Schneider Lexium LXM23 Plus Drive Fault Codes

Complete reference list of Schneider Lexium 23 Plus (LXM23A/LXM23D) servo drive fault codes. Learn to troubleshoot AL codes like AL006 (Overload), AL009 (Position Error), and AL011 (Encoder).

Schneider LXM23 Plus Fault Codes Reference Table

Schneider LXM23 Plus Fault Codes Reference Table

Fault Code and Meaning	Cause and Remedy
AL401 CAN bus error	Cause: NMT reset or NMT stop command is received when the servo drive is enabled. Remedy: Refer to the CANopen fieldbus manual for additional information on CANopen objects.
AL001 Overcurrent	Cause: Short-circuit at drive output (U, V, W). Remedy: Remove the short circuit and keep conductors from being exposed. Cause: Motor wiring error. Remedy: Follow the wiring steps in the product manual to reconnect wiring. Cause: IGBT error (Heat sink overheated). Remedy: Contact Schneider Electric support. Cause: Control parameter setting error. Remedy: Set the setting back to factory default setting and then reset and adjust the parameter setting again. Cause: Control command setting error (Input unstable). Remedy: Verify that input command frequency is stable. Activate filter function.
AL002 Overvoltage	Cause: The main circuit voltage has exceeded the maximum permissible value. Remedy: Use correct power supply or stabilizing power or use series transformer. Cause: Input power error (Incorrect power input). Remedy: Use correct power supply or stabilizing power or use series transformer. Cause: The hardware of the servo drive is damaged. Remedy: If the error persists even if the main circuit input voltage is in the specified limit, contact Schneider Electric support.
AL003 Undervoltage	Cause: The main circuit voltage is below the minimum specified value. Remedy: Reconfirm voltage wiring. Cause: No input voltage at main circuit. Remedy: Reconfirm power switch. Cause: Input power error (Incorrect power input). Remedy: Use correct power supply or stabilizing power or use series transformer.
AL004 Motor error	Cause: Encoder is damaged. Remedy: Replace the motor. Cause: Encoder is loose. Remedy: Install the motor again. Cause: The type of the servo motor is incorrect (size/power rating mismatch). Remedy: Replace the motor.
AL005 Braking resistor error	Cause: Braking resistor is not connected or the value is too low. Remedy: Reconnect braking resistor or calculate the value of the braking resistor. Cause: Braking resistor switch transistor error. Remedy: Contact Schneider Electric support. Cause: Parameter setting error. Remedy: Correctly reset parameter settings (P1-52, P1-53) and the specifications of braking resistor again.
AL006 Overload	Cause: The drive has exceeded the rated load during continuous operation. Remedy: Increase motor capacity or reduce load. Cause: Control system parameter setting is incorrect (Vibration or Accel/Decel too fast). Remedy: Adjust gain value of control circuit. Decrease Accel/Decel time setting. Cause: The wiring of drive and encoder is incorrect. Remedy: Verify that the wiring is correct. Cause: The encoder of the motor is damaged. Remedy: Contact Schneider Electric support.
AL007 Overspeed	Cause: Speed input command is not stable (too much fluctuation). Remedy: Verify that the input command frequency is stable and activate filter function. Cause: Over-speed parameter setting is incorrect (too low). Remedy: Correctly set over-speed parameter setting (P2-34).
AL008 Abnormal pulse control command	Cause: Pulse command frequency is higher than rated input frequency. Remedy: Correctly set the input pulse frequency.
AL009 Excessive deviation	Cause: Maximum deviation parameter setting is too small. Remedy: Increase the parameter setting value of P2-35. Cause: Gain value is too small. Remedy: Correctly adjust gain value. Cause: Torque limit is too low. Remedy: Correctly adjust torque limit value. Cause: There is an overload. Remedy: Reduce external applied load or reestimate the motor capacity.
AL011 Encoder error (Position detector error)	Cause: The wiring of the encoder is incorrect. Remedy: Verify that the wiring is correct. Cause: Encoder is loose. Remedy: Install the motor again. Cause: The wiring of encoder is incorrect (loose connections). Remedy: Re-wire. Cause: Encoder is damaged. Remedy: Replace the motor.
AL012 Adjustment error	Cause: The analog input contact does not go back to zero. Remedy: Correctly ground the analog input contact. Cause: The detection device is damaged. Remedy: Reset the power supply. If error persists, contact Schneider Electric support.
AL013 Operational stop activated	Cause: Operational stop switch is activated. Remedy: Activate operational stop switch (Check On/Off status).
AL014 Reverse (CWL) limit switch error	Cause: Reverse limit switch is activated. Remedy: Activate reverse limit switch. Cause: Servo system is not stable. Remedy: Modify parameter setting and reestimate motor capacity.
AL015 Forward (CCWL) limit switch error	Cause: Forward limit switch is activated. Remedy: Activate forward limit switch. Cause: Servo system is not stable. Remedy: Modify parameter setting and reestimate motor capacity.
AL016 IGBT temperature error	Cause: The drive has exceeded the rated load during continuous operation. Remedy: Increase motor capacity or reduce load. Cause: Short-circuit at drive output. Remedy: Verify that the wiring is correct.
AL017 Memory error	Cause: Parameter data error when writing into EEPROM. Remedy: If occurring at power on: Correct the setting value (P2-10 or P6-16) to clear alarm. If occurring during operation: Turn ARST (DI signal) ON to clear alarm or restart drive. Cause: The setting value of hidden parameter is in error (E100X). Remedy: Correctly set the servo drive type again. Cause: Data in EEPROM is damaged (E0001). Remedy: Contact Schneider Electric support.
AL018 Encoder output error	Cause: Encoder inoperative or encoder wiring error. Remedy: Perform the corrective actions as described in AL011, AL024, AL025, and AL026. Cause: The output frequency for pulse output may exceed the limit. Remedy: Correctly set P1-76 and P1-46. Verify motor speed is below value set by P1-76.
AL020 Serial communication timeout	Cause: Setting value in timeout parameter is not correct. Remedy: Correctly set P3-07. Cause: Not receiving communication command for a long time (cable loose/broken). Remedy: Tighten the communication cable, verify it is not damaged, and verify wiring is correct.
