4027

Access Siemens HMI or SINUMERIK Operate panel and navigate to Maintenance → Machine Data. Identify which MD parameter was modified (shown in alarm message parameter %1, e.g., MD10100).

Verify the axis container assignment by checking MD32100 (AXIS_NAME_TAB) and MD32110 (AXIS_TYPE) for the affected axis. Confirm the container affiliation in the NCK configuration.

Review the change log in the HMI or use Siemens SINUMERIK ProDiag to confirm which sibling axes received the synchronized MD value. Cross-check MD parameters across all axes in the container to ensure consistency.

If asymmetric axis behavior is required, the axis must be removed from the container or the MD must be explicitly configured as axis-specific (non-container-linked) in the system configuration.

If the synchronized change was unintended, use the HMI undo function or manually restore the previous MD value only to the target axis, then modify the NCK configuration to prevent container-level linkage for that parameter.

Check the axis container definition in the NCK configuration (accessible via Siemens SINUMERIK Operate → Maintenance → NCK Configuration or via SINUMERIK Automation Tool). Identify the container name and all member axes.

Examine MD10050 and MD10060 values for the modified axis and compare against all sibling axes to confirm synchronization. These MDs control reference point and measurement offsets critical to coordinated motion.

Misaligned reference offsets in coupled axes can cause position errors during coordinated interpolation or result in machine crashes.

If the change was intentional (e.g., updating reference offsets after mechanical recalibration), verify that the synchronized values are correct for all axes by performing a SINUMERIK dry-run test and comparing actual vs. commanded positions.

If individual axis tuning is required, consult the machine builder's documentation to determine whether container membership should be modified or if axis-specific MD variants exist for decoupling.

If using SINUMERIK Automation Tool, review the recent configuration export/import logs or batch operations. Check the automation tool's change history (typically available in the tool's application log or database audit trail) to identify which MD was modified and when.

Verify that the remote configuration change was authorized by checking access control logs on the Siemens HMI. Use Maintenance → Event Log (or SD logs) to timestamp the alarm 4027 occurrence and correlate it with configuration service activities.

If the change was unplanned or unauthorized, immediately revert the MD to the previous known-good value using the HMI backup or by manually restoring from version control. Document the incident for security audit purposes.

Unauthorized remote configuration changes may indicate security compromise; verify network integrity and update HMI credentials.