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Siemens SINUMERIK Controller
Spindle · Intermediate · 30-120 minutes
Siemens 4160 - Invalid M function number configured for spindle switchover
Alarm 4160 is triggered when machine data $MC_SPIND_RIGID_TAPPING_M_NR is configured with an M function number that is reserved by the SINUMERIK system for standard machine control operations. The NCK firmware prevents assignment of system-reserved M codes (M1, M5, M17, M30, M40-M45) to spindle switchover functions to avoid conflicts with modal group logic and safety-critical functions.
4160
Siemens 4160 - Invalid M function number configured for spindle switchover
Invalid M function number configured for spindle switchover
An M function was specified in MD20094 $MC_SPIND_RIGID_TAPPING_M_NR in order to configure the M function number for spindle switchover. The M function number is assigned by the system and cannot be used for the switchover (M1 to M5, M17, M30, M40 to M45) Control reaction: Mode group not ready. Channel not ready. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm.
Root Cause Summary
Alarm 4160 is triggered when machine data $MC_SPIND_RIGID_TAPPING_M_NR is configured with an M function number that is reserved by the SINUMERIK system for standard machine control operations. The NCK firmware prevents assignment of system-reserved M codes (M1, M5, M17, M30, M40-M45) to spindle switchover functions to avoid conflicts with modal group logic and safety-critical functions.
Safety
- Spindle hazard: ensure the spindle is at standstill before working near it; follow lockout/tagout procedures.
Causes and Fixes
- 1
Access the machine data editor via HMI menu: Maintenance > Machine Data > $MC_SPIND_RIGID_TAPPING_M_NR (or equivalent NCK/PLC parameter access path for your OEM panel).
Ensure machine is in IDLE state and no program is active before editing machine data.
- 2
Review the current value assigned to $MC_SPIND_RIGID_TAPPING_M_NR. Verify it is NOT M1, M5, M17, M30, M40, M41, M42, M43, M44, or M45.
- 3
If a reserved M code is found, change the parameter to an available M function (e.g., M6, M7, M8, M9, M10-M16, M18-M29, M46-M99) that is not used elsewhere in your machine data configuration.
- 4
Save machine data and perform a cold restart (power cycle or Ctrl+Shift+F9) to reload NCK parameters. Verify alarm clears and spindle switchover function operates correctly.
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