231-C022

Access Safety Configuration Directory

Use MOD function with authorized password, navigate to File Management, and browse to TNC:/sys/SafetyPLC/ or TNC:/sys/SMB/ to verify presence and integrity of configuration files (SafeConfig.xml, SafetyPar.saf, or similar).

Only authorized and trained personnel should access safety-related files. Unauthorized changes can compromise machine safety.

Check Safety Configuration Checksum

In MOD > Safety Configuration, verify the displayed checksum value matches the documented value from commissioning documentation. Mismatch indicates configuration corruption or unauthorized modification.

Always document the safety configuration checksum during initial commissioning and keep it with machine documentation for future verification.

Restore from Backup

Navigate to TNC:/sys/backup/SafetyPLC/ and identify the most recent validated backup. Copy the backup files to the active TNC:/sys/SafetyPLC/ directory, replacing corrupted files.

Ensure the backup being restored is from the correct machine configuration and has been validated for this specific control and safety I/O setup.

Reinitialize Safety System

After restoring configuration files, perform complete power cycle (not just NC reset). Upon restart, navigate to MOD > Safety Configuration and verify configuration is accepted and checksum is correct.

If no backup exists, contact machine builder for original safety project file or use Heidenhain SafetyDeveloper software to regenerate configuration from documented parameters.

Check Component Versions

Access MOD > System Information > Component Versions and note the NC Software version, SMB firmware version, and SPL firmware version. Cross-reference with Heidenhain compatibility matrix documentation.

The safety module firmware version must be compatible with the specific NC software build number, not just the major version.

Update Safety Module Firmware

If version mismatch is identified, obtain correct SMB/SPL firmware from Heidenhain for your NC software version. Use MOD > Software Update > Component Update to flash the appropriate firmware file to the safety module.

Never interrupt power during safety firmware update. Ensure UPS backup is active. Firmware update failure may require factory service.

Reload Safety Configuration

After firmware update, the safety configuration may need to be re-accepted. Navigate to MOD > Safety Configuration, verify all parameters, and perform acceptance procedure as per commissioning guidelines.

Keep a USB backup of both the safety configuration files and the compatible firmware versions together for future maintenance.

Enter Safety Configuration Mode

Access MOD function with Safety Engineer password level. Navigate to Safety Configuration menu. Check configuration status indicator - it should show 'Accepted' not 'Pending' or 'Unvalidated'.

Safety configuration changes require proper authorization and validation according to machine risk assessment and safety standards compliance.

Review All Safety Parameters

Systematically verify each safety parameter section: Safe Inputs, Safe Outputs, Safe Motion Functions (SLS, SOS, etc.), and Safety Logic. Ensure no parameters show error flags or incomplete configuration indicators.

Use the configuration comparison function if available to compare current parameters against the master configuration from commissioning.

Perform Configuration Acceptance

After verification, execute the acceptance procedure: MOD > Safety Configuration > Accept Configuration. Enter authorization password, confirm checksum is calculated and displayed, and document the new checksum value.

The acceptance process generates a new configuration signature. This signature must be documented in the machine safety documentation for compliance purposes.

Complete Power Cycle and Verify

Perform complete control power-down for at least 10 seconds, then power up. Monitor startup messages and verify alarm 231-C022 does not reappear. Check that all configured safety functions are operational.

After safety configuration changes, perform complete functional safety testing according to machine validation protocol before returning to production.