230-046D

Check machine parameter MP7500

Access MOD function, select machine parameters, navigate to MP7500 series and verify the PLC input number assigned for axis group enabling.

Document the current MP7500 value before making changes for rollback purposes

Verify IOC file configuration

Access PLC program via MOD function, check IOC file to ensure the input number from MP7500 is properly configured with correct signal type and polarity.

Backup IOC file before making modifications

Validate signal assignment

In PLC status display, monitor the input signal state and verify it matches the expected logic level for axis group enabling.

Use PLC trace function to monitor signal transitions during enable/disable cycles

Update IOC configuration if needed

Modify IOC file to include missing input definition or correct existing configuration, then restart TNC to load new configuration.

Check PLC input status

Access PLC program via MOD function, go to PLC status and monitor the input signal assigned to axis group enabling in real-time.

Compare input status with external device state to identify signal path issues

Measure input voltage

Use multimeter to measure voltage at TNC input terminals corresponding to axis group enable signal, verify 24VDC presence when enabled.

Ensure proper lockout/tagout procedures before accessing electrical connections

Trace signal path

Follow wiring from external enable device through terminal blocks to TNC input card, checking for loose connections or damaged cables.

Check intermediate relays or contactors that may be in the signal path

Test input card functionality

Apply known good 24VDC signal directly to input terminal and verify PLC status shows correct state change.

Review axis group parameters

Access MOD function, check MP1010-MP1013 to verify axis assignments to groups match machine configuration and PLC program expectations.

Cross-reference with machine documentation to confirm intended axis grouping

Validate group enable logic

Check MP7500 series parameters to ensure axis group enable inputs are correctly assigned to match the groups defined in MP1010-MP1013.

Test individual axis enables

Temporarily modify parameters to test individual axis enabling to isolate which specific axis or group is causing the alarm condition.

Only modify one parameter at a time and document changes for proper restoration

Synchronize PLC program

Update PLC program logic to match corrected axis group configuration and ensure proper signal routing to enable inputs.

Analyze PLC program logic

Access PLC program via MOD function, review the logic blocks handling axis group enabling, particularly around the output signals to TNC.

Look for timer delays or interlocks that might prevent proper enable signal generation

Check PLC variable assignments

Verify that PLC variables used for axis group enabling are correctly mapped to physical outputs and match IOC file definitions.

Monitor PLC execution

Use PLC trace function to monitor program execution during axis group enable sequence, identifying where logic fails.

Set breakpoints at critical logic branches to step through enable sequence

Correct PLC logic

Modify PLC program to fix identified logic errors, ensuring proper axis group enable signal generation and timing.