Applicable Systems
TwinCAT NC
Symptoms
NC axis homing error. The reference point homing sequence has failed.
Possible Causes
- Reference point switch not triggered during homing travel
- Reference point switch malfunction or misalignment
- Homing velocity too high: switch debounce missed
- Encoder zero mark not found during homing
Troubleshooting Steps
- Step 1: Check the equipment status and fault indicators to confirm the active fault code
Fault indicator or HMI displays code 0x4112 as active - Step 2: Verify all electrical connections, wiring harnesses, and connector seating
All connections secure, no corrosion, loose pins, or damaged wires - Step 3: Check encoder cable and connector at both motor and drive/controller ends
Cable intact, connector fully seated, no bent or corroded pins - Step 4: Verify encoder signal integrity with an oscilloscope if available
Signal waveform normal with clean edges, no dropouts or noise - Step 5: Check for mechanical interference, coupling slippage, or excessive load on the axis
No mechanical interference, coupling secure, load within rated capacity - Step 6: Verify the axis reference point and home position are valid
Axis has valid reference point, position data is consistent - Step 7: Replace encoder if signal is consistently absent or corrupted after cable checks
New encoder provides stable, clean signal
How to Reset
To reset: 1) Identify and fix the root cause described in the fault symptoms. 2) Press RESET on the HMI or controller, or power-cycle the equipment. 3) If the fault recurs, contact manufacturer service. Caution: Document the fault code and context before resetting.
Frequently Asked Questions
- Q: What does fault code 0x4112 mean on the Beckhoff TwinCAT NC?
Fault 0x4112 indicates a position or encoder-related fault. The control system has detected an issue with axis positioning, speed feedback, or encoder signal. Check the encoder cable and motor feedback system.
- Q: Can I continue operating the equipment with fault 0x4112 active?
No. The equipment has detected a fault condition and has taken protective action (typically stopping or derating). Continuing to operate without fixing the root cause may cause further damage. Always investigate and fix the fault before resuming operation.
Source: Beckhoff TwinCAT NC Error Codes (TwinCAT2_NC_Error_Codes_EN.pdf), Beckhoff Automation
Category: CNC