Mitsubishi MELSERVO MR-JE Servo Drive

Mitsubishi MELSERVO-JE Servo Drive Fault Codes:

Fault Code and Meaning	Cause and Remedy
10.1 Undervoltage: Voltage drop in the power	Cause: Connection of power connector has a failure. Power supply voltage is low (160V AC or less). Instantaneous power failure > 60ms. For 1-phase power, wiring is incorrect. Remedy: Check the power connector and connect it correctly. Review the power supply voltage. Check the power supply wiring (L1, L3 for MR-JE-100; L1, L2 for MR-JE-200).
10.2 Undervoltage: Bus voltage drop	Cause: Connection of power connector has a failure. Power supply voltage is low. Alarm occurred during acceleration. Servo amplifier is malfunctioning. Remedy: Connect the power connector correctly. Increase the power supply voltage. Increase acceleration time constant or power supply capacity. Replace the servo amplifier.
11.1 Switch setting error	Cause: Station number set to value other than “0” to “247” (Modbus RTU). Remedy: Set the station number correctly (SW1/SW2). If set correctly and error persists, replace the servo amplifier.
12.1 – 12.6 RAM error (1 to 6)	Cause: A part (RAM) in the servo amplifier has a failure. Noise affecting the device. Remedy: Disconnect cables (except power). If error is repeatable, replace the servo amplifier. Check power supply for noise and take countermeasures.
13.1 Clock error 1	Cause: Part in servo amplifier has failure. Clock transmitted from controller has failure. Servo amplifier of next axis is malfunctioning. Connector shorted or noise. Remedy: Disconnect cables; if repeatable, replace servo amplifier. If alarm occurs when connected to controller, replace controller. Check next axis; if malfunctioning, replace next axis amplifier. Check for shorts or noise in the surrounding environment.
14.1 Control process error 1	Cause: Parameter setting is incorrect. Connector shorted or noise. Servo amplifier is malfunctioning. Remedy: Check parameter settings and set correctly. Take countermeasures against noise/shorts. Replace the servo amplifier.
15.1 EEP-ROM error at power on	Cause: EEP-ROM malfunctioning at power on. Noise or shorted connector. Write times exceeded 100,000. Remedy: Disconnect cables; if repeatable, replace servo amplifier. Reduce frequency of parameter/point table changes after replacement.
15.2 EEP-ROM error during operation	Cause: Malfunction during normal operation or tuning. Noise or shorted connector. Remedy: If alarm occurs when changing parameters, replace servo amplifier. Take countermeasures against noise.
15.4 Home position information read error	Cause: EEP-ROM malfunction. Multiple rotation data lost. Noise. Remedy: Replace servo amplifier if repeatable. Perform home position setting again.
16.1 Encoder initial communication error 1	Cause: Encoder cable malfunctioning/shorted. Servo amplifier malfunctioning. Encoder malfunctioning. Noise/Vibration. Remedy: Replace or repair the encoder cable. Replace the servo amplifier. Replace the servo motor. Take countermeasures against noise/vibration.
16.3 Encoder initial communication error 3	Cause: Encoder cable disconnected. Parameter setting (2-wire/4-wire) incorrect. Power supply voltage unstable. Remedy: Connect encoder cable correctly. Set parameters [Pr. PC22] or [Pr. PC04] correctly. Review power supply and related parts.
17.1 Board error 1	Cause: Current detection circuit malfunctioning. Noise in surrounding area. Remedy: Replace the servo amplifier. Take countermeasures against noise.
17.4 Board error 3	Cause: Servo amplifier recognition signal not read properly. Noise. Remedy: Disconnect cables (except power). If repeatable, replace servo amplifier.
19.1 – 19.5 Memory error 3 (Flash-ROM)	Cause: The Flash-ROM is malfunctioning. Noise affecting the device. Remedy: Disconnect cables (except power). If repeatable, replace servo amplifier. Take countermeasures against noise.
1A.1 Servo motor combination error	Cause: Servo amplifier and motor connected incorrectly. Encoder is malfunctioning. Remedy: Use the correct combination of servo amplifier and motor. Replace the servo motor.
