6422

Navigate to Diagnostics > Machine Data > Tool Changer section. Verify MD 31000 'Number of Magazines' matches the physical tool changer configuration.

Check MD 31020 onwards for magazine-specific parameters (magazine type, capacity, position offsets). Ensure the magazine number %2 from the alarm is present and configured with valid parameters.

Do not modify machine data without backup; use parameter export function first.

Reload machine data using Siemens SINUMERIK HMI: System > Settings > Load Machine Data or restart NCK (warm restart via HMI menu).

Retry the tool change command via MDI or part program. Verify alarm clears and tool motion executes.

Access the PLC program monitoring via Diagnostics > PLC > Online. Navigate to the tool changer DB (commonly DB31 or custom Tool_Changer DB) and verify the magazine availability/enable flag for magazine %2 is set to TRUE.

Check both the PLC retain memory and the current runtime state; power cycle may have reset flags.

Verify in the MMC operator panel or Service > Diagnostics > Tool Changer Status that magazine %2 shows 'Ready' or 'Available'. If status is 'Error' or 'Offline', check the PLC alarm/error log (Diagnostics > PLC > Errors).

If PLC shows magazine error, reset the tool changer subsystem via the HMI 'Reset Tool Changer' function or manually reset the magazine enable bit in the PLC. Verify encoder/sensor feedback on the physical magazine if available.

Physical magazine may have a hardware fault (motor, proximity sensor); verify mechanically before software reset.

Reissue the tool change command and confirm alarm 6422 no longer appears.

Review the part program line triggering alarm 6422. Extract the tool number or magazine reference. Cross-reference the tool table (Service > Tool Management > Tool Data) to verify which magazine is assigned to that tool.

Check MD 31030 onwards (Tool-to-Magazine assignment) and verify the tool magazine location pointers are correctly defined. Ensure magazine number %2 is a valid index (typically 1-N where N = total magazines configured in MD 31000).

Magazine numbering is 1-based in SINUMERIK; verify offset is not 0-based in part program logic.

If using custom M-macro for tool change, inspect the macro source (Service > Programs > Macro) for hardcoded or calculated magazine parameters. Verify macro passes correct magazine index to NCK function block.

Correct the part program magazine reference or tool assignment in the tool table, then re-execute the tool change command.