Siemens SINUMERIK codes
AxisMD

axismd.ai

Siemens SINUMERIK Controller

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

Alarm 101620

Siemens 840D 101620 - Device buffer too small to answer the job.

Alarm 101620 indicates that the communication buffer allocated for device data exchange is insufficient to handle the requested operation. This typically occurs when complex synchronous actions, large data blocks, or multiple simultaneous operations exceed the available buffer memory in the NCK or PLC communication interface.

Siemens SINUMERIKProgram/G-codeIntermediate30-120 minutes

101620

Siemens 840D 101620 - Device buffer too small to answer the job.

Device buffer too small to answer the job.

Siemens SINUMERIK operator message 101620: Device buffer too small to answer the job. 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 101620 indicates that the communication buffer allocated for device data exchange is insufficient to handle the requested operation. This typically occurs when complex synchronous actions, large data blocks, or multiple simultaneous operations exceed the available buffer memory in the NCK or PLC communication interface.

Safety

  • Refer to Siemens documentation
  • Ensure qualified technician performs repairs

Causes and Fixes

  1. 1

    Review the NC program at the point of alarm occurrence for synchronous action commands (AXACT, WAITP, WAITM) and check for excessive data transfers or multiple simultaneous sync operations.

  2. 2

    Reduce the data volume per synchronous action by splitting complex operations into smaller sequential blocks with intermediate wait states.

  3. 3

    Check machine data MD10280 (MAX_AX_PER_CHAN) and MD10290 (NUM_SYNC_AX) for excessive allocations that may consume buffer resources unnecessarily.

    Modifying these machine data settings requires a full NCK reset and re-referencing of all axes.

  4. 4

    Verify the NCK software version and consider updating to the latest patch level, as buffer management improvements have been implemented in newer releases.

Service Recommended confidence

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.