26026

Access the SINAMICS drive parameter set via Siemens KTP mobile panel, STARTER software, or integrated commissioning interface. Navigate to Parameter P2038 for the affected axis drive.

Do not modify drive parameters while machine is in motion or powered to the main drive spindle.

Verify P2038 is set to SIMODRIVE 611 universal mode. Typical correct values are P2038=2 (SIMODRIVE 611 universal, 16-bit) or equivalent for your SINAMICS generation. Consult the drive's parameter manual (e.g., SINAMICS S120 parameter list) for the exact enumeration.

If P2038 shows an incorrect value, change it to the SIMODRIVE 611 universal setting appropriate for your system configuration. Power cycle the drive and NCK to apply changes.

Power cycling will interrupt production; schedule during maintenance window.

After correcting P2038, clear alarm 26026 via the 840D operator interface (RESET or alarm acknowledgment key) and re-enable axis motion. Verify axis responds to NCK commands without recurrence.

Check the drive firmware version and SINUMERIK 840D NCK software version for compatibility. Use STARTER or the Siemens commissioning tool to display firmware levels on both sides.

Load the correct parameter backup file (typically stored on the PCMCIA card or USB in the 840D) for the axis drive. Use Tools > Drive > Parameter > Load from File in the NCK commissioning menu.

Ensure backup file matches the exact SINAMICS model (S120, S110, etc.) and drive module ID to avoid parameter conflicts.

Alternatively, manually re-commission the drive by setting P2038 and related interface parameters (P2000, P2001 for enable/ready signals) according to the 840D system wiring diagram and drive manual.

Save parameters to the SINAMICS drive memory and reset. Verify alarm 26026 is no longer triggered and axis motion is smooth.

In the 840D Parameterization menu (Operate > Axis > Parameter), verify that the axis control parameters (MD1000 series for axis data) match the SIMODRIVE 611 universal bit layout. Check MD1008 (axis enable delay) and MD1009 (axis disable delay) for reasonable values (typically 100-200 ms).

Review the PLC interface database (typically DB axis or similar) in the 840D program to confirm control and status word bit definitions match P2038 protocol. Cross-reference with the drive manual's control word table for SIMODRIVE 611.

Incorrect bit assignments can cause unexpected axis behavior or safety violations; verify against machine documentation before applying changes.

If discrepancies are found, update the PLC/NCK interface data and recompile the PLC program. Download the updated program to the 840D and perform an axis enable/disable cycle.

Monitor the axis control word (via Diagnostics > Axis or SINUMERIK HMI display) and confirm proper bit transitions during enable/disable; alarm 26026 should not recur.