Siemens SINUMERIK codes
AxisMD

axismd.ai

Siemens SINUMERIK Controller

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

Alarm 4021

Siemens 4021 - Identifier used several times in machine data

This alarm occurs when an identifier is used multiple times in channel-specific machine data, causing a conflict. Fix it by ensuring unique identifiers in the affected machine data settings.

Siemens SINUMERIKProgram/G-codeIntermediate30-120 minutes

4021

Siemens 4021 - Identifier used several times in machine data

Identifier used several times in machine data

To determine the name in the channel-specific tables for geometry axes and channel axes an identifier already existing in the control has been used Control reaction: NC not ready. Mode group not ready, also effective for single axes. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm.

Root Cause Summary

This alarm occurs when an identifier is used multiple times in channel-specific machine data, causing a conflict. Fix it by ensuring unique identifiers in the affected machine data settings.

Safety

  • Only qualified personnel should diagnose and clear control alarms; follow the machine builder's safety procedures and lockout/tagout where hardware work is required.

Causes and Fixes

  1. 1

    Check alarm details

    Note the channel and identifier mentioned in the alarm message.

  2. 2

    Review machine data

    Access the machine data settings for the specified channel and locate the duplicate identifier in %3.

  3. 3

    Assign unique identifier

    Modify the duplicate identifier to a unique value and save the changes.

  4. 4

    Reset and test

    Clear the alarm and test the program to confirm the issue is resolved.

DIY Feasiblehigh confidence

Call a technician if:

  • ·If unable to locate or modify the duplicate identifier
  • ·If alarm persists after changing machine data

Prevention

  • Always use unique identifiers for channel-specific data
  • Document machine data changes during setup or updates
  • Only allow qualified personnel to modify machine data
  • Always backup machine data before making changes

Common Mistakes

  • Overlooking the specific channel or identifier in the alarm
  • Failing to save changes after modifying machine data

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.