4011

Group identifier not allowed

Beckhoff · TwinCAT 2 NC

What does 4011 mean?

An unacceptable value (outside the range of 1 to 255) has been used for a group identifier, or the specified group does not exist within the current system configuration. This parameter error prevents proper identification and control of the specified group of axes, leading to failure of coordinated motion commands.

Common Causes

  • Invalid group number specified in the NC program or PLC command (outside 1-255).
  • Configuration parameter P3-05 ('Number of Groups') defining the total motion groups is incorrect.
  • Attempting to access a motion group that has not been defined or enabled in the NC configuration.
  • Typographical error in the NC program or HMI interface when referencing a specific motion group.
  • System configuration file corruption leading to incorrect group definitions or mappings.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    1. Inspect the NC program or PLC logic for any commands specifying a group identifier and correct it to a valid, configured group (e.g., Group 1 for XYZ motion).

  2. 2

    2. Verify the NC configuration parameter P3-05 ('Number of Motion Groups') reflects the actual number of configured groups.

  3. 3

    3. Check the group definitions in the NC setup (e.g., System Configuration menu > Groups) to confirm the existence of the specified group.

  4. 4

    4. Reload a known good NC configuration file from backup to restore proper group definitions.

  5. 5

    5. Ensure any HMI screens or external systems generating group commands use valid identifiers configured in the NC.

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Verified technical data. Last updated: March 2026

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