AL022 Input power phase missing	Cause: Control power supply error (Cable loose or input power phase missing). Remedy: If the alarm persists even when the three-phase power is connected correctly, contact Schneider Electric support.
AL023 Pre-overload warning	Cause: The drive is going to overload (Load condition or P1-56 setting too small). Remedy: See the corrective actions for AL006. Increase the setting value of P1-56 or set P1-56 to 100 and above.
AL024 Encoder initial magnetic field error	Cause: The magnetic field of the encoder U, V, W signal is incorrect. Remedy: If the error persists after checking grounding and shielding, contact Schneider Electric support.
AL025 Encoder internal error	Cause: The internal memory of the encoder is inoperative. An encoder counter error occurs. Remedy: Connect grounding correctly. Verify encoder signal cables are in separate conduits. Use shielded cables. If error persists, contact Schneider Electric support.
AL026 Encoder data error	Cause: An encoder data error occurs for three times. Remedy: Connect grounding correctly. Verify encoder signal cables are in separate conduits. Use shielded cables. If error persists, contact Schneider Electric support.
AL027 Encoder reset error	Cause: An encoder reset error has been detected. Communication error between encoder and drive. Remedy: Connect grounding correctly. Verify encoder signal cables are in separate conduits. Use shielded cables. If error persists, contact Schneider Electric support.
AL030 Motor monitoring error	Cause: The setting value of parameter P1-57 is reached after a period of time set by parameter P1-58. Remedy: Set P1-57 to 0. Correctly set P1-57 and P1-58 (Excessively low settings cause errors).
AL031 U,V,W wiring error	Cause: Incorrect wiring connections of U, V, W (for servo motor output) and ground. Remedy: Follow the wiring steps in the product manual to reconnect the wiring and ground the servo drive and motor properly.
AL099 DSP firmware upgrade	Cause: EEPROM is not reset after the firmware version is upgraded. Remedy: Set P2-08 to 30 first, and then 28 next, and restart the servo drive.
AL111 CANopen SDO receive buffer overrun	Cause: SDO Rx buffer overrun is detected (receive two or more SDO packets in 1ms). Remedy: NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL112 CANopen PDO receive buffer overrun	Cause: PDO Rx buffer overrun is detected (receive two or more PDO packets in 1ms). Remedy: NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL121 Index error occurs when accessing PDO object	Cause: The specified Index in the message does not exist. Remedy: NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL122 Sub-index error occurs when accessing PDO object	Cause: The specified Sub-index in the message does not exist. Remedy: NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL123 Data type (size) error occurs when accessing PDO object	Cause: The data length in the message does not match the specified object. Remedy: NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL124 Data range error occurs when accessing PDO object	Cause: The data in the message has exceeded the data range of the specified object. Remedy: Check if the write-in data range in PDO mapping is not correct when accessing PDO object. NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication (the value of CANopen object 0x6040 should be reset).
AL125 Object is read-only and write-protected	Cause: The specified object in the message is read-only and write-protected (cannot be changed). Remedy: Check if the specified object is set to read-only write-protected when accessing PDO object. NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL126 CANopen PDO object does not support PDO	Cause: The specified object in the message cannot support PDO. Remedy: Check if the specified object cannot support PDO when accessing PDO object. NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL127 CANopen PDO object is write-protected when Servo On	Cause: The specified object in the message is write-protected (cannot be changed) when Servo On. Remedy: Check if the specified object in the message is write-protected while the servo drive is enabled (Servo On) when accessing PDO object. NMT Master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL128 Error occurs when reading CANopen PDO object from EEPROM	Cause: An error occurs when loading the default settings from EEPROM at start-up. The CANopen objects return to their default settings automatically. Remedy: Check if it causes an error when the specified object reads EEPROM when accessing PDO object. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL129 Error occurs when writing CANopen PDO object into EEPROM	Cause: An error occurs when writing the current settings into EEPROM. Remedy: Check if it causes an error when the specified object writes EEPROM when accessing PDO object. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL130 EEPROM invalid address range	Cause: The amount of the data saved in EEPROM has exceeded the space determined by the firmware. Maybe the firmware version has been upgraded, and it causes that the data of old firmware version saved in EEPROM cannot be used. Remedy: Check if the specified object lets the address range of EEPROM exceed the specification when accessing PDO object. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL131 EEPROM checksum error	Cause: The data saved in EEPROM has been damaged and the CANopen objects return to their default settings automatically. Remedy: Check if the specified object results in the checksum error of EEPROM when accessing PDO object. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL132 Password error	Cause: The parameter is password protected when using CANopen communication to access the parameter. Remedy: Check if the password for the specified object is invalid when accessing PDO object. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL180 Life guard error or heartbeat error	Cause: Receive node guarding or heartbeat message has timed out. Remedy: Check the settings of node guarding or heartbeat function. NMT master sends "Reset node" command to the slave.