1A.4 Servo motor combination error 2	Cause: The servo amplifier is malfunctioning. Remedy: Replace the servo amplifier.
1E.1 Encoder initial communication error 2	Cause: Encoder is malfunctioning. Noise/Vibration. Remedy: Replace the servo motor. Take countermeasures against noise/vibration.
1F.1 Incompatible encoder	Cause: Incompatible servo motor connected. Software version of amplifier not compatible with motor. Encoder malfunctioning. Remedy: Replace with a compatible servo motor. Replace servo amplifier with compatible software version. Replace the servo motor.
20.1 Encoder normal communication error 1	Cause: Encoder cable disconnected or shorted. Encoder cable shield not connected to ground plate. Servo amplifier or Encoder malfunctioning. Remedy: Repair or replace the cable. Connect cable shield to connector ground plate correctly. Replace servo amplifier or servo motor.
21.1 Encoder data error 1	Cause: High speed/acceleration due to oscillation. Encoder cable shield not connected to ground. Encoder malfunctioning. Remedy: Use the encoder with low loop gain. Connect ground correctly. Replace the servo motor.
24.1 Main circuit error: Ground fault	Cause: Servo amplifier malfunctioning. Ground fault or short in servo motor power cable. Insulation failure in motor (U/V/W). Power input cable and motor power cable are shorted. Remedy: Replace the servo amplifier. Replace the servo motor power cable. Correct the wiring or replace the motor.
25.1 Servo motor encoder – Absolute position erased	Cause: Absolute position data is faulty. Common causes include: first time power-on, battery replacement, disconnected battery cable during power-off, low battery voltage (< 3V), or cable/encoder malfunction. Remedy: Check if this is the first power-on; perform a home position return. Ensure battery is mounted correctly. If battery voltage is less than 3V, replace the battery. Check for loose connections in the battery or encoder cables. Use recommended wires for encoder cables to prevent voltage drop. If the servo amplifier is malfunctioning, replace it. If the encoder is malfunctioning, replace the servo motor.
30.1 Regeneration heat error	Cause: Regenerative resistor/option setting is incorrect ([Pr. PA02]), not connected, or the regenerative load ratio exceeded 100% (power supply high). Remedy: Set the regenerative resistor/option parameters correctly. Connect the regenerative resistor correctly. Use the correct combination of servo amplifier and regenerative option. If power supply is over 264 V AC, reduce the voltage. Reduce frequency of positioning or increase deceleration time constant. Review regenerative option capacity.
30.2 Regeneration signal error	Cause: A detection circuit of the servo amplifier is malfunctioning (overheating). Remedy: Replace the servo amplifier.
30.3 Regeneration feedback signal error	Cause: Detection circuit malfunction or external noise/ground fault. Remedy: Remove regenerative option and check if alarm persists. If yes, replace servo amplifier. Check for noise, ground faults, or ambient temperature issues in the surrounding environment.
31.1 Abnormal motor speed (Overspeed)	Cause: Motor speed exceeded permissible limit. Causes include: high command pulse frequency, incorrect electronic gear setting, unstable system, or overshooting velocity waveform. Remedy: Check and adjust command pulse frequency. Review electronic gear settings. Check operation pattern if command from controller is excessive. Review [Pr. PC08] Overspeed alarm detection level. Increase acceleration/deceleration time constant. Adjust servo gain if system is oscillating. Check U/V/W wiring. Replace servo motor if encoder is malfunctioning.
32.1 Overcurrent detected at hardware detection circuit	Cause: Current higher than permissible applied. Causes: Amp malfunction, ground fault/short in motor cable, dynamic brake malfunction, or noise. Remedy: Disconnect motor cables (U/V/W) to isolate; if alarm persists, replace servo amplifier. Check cables for shorts or ground faults; replace if necessary. Check motor insulation; replace motor if ground fault occurring. Wire encoder cable correctly. Take countermeasures against noise.
32.2 Overcurrent detected at software detection circuit	Cause: High servo gain (oscillation), Amp malfunction, short/ground fault, or noise. Remedy: Reduce speed control gain ([Pr. PB09]) if oscillation is occurring. Perform checks similar to fault 32.1 (cables, motor insulation, amplifier health).
