What causes Siemens SINUMERIK alarm 4033?

Machine data was changed requiring acknowledgment or power cycle. System configuration change notification. Commissioning or service operation generated this notice. Axis or drive configuration change affecting machine data.

How do I fix Siemens SINUMERIK alarm 4033?

1. Read the complete notice text on the SINUMERIK screen. 2. If a power cycle is indicated, perform a controlled machine power off and restart. 3. If machine data backup is indicated, save the current machine data. 4. Acknowledge the notice and verify the system is operating correctly after the change. 5. Consult the machine commissioning engineer if the notice is unexpected.

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Siemens SINUMERIK Controller

Communication · Intermediate · 30-120 minutes

Alarm 4033

Siemens 840D 4033 - NOTICE! NCU link communication still not connected

Alarm 4033 indicates that NCU link communication initialization failed because prerequisite system alarms are blocking the communication handshake during boot sequence. The NCK cannot establish the NCU-PLC data link until all blocking alarms are cleared, typically cycle time modification alarms like 4110 that require parameter recalculation.

Siemens SINUMERIKCommunicationIntermediate30-120 minutes

4033

Siemens 840D 4033 - NOTICE! NCU link communication still not connected

NOTICE! NCU link communication still not connected

Root Cause Summary

Alarm 4033 indicates that NCU link communication initialization failed because prerequisite system alarms are blocking the communication handshake during boot sequence. The NCK cannot establish the NCU-PLC data link until all blocking alarms are cleared, typically cycle time modification alarms like 4110 that require parameter recalculation.

Safety

Refer to Siemens documentation
Ensure qualified technician performs repairs

Causes and Fixes

1
Access Diagnostics menu: NCK > Alarms > Active Alarms. Document all active alarms in the queue, particularly alarm 4110 or cycle time-related alarms (41xx range).
2
Navigate to Parameters menu: NCK > MD > MD 32100 (CYCLE_TIME_ROUGH_MAIN) and MD 32110 (CYCLE_TIME_FINE_MAIN). Verify values match machine specification sheet and are not showing modified/auto-corrected indicators.
Do not manually edit cycle time parameters without stopping the system and consulting machine documentation.
3
If alarm 4110 is active, clear it by confirming the NCK cycle time adjustment, then perform a soft reset via Machine > Reset or power cycle the control to reinitialize NCU link communication.
4
Verify alarm 4033 clears automatically within 30 seconds post-reset. If alarm persists, escalate to check for corrupt startup files or corrupted machine data backup.

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