AL185 CANbus error	Cause: CANbus off or Error Rx/Tx Counter exceeds 128. Remedy: Check CANbus communication cable. Check if the communication quality is good (It is recommended to use shielded cables and use common grounding). NMT master sends "Reset node" command to the slave or restart the servo drive.
AL201 CANopen data initial error	Cause: An error occurs when loading data from EEPROM. Remedy: Restart the servo drive to check if the error can be cleared (Turn ARST DI signal ON). If the error cannot be cleared after restarting the servo drive, it indicates that the data in EEPROM is damaged. Use CANopen "0x1011" object to restore default parameters: If you want to write default setting values, set P2-08 to 30 first and then 28 next, or use CANopen "0x1011" object to restore parameters from non-volatile memory. If you want to write current setting values, use CANopen "0x1010" object to save parameters in non-volatile memory.
AL235 Command overflow	Cause: This alarm occurs when position command counter register overflowed and at this time an absolute position command is executed. Remedy: Check if the position command is executing continuously toward single direction causing the feedback position command counter overflow. Check if the above situation causes that the correct position cannot be gauged. Check if an absolute position command is executed after the position command counter register overflowed. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL261 Index error occurs when accessing CANopen object	Cause: The specified Index in the message does not exist. Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL263 Sub-index error occurs when accessing CANopen object	Cause: The specified Sub-index in the message does not exist. Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL265 Data type (size) error occurs when accessing CANopen object	Cause: The data length in the message does not match the specified object. Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL267 Data range error occurs when accessing CANopen object	Cause: The data in the message has exceeded the data range of the specified object. Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL269 Object is read-only and write-protected	Cause: The specified object in the message is read-only and write-protected (cannot be changed). Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL26b CANopen object does not support PDO	Cause: The specified object in the message does not support PDO. Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL26d Object is write-protected when Servo On	Cause: The specified object in the message is write-protected (cannot be changed) when Servo On. Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL277 Password error	Cause: The parameter is password protected when using CANopen communication to access the parameter. Remedy: Verify that the correct data is used. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL283 Forward software limit	Cause: Position command is equal to or more than forward software limit. Remedy: This software limit is determined according to position command, not actual feedback position. The actual position may not exceed the limit. Set the proper deceleration time (See parameter P5-03) to solve this problem. When the servo drive does not reach the limit (i.e., position command is less than forward software limit), this alarm removes automatically.
AL285 Reverse software limit	Cause: Position command is equal to or less than reverse software limit. Remedy: This software limit is determined according to position command, not actual feedback position. The actual position may not exceed the limit. Set the proper deceleration time (See parameter P5-03) to solve this problem. When the servo drive does not reach the limit (i.e., position command is less than reverse software limit), this alarm removes automatically.
AL3E1 CANopen SYNC error	Cause: CAN IP mode error. No synchronous communication with the external master. Remedy: Check if the communication quality is good. Check if the (external) master has sent SYNC signal. Check if the setting value of parameter P3-09 is a proper value (It is recommended to use default setting). NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL3E2 CANopen SYNC error	Cause: CAN IP mode error. The SYNC signal is received too early. Remedy: Check if the setting of 0x1006 (communication cycle period) is the same as the setting in the (external) master. Check if the setting value of parameter P3-09 is a proper value (It is recommended to use default setting). Check if the procedure of (external) master is not correct. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL3E3 CANopen SYNC timeout	Cause: CAN IP mode error. The SYNC signal is not received with the specified time. Remedy: Check if the communication quality is good. Check if the setting of 0x1006 (communication cycle period) is the same as the setting in (external) master. Check if the setting value of parameter P3-09 is a proper value (Recommended default). Check if the procedure of (external) master is not correct. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040).
AL3E4 CANopen IP command error	Cause: CAN IP mode error. Internal command cannot be sent and received. The calculation time of IP mode is too long. Remedy: NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL3E5 SYNC period error	Cause: Object 0x1006 Data Error. SYNC period 1006h value is invalid. Remedy: Check the data of 0x1006. The SYNC period 1006h value should not be equal to or less than 0. NMT master sends "Reset node" command to the slave or reset the alarm by sending the control word (0x6040) through CAN communication.
AL380 Position deviation alarm for digital output, MC_OK	Cause: After MC_OK is activated, when the digital output, TPOS is Off, the digital output, MC_OK becomes Off. Remedy: Check if the motor position changes by external force after the positioning is completed. This alarm can be disabled by the setting of P1-48. Turn ARST (DI signal) ON to clear the alarm. Set P0-01 to 0.
AL401 CANopen state error	Cause: NMT reset or NMT stop command is received when the servo drive is enabled. Remedy: Check if NMT reset or NMT stop command is sent when drive is enabled. Reset the alarm by sending the control word (0x6040) through CAN communication. Reset the alarm by triggering FR of driveCtrl of dmControl (control data of PLCopen Profile).

