Applicable Systems
Series 0i
Series 16/18/21
Alpha
Beta
Symptoms
X axis has exceeded the negative direction travel limit.
Possible Causes
- Programmed movement exceeds axis travel limit
- Reference point position incorrect
- Limit switch malfunction
- Mechanical interference
Troubleshooting Steps
- Step 1: Switch to manual mode (JOG or HANDLE)
Machine responds to manual commands - Step 2: Move the axis away from the limit in the opposite direction
Axis moves away from the overtravel position - Step 3: Press RESET to clear the overtravel alarm
Alarm clears and axis is controllable - Step 4: Check the program coordinates and limit switch function
Coordinates are within travel range; limit switch functional
How to Reset
To reset overtravel alarm 511: 1) Switch to manual mode. 2) Move the affected axis away from the limit in the opposite direction. 3) Press RESET. 4) Verify the program coordinates are within the axis travel range. Caution: Forcing movement beyond limits can cause mechanical damage.
Frequently Asked Questions
- Q: What does 511 mean on Fanuc FANUC 0/0i/30i Series?
X axis has exceeded the negative direction travel limit.
- Q: How do I fix 511 on Fanuc?
Follow the troubleshooting steps: Switch to manual mode (JOG or HANDLE)
Source: FANUC CNC System Alarm Manual (doc.eleok.com)
Category: CNC