS S120 F31110: Encoder 1 Serial Communications Error
Also shown as: Can be set as N, A
What F31110 means
Serial communication between the drive and the motor's absolute encoder (for example EnDat or SSI) failed.
Symptoms
Fault at power-on or random trips while the axis moves.
Is it repairable?
Yes: encoder replacement and alignment are standard repairs.
Common causes
- Damaged encoder cable or connector
- Failed encoder
- Faulty Sensor Module
- Electrical noise from poor shielding
Safe checks
- 1Inspect the encoder cable and connector for damage or coolant
- 2Check shield grounding
- 3Swap a known-good cable if available
Drives hold dangerous voltage after power-off. Checks should only be done by qualified personnel, with power isolated and the DC link discharged.
Reviewed by AutomIQ repair technicians. Code and name from the SINAMICS S120/S150 List Manual.
Related SINAMICS S120 faults
- F07011Motor overtemperature
- F07900Motor blocked/speed controller at its limit
- F30001Overcurrent
- F30002DC link voltage overvoltage
- F30003DC link voltage undervoltage
- F30004Overtemperature heat sink AC inverter