EL
ErrorLib
Brands
||
  1. Home
  2. Beckhoff
  3. TwinCAT 2 NC
  4. 4501
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

4501

Controller type not allowed

Beckhoff · TwinCAT 2 NC

What does 4501 mean?

The value specified for the controller type is unacceptable because it is not a defined type within the system (e.g., Types 1-8 are defined, but Type 9 is not). An incorrect controller type prevents the NC from applying the appropriate control algorithms and parameters, leading to misbehavior or non-operation of the controlled axis/system.

Common Causes

  • The configured controller type parameter (e.g., P3-02, Controller Type) is set to an undefined value (e.g., '9') not supported by the system.
  • Mismatch between the actual physical controller hardware and the selected controller type in the configuration parameters.
  • Outdated firmware on the master controller or drive that does not recognize the specified controller type.
  • Corruption of the configuration memory causing the controller type parameter to default to an invalid value.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    1. Verify the configured controller type parameter (e.g., P3-02) matches one of the defined valid types listed in the system manual (e.g., 1-8).

  2. 2

    2. Consult the system's technical documentation to determine the correct numerical value for the controller type corresponding to the installed hardware.

  3. 3

    3. Ensure the drive or controller firmware is up-to-date and supports the intended controller type configuration.

  4. 4

    4. Re-enter the controller type parameter (P3-02) using the configuration software to ensure correct data integrity.

  5. 5

    5. Perform a full parameter download and power cycle of the controller after making changes to ensure the new type is recognized.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

4000Internal error4001Memory error4002Nc retain data error (persistent data)
Source: Beckhoff TwinCAT 2 NC
View Official PDFSearch more codes in this manual