239-004B

Power down system safely

Execute emergency stop, wait for all motion to cease, then power down the TNC control and drive system completely.

Ensure all axes are mechanically secured before powering down

Verify encoder cable connections

Check encoder feedback cables at both motor and drive amplifier ends. Compare physical connections against the axis assignment diagram in the machine documentation.

Use a flashlight and magnifying glass to inspect connector pin alignment and potential bent pins

Cross-reference cable labeling

Verify cable labels match the axis designations shown in the alarm message. Check that X-axis encoder cable connects to the X-axis drive channel.

Take photos before disconnecting any cables for reference

Test axis movement after reconnection

Power up system, clear alarms, and manually jog each axis in MOD mode to verify correct motor responds to each axis command.

Use very small incremental moves initially to prevent crashes

Access axis configuration menu

Navigate to MOD → CfgAxisMotor → select the affected axis from the alarm message to review motor configuration parameters.

Write down current parameter values before making changes

Verify motor type and encoder settings

Check motorType, encoderType, and encoderResolution parameters match the physical motor nameplate specifications and encoder documentation.

Incorrect encoder resolution can cause severe positioning errors

Validate axis assignment parameters

Confirm axisNumber and motorChannel parameters correctly map the logical axis to the physical drive channel and motor connection.

Cross-reference with the drive system configuration documentation

Save configuration and restart

Save parameter changes, perform a complete TNC restart, and verify the alarm clears during the initialization sequence.

Access drive configuration interface

Connect to the drive system configuration software (typically via Ethernet) and navigate to the axis assignment configuration section.

Ensure you have the correct drive configuration software version for your hardware

Verify drive channel mapping

Check that drive channel assignments match the TNC axis configuration. Axis X should map to drive channel X, etc.

Incorrect drive mapping can cause multiple axes to move unexpectedly

Review FS configuration in drive

Verify the Functional Safety configuration in the drive matches the TNC FS settings, particularly the axis monitoring assignments.

Document any changes made to drive parameters for future reference

Synchronize TNC and drive configurations

Ensure both TNC CfgAxisMotor parameters and drive axis assignments are consistent, then restart both systems to reinitialize the FS connection.

Check encoder signal quality

Use TNC diagnostic screens (MOD → Diagnosis → Encoder) to monitor encoder signal strength and error counters for the affected axis.

Look for intermittent signal dropouts or high error counts that indicate cable issues

Perform encoder cable continuity test

With power off, use a multimeter to test continuity and insulation resistance of all encoder cable conductors from motor to drive connection.

Ensure proper lockout/tagout procedures before testing cables

Inspect encoder mechanical coupling

Check encoder coupling at the motor for looseness, damage, or contamination that could cause position feedback errors.

Look for metal shavings or coolant contamination in the encoder area

Replace encoder cable or encoder

If testing reveals cable or encoder faults, replace the defective component and recalibrate the axis reference position.

Encoder replacement requires axis reference point recalibration

Access FS configuration menu

Navigate to MOD → CfgFunctionalSafety to review the safety system configuration for axis monitoring and motor assignments.

FS configuration changes typically require special access codes

Verify FS axis monitoring settings

Check that FS monitoring is properly configured for each axis and matches the physical motor installation and safety requirements.

Incorrect FS settings can disable safety monitoring or cause false alarms

Review safety validation parameters

Confirm FS validation thresholds and timing parameters are appropriate for the motor and drive system response characteristics.

Consult machine builder documentation for recommended FS parameter values

Reinitialize FS system

After correcting FS configuration, perform a complete system restart to reinitialize the safety monitoring and clear validation errors.