Siemens SINUMERIK codes
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Siemens SINUMERIK Controller

Spindle · Intermediate · 30-120 minutes

Alarm 16672

Siemens 16672 - Block leading axis/spindle maximum number of CP master

Alarm 16672 occurs when an NC program attempts to activate more master values (couplings) for a leading axis or spindle than the system has allocated in MD18452 (Maximum number of generic couplings). This exceeds the configured CP (Coupling Point) limit for the specified channel and spindle combination.

Siemens SINUMERIKSpindleIntermediate30-120 minutes

16672

Siemens 16672 - Block leading axis/spindle maximum number of CP master

Block leading axis/spindle maximum number of CP master

An attempt was made to activate more master values of generic couplings than are configured in MD18452 $MN_MM_NUM_CP_MODUL_LEAD Control reaction: Correction block is reorganized. Interface signals are set. Alarm display.

Root Cause Summary

Alarm 16672 occurs when an NC program attempts to activate more master values (couplings) for a leading axis or spindle than the system has allocated in MD18452 (Maximum number of generic couplings). This exceeds the configured CP (Coupling Point) limit for the specified channel and spindle combination.

Safety

  • Spindle hazard: ensure the spindle is at standstill before working near it; follow lockout/tagout procedures.

Causes and Fixes

  1. 1

    Navigate to Diagnostics > Machine Data > MD18452 in the HMI to verify the current maximum CP allocation for the affected channel.

  2. 2

    Review the active NC program block (%2) and count the total number of COUPLE/COUPLE_SPIND instructions targeting the leading axis/spindle (%3).

  3. 3

    If required couplings exceed MD18452 value, increase MD18452 to the necessary count (typically 4-16 depending on machine architecture) and perform a warm restart (NCK reset).

    Increasing MD18452 may impact NCK cycle time and memory allocation. Consult the machine builder's commissioning documentation for recommended limits.

  4. 4

    Verify the change took effect by checking Diagnostics > Machine Data > MD18452 post-restart, then rerun the NC program.

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