126-011D

Perform clean system restart

Ensure Emergency Stop is released. Power down the complete system using the main disconnect. Wait minimum 30 seconds for all capacitors to discharge. Power up and allow the TNC to complete its full boot sequence without any interruption—do not press any keys or activate E-Stop during HSCI initialization phase (typically 30-90 seconds).

Do not interrupt the boot sequence once started. Wait for the TNC to reach the normal operating screen or error state.

Monitor HSCI initialization

During boot-up, observe the TNC screen for HSCI initialization messages. The control will display status of each HSCI component as it completes self-test. Note if the component at address %3 is listed and whether it completes or times out.

Press MOD key → Info → Boot Log to review the complete startup sequence and identify at which point the component failed to respond.

Verify alarm clearance

After successful uninterrupted boot, check if alarm 126-011D clears automatically. If cleared, perform a test cycle of all axes to verify normal operation. Document the incident and monitor for recurrence.

If this alarm occurs repeatedly at startup, suspect hardware issues rather than initialization timing problems.

Access HSCI component diagnostics

Press MOD key → System → HSCI Configuration. Locate the component at address %3 in the HSCI device list. Check the status field—it should show 'Ready' or 'Operational'. If it shows 'Not Initialized', 'Self-Test Pending', or 'Unknown', the component requires commissioning.

Document the serial number and firmware version displayed for the component at this address for service records.

Execute component self-test

In the HSCI Configuration screen, highlight the component at address %3. Press the softkey 'Execute Self-Test' or 'Initialize Component'. The TNC will command the component to run its internal diagnostic routine. This may take 2-10 minutes depending on component type. Do not power off during this process.

Ensure all axes are in a safe position and Emergency Stop is readily accessible. Some components may cause brief motor movements during self-test.

Verify firmware compatibility

After self-test, check that the component firmware version is compatible with your TNC control version. Navigate to MOD → Info → HSCI Components and compare the firmware version against the compatibility matrix in your TNC service documentation or Heidenhain Technical Manual for your specific control version.

Firmware mismatches between TNC and HSCI components are a common cause after component replacement. Update either TNC or component firmware as needed to achieve compatibility.

Save configuration and restart

After successful self-test completion, save the HSCI configuration using the 'Save Configuration' softkey. Perform a complete control restart to ensure the new configuration is properly loaded and all components initialize correctly.

Create a backup of the machine parameters (MOD → System → Backup → Create Backup) after successful commissioning of new components.

Verify HSCI bus integrity

Access MOD → System → HSCI Diagnostics. Check the bus status for address %3. Look for communication errors, CRC errors, or timeout counters. A functioning HSCI connection should show active communication with error count at zero or very low numbers.

Use the 'HSCI Monitor' function if available on your TNC version to observe real-time communication packets to/from address %3.

Inspect physical connections

Power down the system. Inspect the HSCI cable connections at both the TNC side and the component at address %3. Ensure connectors are fully seated, locking mechanisms engaged, and no bent pins visible. Check cable shielding is properly terminated at both ends. Measure cable continuity if suspect.

Only qualified electrical personnel should work inside the electrical cabinet. Follow lockout/tagout procedures.