axismd.ai
FANUC Controller
Overtravel/Limit · Intermediate · 15-30 minutes
Fanuc Alarm 510 - OVER TRAVEL: +n (PRE-CHECK)
Alarm 510 OVER TRAVEL +n (PRE-CHECK) occurs when the CNC's stroke limit check calculates that the commanded end position of a move will exceed the software over-travel limit in the positive direction on the specified axis before motion begins. This is a pre-execution check using stored position limit parameters (1320-1327 series) and indicates either incorrect programming, improper work coordinate offset, or misconfigured stroke limit parameters.
510
Fanuc Alarm 510 - OVER TRAVEL: +n (PRE-CHECK)
Z+ Overtravel
Stroke check prior to movement detected that the end point in a block falls within the forbidden area in the positive direction along the N axis. Correct the program.
Root Cause Summary
Alarm 510 OVER TRAVEL +n (PRE-CHECK) occurs when the CNC's stroke limit check calculates that the commanded end position of a move will exceed the software over-travel limit in the positive direction on the specified axis before motion begins. This is a pre-execution check using stored position limit parameters (1320-1327 series) and indicates either incorrect programming, improper work coordinate offset, or misconfigured stroke limit parameters.
Safety
- Only jog in opposite direction of overtravel
- Be prepared to stop the axis immediately if it continues to move after the jog command is initiated.
- Power down the machine before inspecting or replacing any electrical components (limit switches, wiring).
- Ensure the work area is clear of obstructions before jogging the axis.
- Consult the machine's operation and maintenance manual for specific safety procedures.
Causes and Fixes
- 1
Identify the axis from alarm message (n = axis number: 1=X, 2=Y, 3=Z, 4=4th axis). Note the program block number and commanded position displayed on screen.
- 2
Navigate to SYSTEM > PARAM and check parameters 1320-1327 (stroke limit +). Parameter 1321=X+, 1322=Y+, 1323=Z+. Verify these values match machine physical limits and are set in machine coordinate system units.
- 3
Press OFFSET button and check active work offset (G54-G59). Add work offset value to programmed coordinate to calculate machine position. If sum exceeds parameter 132x value, either modify program coordinate or adjust work offset.
Do not arbitrarily increase stroke limit parameters without verifying physical machine travel limits to prevent collision
- 4
If program is correct, verify parameter 1320 bit 0 (OT1) = 1 to enable software over-travel check. If limits need adjustment, modify parameters 1321-1327 after confirming actual machine travel with handwheel in JOG mode.
Call a technician if:
- ·Position feedback system errors
- ·Parameter corruption requiring factory defaults
- ·Mechanical limit switch problems
Prevention
- Regularly verify work offset accuracy
- Include software limit checks in program validation
- Maintain proper tool length offset values
- Use program simulation before first run
Common Mistakes
- Confusing machine coordinates with work coordinates
- Ignoring tool length compensation in limit calculations
- Setting software limits too close to physical limits
- Not accounting for workpiece thickness in Z+ calculations
Seeing Multiple Alarms?
Seeing another alarm with this one? Enter the code.
Get machine-aware diagnosis
AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.
Start freeWas this guide helpful?
Always verify with your machine manual or a certified technician before performing service procedures.