What causes Siemens SINUMERIK alarm 6020?

Parameter or machine data configuration error. Hardware fault on the NC or drive component. Part program error or illegal command. Communication fault between NC and drive or I/O modules. Software or firmware error requiring system restart.

How do I fix Siemens SINUMERIK alarm 6020?

1. Note the complete alarm text including any axis, channel, or block number values. 2. Check for related alarms active simultaneously in the SINUMERIK alarm list. 3. Power cycle the machine to clear transient faults. 4. Review the SINUMERIK machine data for parameters related to the alarm. 5. Consult the Siemens SINUMERIK alarm manual for alarm 6020 detailed remedy.

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Siemens SINUMERIK Controller

Parameter · Intermediate · 30-120 minutes

Alarm 6020

Siemens 840D 6020 - Machine data have been changed - now memory is reorganized

Alarm 6020 fires when machine data parameters affecting NC user memory allocation (MD10100-MD10110 range) have been modified, triggering automatic memory reorganization by the NCK data management system. This is an informational alarm indicating successful memory restructuring, not a critical fault, but confirms that MD changes have altered the memory layout.

Siemens SINUMERIKParameterIntermediate30-120 minutes

6020

Siemens 840D 6020 - Machine data have been changed - now memory is reorganized

Machine data have been changed - now memory is reorganized

Root Cause Summary

Alarm 6020 fires when machine data parameters affecting NC user memory allocation (MD10100-MD10110 range) have been modified, triggering automatic memory reorganization by the NCK data management system. This is an informational alarm indicating successful memory restructuring, not a critical fault, but confirms that MD changes have altered the memory layout.

Safety

Refer to Siemens documentation
Ensure qualified technician performs repairs

Causes and Fixes

1
Access Machine Data Editor: Select 'Diagnostics' > 'Machine Data' > navigate to MD10100/MD10101 in the '1' (General) category to verify recent changes to memory allocation parameters.
2
Document the current values and compare against system documentation. Standard values typically range MD10100: 200000-500000 bytes (NCK memory) and MD10101: 100000-300000 bytes (program memory) depending on system configuration.
3
Confirm alarm clears automatically after one cycle or power cycle. If alarm persists beyond one startup sequence, check error log via 'Diagnostics' > 'Alarms' for secondary error messages indicating memory corruption.
Do not modify MD10100/MD10101 during active program execution or during memory-intensive operations (large file transfers).
4
If changes were unintended, restore backup Machine Data file from known-good state using 'Utilities' > 'Backup/Restore' and perform cold restart (POWER ON/OFF cycle).

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