 

How to Read LXM23 Plus Servo Faults

The LXM23 Plus diagnostics are straightforward. Understanding the difference between a “Major” fault and a “Minor” alarm is key to troubleshooting.

• AL Codes (Alarms): The display alternates between “AL” and the code number.
  • AL001 – AL005: Power Section faults (IGBT, Overcurrent, Overvoltage). These usually require a power cycle to reset.
  • AL013 – AL015: Limit Switch triggers (Reverse/Forward Limits). These are safety stops indicating the machine has hit its physical travel end.
• Digital Inputs (ALRS): Many faults (like AL009 Position Deviation) can be cleared without powering down by triggering the Digital Input assigned to Alarm Reset (ALRS).
• Lexium 23 CT Software: For detailed analysis, connect the drive to a PC via the CN3 port (Mini-USB). The software’s oscilloscope can capture the speed and current waveforms leading up to the fault.

Frequently Asked Questions (FAQ)

Q: What does “AL011” (Encoder Error) mean?

A: The drive has lost communication with the motor encoder.
Common Causes:
1. Loose Connection: The encoder cable (CN2 port) is loose or vibrating.
2. Cable Break: If the motor moves in a drag chain, the internal wires may have snapped.
3. Noise: High voltage interference on the encoder line. Ensure the shield is grounded.

Q: How do I fix “AL009” (Position Deviation Too Large)?

A: This occurs in Pulse Train (PT) mode when the motor cannot keep up with the controller’s command.
Fix:
1. Mechanical: Check for a jammed axis or excessive friction.
2. Tuning: The servo gains are too low (“Soft”). Increase the Position Loop Gain (P2-00) to make the motor more responsive.
3. Max Speed: Ensure the command frequency doesn’t demand a speed higher than the motor’s rated limit.

Q: Why do I see “AL013” or “AL014”?

A: These are Limit Switch alarms.
AL013: Reverse Limit Switch (N-OT) triggered.
AL014: Forward Limit Switch (P-OT) triggered.
Action: Use the keypad or manual handwheel to move the load away from the limit switch. If no switch is installed, check that the Digital Input parameters (P2-10 to P2-17) are set to “Normally Open” or disabled (Code 0).