32.3 / 32.4 Overcurrent detected (during stop)	Cause: Detected at hardware (32.3) or software (32.4) during a stop. Remedy: Refer to remedies for Fault 32.1 and 32.2.
33.1 Main circuit voltage error (Overvoltage)	Cause: Bus voltage exceeded 400 V DC. Causes: Regenerative setting error, wire breakage, insufficient regeneration capacity, or high power supply voltage. Remedy: Correct the regenerative resistor/option setting [Pr. PA02]. Check connections and wire continuity of the regenerative resistor. Replace servo amplifier if built-in resistor is broken. Use a larger capacity regenerative option if capacity is insufficient. Ensure input power supply is 264 V AC or less.
34.1 SSCNET receive data error	Cause: SSCNET III/H communication error (continuous). Cable disconnected, dirty tip, broken wire, or noise. Remedy: Turn off amplifier, reconnect SSCNET III cable. Wipe dirt from cable tip. Replace SSCNET III cable if broken. Separate cable from other power lines (do not use vinyl tape to bundle). Replace servo amplifier or controller if malfunctioning.
35.1 Command frequency error	Cause: Input command pulse frequency is too high, or filter setting [Pr. PA13] is incorrect. Remedy: Check operation pattern and reduce command pulse frequency. Correct the “Command input pulse train filter selection” setting. Reduce inputted frequency of manual pulse generator. Replace controller if malfunctioning.
36.1 SSCNET receive error 2	Cause: Intermittent communication error (approx 70ms interval). Cable disconnected, dirty, broken, or noise. Remedy: Securely connect SSCNET III cable. Clean cable optical tip. Replace SSCNET III cable. Check for noise interference. Replace servo amplifier or controller.
37.1 Parameter setting range error	Cause: A parameter was set out of range, or a setting contradicts another. Remedy: Set the parameter within the valid range. Correct the contradictory setting value. If error persists after reset, replace servo amplifier.
37.2 Parameter combination error	Cause: A parameter setting contradicts another. Remedy: Check parameter error number and correct the setting value.
37.3 Point table setting error	Cause: The setting of point tables is incorrect. Remedy: Check point table error number and correct the setting range. Replace servo amplifier if memory is malfunctioning.
39.1 Program error	Cause: Checksum mismatch at power-on (noise or write error). Remedy: Rewrite the program. Replace servo amplifier.
39.2 Instruction argument external error	Cause: Program never written, or command argument out of specifications. Remedy: Write the program. Correct the command description/arguments.
39.3 Register No. error	Cause: General purpose register number is out of specifications. Remedy: Correct the command description.
39.4 Non-correspondence command error	Cause: Used command is not supported. Remedy: Correct the command description.
3A.1 Inrush current suppression circuit error	Cause: Inrush current suppressor circuit is malfunctioning. Remedy: Replace the servo amplifier.
3E.1 Operation mode error	Cause: (1) An incompatible controller with SSCNET III/H was connected. (2) The controller was connected as SSCNET III. Remedy: Use a compatible controller. Change the SSCNET III setting to SSCNET III/H.
3E.6 Operation mode switch error	Cause: (1) Positioning mode in servo amplifier (point table/program) differs from actual positioning mode. Remedy: If changed with purpose: Initialize the point table method/program method. If changed by mistake: Set the positioning mode back to the correct setting.
45.1 Main circuit device overheat error	Cause: (1) Ambient temperature exceeded 55 ˚C. (2) Close mounting is out of specifications. (3) Repeated On/Off under overload status. (4) Cooling fan, heat sink, or openings clogged. (5) Servo amplifier malfunction. Remedy: Lower the ambient temperature. Use within range of specifications. Check operation pattern. Clean the cooling fan/heat sink/openings periodically. Replace the servo amplifier.
46.1 Abnormal temperature of servo motor 1	Cause: (1) Ambient temperature of servo motor exceeded 40 ˚C. (2) Servo motor is overloaded. (3) Thermal sensor in encoder is malfunctioning. Remedy: Lower the ambient temperature. Reduce load or review operation pattern. Replace the servo motor.
