230-041B

Check DriveOffGroup status

Navigate to MOD > System Info > Axis Status and verify which axes are disabled by DriveOffGroup.

DriveOffGroup status is shown with 'DOG' indicator next to axis name

Clear DriveOffGroup

Execute DriveOnGroup command from PLC or use manual axis enable in Service menu to reactivate the drive group.

Ensure machine is in safe position before re-enabling drives

Verify PLC logic sequence

Check PLC program to ensure DriveOnGroup is called before individual axis enable commands.

Add interlock in PLC to prevent axis enable while DriveOffGroup is active

Review PLC timing

Check PLC program for delays between DriveOffGroup and subsequent axis enable commands. Minimum 100ms delay recommended.

Use TNC feedback signals to confirm DriveOffGroup completion before enabling axes

Modify PLC sequence

Add timer or status check in PLC to ensure DriveOffGroup is fully processed before axis enable.

Test modified PLC logic thoroughly in manual mode first

Monitor axis status feedback

Use TNC axis status feedback signals in PLC logic to confirm proper sequencing of drive group operations.

Check MP7500 settings

Navigate to MOD > Machine Parameters and review MP7500.x for each axis to verify correct drive group assignments.

MP7500 = 0 means axis is not assigned to any drive group

Verify group consistency

Ensure all axes that should operate together have the same MP7500 group number assignment.

Backup machine parameters before making changes

Test group operation

After parameter changes, test DriveOffGroup and DriveOnGroup functions manually to verify proper operation.

Perform TNC restart

Execute controlled TNC restart to reset internal state machines and clear any software conflicts.

Ensure machine is in safe state and all programs are saved before restart

Check TNC software version

Navigate to MOD > System Info > Version and verify TNC software version. Update if known issues exist with drive group handling.

Contact Heidenhain support if recurring issues with specific software versions

Clear alarm history

After restart, clear alarm history and test drive group operations to ensure proper state machine operation.

Check hardware enable inputs

Verify all hardware axis enable inputs on the TNC using MOD > Diagnosis > PLC Inputs display.

Look for stuck or intermittent enable signals that may conflict with software commands

Inspect wiring connections

Check physical connections to axis enable inputs for loose connections or damaged wiring.

Power down system before inspecting electrical connections

Test signal integrity

Use oscilloscope or multimeter to verify clean enable signal transitions and proper voltage levels.