26101

Power down the machine and inspect the DRIVE-CLiQ connector on both the NCK interface module and drive %2. Check for bent pins, corrosion, or moisture ingress.

Ensure emergency stop is engaged and 24V DC supply is isolated before touching connectors.

Reseat the DRIVE-CLiQ cable firmly at both ends; listen for the connector click. Verify cable routing avoids high-voltage power lines and does not show visible damage, kinks, or pinch points.

If cable appears damaged, replace with a Siemens-certified DRIVE-CLiQ cable of correct length. Do not use aftermarket or third-party cables as they may not meet timing specifications.

Power up and monitor Diagnostics > Axis Status (NCK menu path: Service > Diagnostics > Axis %1) to confirm communication is re-established before resuming operation.

Access NCK menu: Diagnostics > Parameters > Machine Data (MD). Navigate to MD 32710 (encoder feedback type for axis %1) and MD 32700 (drive assignment) and verify they match the physical drive configuration and encoder installed.

Do not modify parameters without documenting original values; use SINUMERIK backup function first.

Check drive ID (typically hard-coded or DIP switch set) against the NCK drive assignment table. Confirm axis %1 is mapped to drive %2 in the Axis > Drive Assignment dialog or via HMI parameter pages.

Review alarm log (Service > Alarms > Archive) for preceding alarms such as 26050 (encoder not ready) or 26070 (drive parameter error) that may indicate parametric corruption.

Power-cycle the control (full 24V DC reset, 10-second wait) and re-initialize drive communication via Service > Drive > Initialization or automatic boot sequence. Verify 26101 does not reappear.

Measure 24V DC supply voltage at the drive module connector (pin 1 and GND) using a multimeter. Voltage must be between 24V ±10% (21.6-26.4V). If below 21.6V, investigate power supply capacity or distribution wiring.

Use only a calibrated multimeter and ensure proper grounding probe placement to avoid false readings.

Check for corroded or loose 24V DC terminals at the power distribution block. Inspect fuses or circuit breakers serving the drive circuits; replace any blown or tripped devices and confirm amperage rating matches drive requirements (see drive nameplate).

If multiple axes show 26101 simultaneously, the shared 24V supply is likely the culprit. Verify the main 24V power supply unit (PSU) output current rating is sufficient for total axis count. Consider installing a larger PSU or dedicated supply.

After correcting supply voltage, perform a control cold start (Service > System > Reset) to clear communication fault flags and re-establish DRIVE-CLiQ link.