46.5 Abnormal temperature of servo motor 3	Cause: See Cause for 46.1. Remedy: Check it with the check method for [AL. 46.1].
46.6 Abnormal temperature of servo motor 4	Cause: (1) Current applied to servo amplifier in excess of continuous output current. Remedy: Reduce the load or review the operation pattern. Use a larger capacity motor.
47.2 Cooling fan speed reduction error	Cause: (1) Foreign matter caught in cooling fan. (2) Cooling fan reached end of life. Remedy: Remove the foreign matter. Replace the servo amplifier.
50.1 Thermal overload error 1 during operation	Cause: (1) Servo motor power cable disconnected. (2) Connection of servo motor (U/V/W) incorrect. (3) Electromagnetic brake not released. (4) Current exceeded continuous output current. (5) Encoder cable connection incorrect. (6) Servo system unstable/resonating. (7) Servo amplifier malfunctioning. (8) Encoder malfunctioning. Remedy: Repair or replace servo motor power cable. Connect wiring correctly. Release the electromagnetic brake. Reduce load or use larger capacity motor. Connect encoder cable correctly. Adjust gains. Replace the servo amplifier. Replace the servo motor.
50.2 Thermal overload error 2 during operation	Cause: See Cause for 50.1. Remedy: Check it with the check method for [AL. 50.1].
50.4 Thermal overload error 1 during a stop	Cause: (1) Moving part collided against machine. (2) Servo motor power cable disconnected. (3) Hunting occurs during servo-lock. (4) Electromagnetic brake not released. (5) Current exceeded continuous output current. (6) Encoder cable connection incorrect. (7) Servo system unstable/resonating. (8) Servo amplifier malfunctioning. (9) Encoder or servo motor malfunctioning. Remedy: Check operation pattern. Repair or replace servo motor power cable. Adjust gains. Release the electromagnetic brake. Reduce load or use larger capacity motor. Connect encoder cable correctly. Replace the servo amplifier. Replace the servo motor.
50.5 Thermal overload error 2 during a stop	Cause: See Cause for 50.4. Remedy: Check it with the check method for [AL. 50.4].
51.1 Thermal overload error 3 during operation	Cause: (1) Servo motor power cable disconnected. (2) Connection of servo motor (U/V/W) incorrect. (3) Connection of encoder cable incorrect. (4) Torque is insufficient. (5) Servo amplifier malfunctioning. (6) Encoder or servo motor malfunctioning. Remedy: Repair or replace servo motor power cable. Connect wiring correctly. Reduce load or review operation pattern. Use larger capacity motor. Replace the servo amplifier. Replace the servo motor.
51.2 Thermal overload error 3 during a stop	Cause: (1) A moving part collided against the machine. (2) Other causes (Refer to 51.1). Remedy: Check the operation pattern. Check it with the check method for [AL. 51.1].
52.1 Excess droop pulse 1	Cause: (1) Servo motor power cable disconnected. (2) Connection of servo motor incorrect. (3) Encoder cable connection incorrect. (4) Torque limit enabled. (5) Moving part collided with machine. (6) Electromagnetic brake not released. (7) Torque insufficient. (8) Power supply voltage dropped. (9) Acceleration/deceleration time too short. (10) Position loop gain is small. (11) Error excessive alarm level set incorrectly. (12) Shaft rotated by external force. (13) Servo-on enabled while motor rotating. (14) Encoder/Motor malfunction. (15) Amplifier malfunction. Remedy: Repair or replace power cable. Connect wiring correctly. Increase torque limit value. Check operation pattern. Release electromagnetic brake. Reduce load/review pattern or use larger motor. Check power supply voltage/capacity. Increase acceleration/deceleration time constant. Increase position loop gain ([Pr. PB08]). Set error excessive alarm level correctly ([Pr. PC24], [Pr. PC01]). Review machine/timing of servo-on. Replace servo motor. Replace servo amplifier.
