231-C2A0

Access Machine Parameters

Navigate to MOD function, enter machine parameter mode with MP7411 (access level), then go to CfgAxisHardware configuration.

Document current settings before making changes

Verify selectEncoderIn Parameter

Check the selectEncoderIn value for the affected axis - ensure it matches available encoder input channels (typically 0-7 for most TNC systems).

Incorrect encoder assignment can cause axis runaway

Correct Invalid Entry

Set selectEncoderIn to the correct encoder input channel number based on hardware wiring documentation and axis configuration.

Cross-reference with electrical drawings to verify physical connections

Restart Control System

Perform complete power cycle of TNC control to reload configuration parameters and clear internal software error state.

Backup Current Configuration

Use PGM MGT to backup current machine parameters and configuration files to external storage before attempting repairs.

Always backup before configuration restoration

Restore Configuration Backup

Load a known good configuration backup from PGM MGT, focusing on CfgAxisHardware section and related encoder parameters.

Use the most recent backup that was working properly

Verify Encoder Configuration

Check all encoder-related parameters in CfgAxisHardware including selectEncoderIn, encoder type, and resolution settings for consistency.

Compare with machine documentation to ensure all settings match specifications

Test Axis Movement

Perform controlled axis movement tests in manual mode to verify encoder signals are being read correctly after configuration restoration.

Verify Physical Connections

Check encoder cable connections at both encoder and TNC control end, ensuring proper connection to the channel specified in selectEncoderIn parameter.

Power down system before checking connections

Check Encoder Interface Cards

Verify encoder interface cards are properly seated and functional, check LED status indicators on encoder input modules.

Swap encoder cables between channels to isolate hardware issues

Update Configuration to Match Hardware

Modify selectEncoderIn parameter in CfgAxisHardware to match actual physical encoder connection if wiring is correct but configuration is wrong.

Document any changes for future reference

Validate Encoder Signals

Use TNC diagnostic screens to monitor encoder signal quality and verify proper A/B quadrature signals are being received.

Check Software Version

Navigate to MOD function and check current TNC software version, compare with previous version before alarm occurrence.

Document software versions for troubleshooting history

Review Software Release Notes

Check Heidenhain software release documentation for changes to encoder configuration parameters or CfgAxisHardware structure.

Software changes may require parameter migration

Update Configuration Format

Modify encoder configuration parameters to match new software requirements, ensuring selectEncoderIn uses correct format and range.

Contact Heidenhain support for parameter migration guidance

Validate New Configuration

Test all axis movements and encoder functionality to ensure updated configuration works properly with new software version.

Check System Memory Status

Access TNC diagnostic functions to check internal memory status and look for memory-related error messages or warnings.

Memory errors can cause unpredictable system behavior

Perform Memory Test

Run TNC built-in memory diagnostic tests if available, or observe system behavior for signs of memory corruption during operation.

Memory issues often show intermittent symptoms

Replace Configuration Storage

If memory errors are confirmed, replace TNC internal storage device (CF card or SSD) and restore configuration from backup.

Ensure proper ESD protection when handling storage devices

Monitor System Stability

After storage replacement, monitor system for recurring configuration errors or other signs of hardware instability.