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Beckhoff Error Code Reference

Beckhoff TwinCAT & EtherCAT error code reference with causes and solutions

45 results

About Beckhoff Error Code Reference

The Beckhoff Error Code Reference is a searchable troubleshooting database covering 40+ error codes across five Beckhoff automation subsystems. It includes TwinCAT 3 runtime errors (0x4650 ERR_TC_TIMEOUT through 0x4658 ERR_TC_INVALIDSTATE), EtherCAT fieldbus errors (SYNC_ERROR, SYNC_MANAGER, FMMU_ERROR, STATE_MACHINE_ERROR, BOOTSTRAP_ERROR), and ADS communication faults (ERR_ADSTIMEOUT, ERR_SYMBOLNOTFOUND, ERR_NOADS, ERR_DEVICEBUSY).

The motion control section covers servo axis errors from MC_AXISINFAULT (0x4260) through MC_DRIVEERROR (0x4268), including encoder feedback failures, following errors, velocity/acceleration/torque limit violations, and hardware limit switch activations. The I/O terminal section addresses common field device diagnostics including wire break detection, over/under range signals, short circuits, overtemperature, overcurrent, and power supply faults.

Each error entry provides the hex code, symbolic name, detailed root cause analysis, and 4-step resolution guidance. Designed for PLC programmers, commissioning engineers, and maintenance technicians working with Beckhoff TwinCAT and EtherCAT systems.

Key Features

  • TwinCAT 3 runtime errors (0x4650-0x4658): timeout, uninitialized module, invalid parameter, memory, duplicate name, and state errors
  • EtherCAT fieldbus diagnostics: distributed clock sync, Sync Manager watchdog, FMMU configuration, PDO mapping, state machine transition, and bootstrap errors
  • ADS communication fault codes: internal error, port not installed, router not started, timeout, invalid parameters, symbol not found, device full, and device busy
  • Motion control axis errors: fault state reset, encoder feedback, following error, velocity/acceleration/torque limits, software and hardware limit switches, and drive hardware faults
  • I/O terminal diagnostics: not ready, configuration mismatch, wire break, over/under range, short circuit, overtemperature, overcurrent, and supply voltage faults
  • Each error includes hex code, symbolic name, root cause analysis, and step-by-step resolution
  • Organized by subsystem (TwinCAT Runtime, EtherCAT, ADS, Motion, I/O) for quick lookup during commissioning
  • Searchable by hex code, symbolic name, or keyword with instant filtering

Frequently Asked Questions

What does TwinCAT error 0x4650 (ERR_TC_TIMEOUT) mean and how do I fix it?

Error 0x4650 indicates the PLC program execution exceeded the configured task cycle time, causing an overrun. Fix it by increasing the task cycle time in TwinCAT System Manager, optimizing PLC program logic to remove unnecessary computations, moving heavy processing to a slower task, or checking CPU core assignment in the Real-Time tab.

How do I resolve EtherCAT state machine error 0x0033?

State machine error 0x0033 means a slave cannot complete its state transition (INIT to PREOP to SAFEOP to OP). Check the slave AL Status Code in TwinCAT System Manager for the specific cause, verify PDO mapping and Sync Manager configuration, ensure the slave firmware version matches the ESI file, and inspect physical wiring including the 120-ohm termination resistor.

What causes ADS timeout error 0x0007 (ERR_ADSTIMEOUT)?

ADS timeout occurs when no response is received within the configured timeout period. Common causes include network connectivity issues, incorrect AmsNetId or port number, target system overload, or the PLC not being in RUN mode. Verify network connection, check AmsNetId format (x.x.x.x.x.x), adjust timeout values, and confirm the target PLC is running.

How do I troubleshoot MC_POSITIONLAG (0x4262) following error on a servo axis?

Following error means the actual position deviates from the commanded position beyond tolerance. Check and potentially increase the Following Error Window setting, tune servo gains (Kv, Kp, Ki) for tighter control, inspect for mechanical issues like excessive load or friction, and reduce acceleration/velocity profiles to gentler ramp values.

What does I/O terminal error 0xF102 (IO_WIREBREAK) indicate?

IO_WIREBREAK indicates an open circuit detected on an analog input, such as a disconnected sensor wire, an open 4-20mA current loop, or a broken thermocouple/RTD connection. Inspect physical wiring, use a multimeter to verify circuit continuity, confirm the sensor is connected to the correct terminal, and test the sensor itself for failure.

How do I fix EtherCAT distributed clock sync error 0x001A?

Sync error 0x001A means the distributed clock synchronization between slaves has drifted beyond tolerance. Inspect EtherCAT cable connections and cable quality, adjust the Sync Shift Time in the DC settings, check DC diagnostic information in TwinCAT System Manager, and verify that the slave firmware supports Distributed Clocks.

What should I check when I get ADS symbol not found error 0x0274?

Error 0x0274 (ERR_SYMBOLNOTFOUND) means the requested variable name does not exist in the PLC program. Double-check symbol name spelling and case sensitivity, verify the PLC program has been downloaded with the latest version, ensure the variable is declared in the correct scope (MAIN, GVL, etc.), and regenerate the TMC file to refresh the symbol list.

Is this Beckhoff error code reference free and does it work offline?

Yes, this reference is completely free with no account, download, or usage limits. All content loads in your browser and works without sending data to any server. Once the page has loaded, all searching and filtering works entirely client-side, making it suitable for use in industrial environments with limited connectivity.