230-04D2

Access Machine Parameters

Enter MOD function, select 'Machine Parameters', navigate to the axis-specific parameters MP720-MP799 for the affected axis shown in the alarm text.

Use the search function in MOD mode by entering 'MP7' to quickly filter axis-related parameters.

Verify Mandatory Axis Parameters

Check that MP720 (axis name), MP730 (axis type), MP740 (reference point), MP750 (software limit switches), and MP760 (feed rate limits) are all properly defined and contain valid values.

Do not modify parameters without documenting original values. Incorrect changes can cause axis runaway or collision.

Compare with Parameter Documentation

Cross-reference current parameter values against the machine manufacturer's parameter list or Heidenhain TNC installation manual for your specific control version.

Most parameter errors show in the error log with specific MP numbers—check the detailed error log entry before making changes.

Restore from Backup

If parameters appear corrupted, restore axis parameters from the most recent verified backup using MOD > Backup/Restore function, selecting only the affected axis parameters.

Always create a new backup before restoring to allow rollback if the backup is also corrupted.

Review Gantry Axis Assignment

In MOD > Machine Parameters, locate MP7140 series for the affected axis. Verify master axis and slave axis definitions match the mechanical configuration.

MP7141.x defines the slave axis for each master—ensure both master and slave reference each other correctly.

Check Motion Limit Consistency

Verify that MP750 (software limits) and MP760 (maximum feedrates) are identical for both master and slave axes in a gantry pair.

Mismatched limits between gantry axes can cause the control to reject the configuration as unsafe.

Validate Synchronization Parameters

Check MP7142.x (gantry synchronization tolerance) and MP7143.x (synchronization monitoring) are properly set and within reasonable values for your mechanical system.

Typical sync tolerances are 0.01-0.05mm for precision machines. Values of zero or excessively large numbers often indicate configuration errors.

Verify Axis Type Parameter

Check MP730.x for the affected axis. Value should be 0 for linear axes, 1 for rotary display ±180°, or 2 for rotary modulo 360°. Ensure this matches the physical axis.

C-axes (rotary tables/spindles) must be type 1 or 2; X/Y/Z must be type 0. Mixed configurations cause immediate rejection.

Check Modulo Settings for Rotary Axes

If MP730 indicates rotary axis (1 or 2), verify MP731 (modulo range) and MP732 (display mode) are properly configured. For linear axes, these parameters must not be set.

Setting modulo parameters on a linear axis or omitting them on a rotary axis will trigger configuration fault.

Validate Reference Point Configuration

Check MP740.x (reference point) is appropriate for axis type. Rotary modulo axes require specific reference strategies different from linear axes.

MP740=0 is common for linear axes with reference marks; rotary axes often use MP740=1 or 3 depending on encoder type.

Check Software Version Compatibility

In MOD > Version Information, note the current software version. Review Heidenhain release notes for parameter changes between your previous and current software versions.

Major version changes (e.g., 340590 to 617xxx) often require parameter conversion utilities available from Heidenhain.