OT0504

Identify Active Offset

Navigate to the OFFSET SETTING screen on the control panel and identify the active workpiece coordinate system (e.g., G54). Note the offset values for the axis that triggered the alarm (e.g., +X, +Z).

Take a photo of the current offset values before making changes for easy reference or rollback.

Ensure the machine is in a safe state before navigating menus to avoid accidental movement.

Compare Against Stroke Limit

Cross-reference the offset value with the stored stroke limit for that axis (parameter 1320 for +X, 1324 for +Z, etc.) via the SYSTEM > PARAMETER screen. Calculate if the programmed position plus offset exceeds the limit.

Use a calculator to add the offset and programmed position to confirm the total exceeds the limit.

Do not modify parameters yet; only observe values to avoid unintended changes.

Adjust Offset Value

If the offset is too large, reduce the positive value in the OFFSET SETTING screen to bring the total position within the stored stroke limit. Test by jogging the axis or running a small program segment in MDI mode.

Make small incremental changes (e.g., reduce by 10-20% of the excess) and test to avoid over-correcting.

Verify no collision risk with fixtures or tools before jogging the axis.

Access Stroke Limit Parameters

Go to SYSTEM > PARAMETER on the control panel and locate parameters 1320-1327 for the positive and negative limits of each axis. Note the value for the axis that triggered the alarm (e.g., 1320 for +X).

Write down the current values before any changes to revert if needed.

Ensure parameter write is disabled (parameter 0000 bit 0 = 0) during initial observation.

Compare with Specifications

Refer to the machine’s technical manual or travel specification plate to confirm the mechanical travel limits. Check if the stored stroke limit is set significantly lower than the actual mechanical limit.

If the manual is unavailable, contact the machine manufacturer for the correct travel specs.

Never set limits beyond mechanical specifications to avoid hardware damage.

Modify Stroke Limit

Enable parameter write mode (set parameter 0000 bit 0 = 1), adjust the relevant stroke limit parameter to a value closer to but not exceeding the mechanical limit, then disable write mode. Test by jogging the axis to the new limit.

Increase the limit in small increments (e.g., 5-10 mm) and test to ensure safety.

Double-check for collision risks with table edges or tool changers before testing.

Locate Alarm Line in Program

Access the program via the EDIT screen and scroll to the line where the alarm was triggered (noted on the alarm screen). Look for G90 commands with large positive coordinate values.

Use the alarm history log if the exact line isn’t clear to pinpoint the error.

Do not run the program until the issue is identified to avoid further alarms.

Calculate Total Position

Add the programmed coordinate value to the active work offset for that axis (from OFFSET SETTING screen). Compare the sum against the stored stroke limit (parameter 1320-1327).

Document the calculation on paper or a notepad for clarity during troubleshooting.

Ensure calculations are accurate to avoid misdiagnosis.

Modify Program or Offset

Either edit the program to reduce the absolute coordinate value or adjust the work offset to ensure the total position falls within the stroke limit. Test the modified program in MDI mode for a single block.

If unsure, simulate the program in dry run mode to verify safe travel.

Check for potential collisions before running any test movements.

Check Reference Return Behavior

Attempt a manual reference return (G28) for the affected axis and observe if the machine moves to an unexpected position or triggers the alarm again. Note the machine coordinate after return.

Use a low feedrate override (10-25%) during reference return to monitor movement closely.

Ensure no obstacles are in the path during reference return to prevent crashes.

Verify Reference Point Parameters

Access parameters 1240-1247 (reference point coordinates) via SYSTEM > PARAMETER and compare against the machine manual or previously documented values. Look for deviations or zeroed-out values.

If values are lost, check maintenance logs for the last known good settings.

Do not modify parameters without confirming correct values to avoid further issues.

Re-establish Reference Point

If parameters are incorrect, perform a manual reference return procedure as per the machine manual, or re-enter the correct values for 1240-1247 in parameter write mode. Test by jogging and running a small program.

After resetting, mark the physical reference position with a dial indicator for future verification.

Verify all axes are clear of fixtures or tools before testing movements.

Check Tool Offset Values

Navigate to the OFFSET SETTING screen and locate the active tool offset number. Note the Z-axis tool length offset value and check if it’s unusually large and positive.

Compare the value against typical tool lengths used on this machine for a quick sanity check.

Ensure the machine is stopped before navigating menus to avoid accidental activation.

Review Program for G43

Open the program in EDIT mode and search for G43 commands activating the tool length offset. Calculate the total Z position by adding the tool offset, work offset, and programmed Z value, then compare against parameter 1324 (+Z limit).

Use the search function on the control to quickly locate G43 codes in long programs.

Double-check calculations to ensure accurate diagnosis.

Adjust Tool Offset or Program

If the tool offset is incorrect, measure the tool length again using a tool setter or manual method and update the offset value. Alternatively, adjust the programmed Z value or work offset to stay within limits. Test in MDI mode.

Recalibrate all tool offsets periodically to prevent cumulative errors.

Verify no collision risk with the workpiece or fixtures before testing Z-axis movement.