Siemens SINUMERIK codes
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Siemens SINUMERIK Controller

Program/G-code · Intermediate · 30-120 minutes

Alarm 100850

Siemens 840D 100850 - Note : PCU 20 memory limit exceeded

Alarm 100850 indicates that the PCU 20 (Panel Control Unit) has exceeded its available memory resources during program execution or data processing. This is typically caused by excessive NC program size, too many loaded programs in memory, or accumulated HMI/PLC data that has not been properly cleared.

Siemens SINUMERIKProgram/G-codeIntermediate30-120 minutes

100850

Siemens 840D 100850 - Note : PCU 20 memory limit exceeded

Note : PCU 20 memory limit exceeded

Siemens SINUMERIK operator message 100850: Note: PCU 20 memory limit exceeded. This is an informational message from the SINUMERIK control indicating a system status or operation result that may require operator action.

Root Cause Summary

Alarm 100850 indicates that the PCU 20 (Panel Control Unit) has exceeded its available memory resources during program execution or data processing. This is typically caused by excessive NC program size, too many loaded programs in memory, or accumulated HMI/PLC data that has not been properly cleared.

Safety

  • Refer to Siemens documentation
  • Ensure qualified technician performs repairs

Causes and Fixes

  1. 1

    Access HMI and navigate to Program Manager to view all loaded NC programs in memory.

  2. 2

    Delete or unload unused NC programs and subroutines from active memory using 'Delete' function.

    Ensure programs are backed up to CF card or network location before deletion

  3. 3

    Check individual program file sizes - reduce programs exceeding 5MB by splitting into smaller subroutines.

  4. 4

    Perform NCK reset (power cycle control) and reload only required programs for current operation.

    Coordinate with production to minimize downtime during reset

Service Recommended confidence

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