230-050D

Check Reference Status

Press POS key and verify the REF column shows asterisks (*) for all axes. Missing asterisks indicate unreferenced axes.

The position display will show question marks (?) for unreferenced axes in older TNC versions.

Execute Reference Run

Select Manual mode, press REF key, then press NC START to reference all axes. Ensure reference switches are functioning properly.

Clear the work area before referencing - axes will move to reference positions automatically.

Verify Software Limits

After referencing, check machine parameters MP1010-MP1013 (software limit switches) are properly configured for each axis.

Software limits should be set slightly inside the hardware limit switch positions for safety margin.

Access Machine Parameters

Press MOD key, enter machine parameter mode, navigate to MP1010-MP1013 for the affected axis to check software limit values.

Machine parameter access requires appropriate user permissions and password.

Compare Actual vs Limit Positions

Note current axis position from POS display and compare with MP1010 (negative) and MP1013 (positive) limit values. Position should be within these limits.

Use incremental coordinates (INCR) to see relative position from reference point.

Adjust Software Limits

If limits are incorrect, modify MP1010/MP1013 values to proper machine travel limits, then cycle power or reset to activate new parameters.

Verify new limits with machine drawings - incorrect limits can cause crashes.

Test Reference Switch Function

In Manual mode, slowly jog axis toward reference switch while monitoring PLC inputs. Check that reference switch input activates properly.

Use the PLC status display (PLC key) to monitor reference switch inputs in real-time.

Check Reference Switch Parameters

Verify MP1020 (reference switch input assignment) and MP1030 (reference direction) are correctly configured for the affected axis.

Incorrect reference direction can cause axis to drive away from switch during reference run.

Inspect Physical Switch

Check reference switch mounting, wiring connections, and mechanical operation. Clean switch actuator and verify proper gap settings.

Proximity switches typically require 1-2mm gap; mechanical switches need proper preload for reliable operation.

Check Encoder Status

Monitor encoder signals in the diagnostic display. Look for encoder error messages or unstable position readings during movement.

Use the oscilloscope function in TNC diagnostics to view encoder signal quality in real-time.

Verify Encoder Parameters

Check MP1100-MP1120 encoder configuration parameters match the installed encoder specifications (resolution, type, interface).

Incorrect encoder parameters can cause position errors and potential machine crashes.

Test Encoder Cables

Inspect encoder cable connections at both motor and TNC ends. Check for proper shielding, bent pins, or cable damage that could affect signal integrity.

Encoder cables should be routed away from power cables and properly secured to prevent flexing damage.

Review PLC Program

Check PLC program for custom reference sequences or modifications to standard limit switch monitoring logic that might interfere with normal operation.

Look for custom M-functions or cycles that might override standard referencing procedures.

Check Software Options

Verify software options and feature licenses are properly configured. Some limit monitoring features require specific software options to be enabled.

Changing software options may require TNC restart and could affect other machine functions.

Reset to Default Configuration

If custom programming is suspected, temporarily load default PLC program or machine parameters to isolate the issue.

Backup all custom programs and parameters before loading defaults - machine-specific settings will be lost.