26011

Navigate to Diagnostics > Machine Data > Axis-Specific > [Axis Name] > QEC Parameters in the SINUMERIK operator panel or via HMI machine data editor.

Do not confuse QEC machine data with general servo tuning parameters (MD 32000 series).

Verify MD 36050, MD 36051, and MD 36052 are set to valid values (typically 50-500ms per QEC application). Cross-reference your machine documentation for OEM-recommended settings.

If values are missing or invalid, enter manufacturer-specified measuring times. Standard industrial practice: 100-200ms for MD 36050 (coarse criterion), 50-100ms for secondary criteria.

Changes to MD values require NCK reset (Ctrl+Shift+R) and axis rehoming before QEC function activates.

Save machine data changes and clear alarm memory. Perform a controlled test move (G00 with velocity reversal) to verify QEC measuring period is now accepted.

Access Diagnostics > Machine Data > Axis-Specific > [Axis Name] > QEC Activation Criteria in the control panel.

Confirm MD 36040 and MD 36041 contain valid error thresholds (in encoder counts or microns, depending on configuration). Typical range: 10-100 counts for servo systems.

If criteria are zero or missing, consult the machine's commissioning manual and enter OEM-specified values. These thresholds determine when position error triggers the measuring period start.

QEC criteria must be less than maximum servo error limits (MD 33000 series) to prevent masking of genuine axis faults.

After correction, save data, reset NCK, and verify QEC activation during a test cycle with intentional velocity reversals.

Navigate to Diagnostics > Machine Data > NCK General > Axis Configuration. Verify MD 30001 for the affected axis shows axis type supporting dynamic error compensation (typically axis type 1 or 2 with servo).

Axis type changes require full NCK reconfiguration and DFS (Distributed Function Safety) re-commissioning on safety-relevant systems.

Check MD 36000 (QEC_ENABLE) - must be set to 1 (enabled). If 0, QEC function is disabled and measuring time parameters are ignored, triggering the alarm.

If QEC was intentionally disabled, either re-enable it (MD 36000 = 1) with valid measuring times, or suppress alarm 26011 via alarm masking if QEC is not required.

Only mask alarms if QEC is documented as not needed for this axis. Masking without commissioning data is a safety and quality risk.

After enabling QEC or correcting axis configuration, perform a full startup: NCK reset → axis reference → test move with velocity reversal to confirm alarm clears.