52.3 Excess droop pulse 2	Cause: See Cause for 52.1. Remedy: Check it with the check method for [AL. 52.1].
52.4 Error excessive during 0 torque limit	Cause: (1) The torque limit value is 0. Remedy: Do not input a command while the torque limit value is 0.
52.5 Excess droop pulse 3	Cause: See Cause for 52.1. Remedy: Check it with the check method for [AL. 52.1].
52.6 Excess droop pulse during servo-off	Cause: (1) Servo motor shaft was rotated by external force. (2) Servo-on was enabled while servo motor was rotating. (3) Controller malfunctioning. (4) Encoder or servo motor malfunctioning. (5) Servo amplifier malfunctioning. Remedy: Review the machine. Review the timing of the servo-on. Replace the controller. Replace the servo motor. Replace the servo amplifier.
54.1 Oscillation detection error	Cause: (1) Servo system is unstable and oscillating. (2) Resonance frequency changed due to deterioration. (3) An encoder is malfunctioning. Remedy: Adjust servo gain (auto tuning) and set machine resonance suppression filter. Change setting value of machine resonance suppression filter. Replace the servo motor.
56.2 Over speed during forced stop	Cause: (1) Forced stop deceleration time constant is short. (2) Torque limit has been enabled. (3) Servo system unstable and oscillating. (4) An encoder is malfunctioning. Remedy: Adjust the deceleration time constant. Review the torque limit value. Adjust servo gain (machine resonance suppression filter). Replace the servo motor.
56.3 Estimated distance over during forced stop	Cause: (1) Forced stop deceleration time constant is short. (2) Torque limit has been enabled. (3) An encoder is malfunctioning. Remedy: Adjust the deceleration time constant. Review the torque limit value. Replace the servo motor.
61.1 Point table setting range error	Cause: (1) “1” or “3” was set to auxiliary function of point table (No. 31 or No. 255). Remedy: Correct the settings.
69.1 Forward rotation-side software limit detection	Cause: (1) Command position exceeded 32 bits when software limit activated. (2) Command position exceeded 30 bits from value set when software limit activated. (3) Controller malfunctioning. (4) Noise interference. Remedy: Set the command position correctly. Set [Pr. PT15] to [Pr. PT18] correctly. Replace the controller. Take countermeasures against noise.
69.2 Reverse rotation-side software limit detection	Cause: See Cause for 69.1. Remedy: Check it with the check method for [AL. 69.1].
69.3 Forward rotation stroke end detection	Cause: (1) Command position exceeded 30 bits from detected position after LSP detection. (2) Forward rotation stroke limit switch not connected to LSP. (3) Controller malfunctioning. (4) Noise interference. Remedy: Check the operation pattern. Connect it correctly. Replace the controller. Take countermeasures against noise.
69.4 Command excess error (Reverse rotation stroke end detection)	Cause: (1) The command position exceeded 30 bits from the detected position after the detection of LSN (Reverse rotation stroke end). Remedy: Check the operation pattern. Cause: (2) The reverse rotation stroke limit switch is not connected to LSN correctly. Remedy: Connect the limit switch correctly. Cause: (3) The controller is malfunctioning. Remedy: Replace the controller. Cause: (4) Something near the device caused noise/interference. Remedy: Take countermeasures against noise/environment.
86.1 Network communication error 1	Cause: (1) A network cable was disconnected. Remedy: Turn off the servo amplifier, then connect the network cable correctly. Cause: (2) The wiring of the network cable was incorrect. Remedy: Wire it correctly. Cause: (3) A network cable was disconnected (malfunction). Remedy: Replace the network cable. Cause: (4) The network was disconnected by a wrong procedure. Remedy: Perform the disconnection procedure correctly. Cause: (5) Data transmission from the controller was interrupted. Remedy: Review the controller communication setting. Cause: (6) The setting of the controller is incorrect. Remedy: Review the controller setting. Cause: (7) Noise or ambient temperature issue. Remedy: Take countermeasures against the cause (noise reduction, environment). Cause: (8) The servo amplifier is malfunctioning. Remedy: Replace the servo amplifier. Cause: (9) The controller is malfunctioning. Remedy: Replace the controller.
86.4 Network communication error 4	Cause: See causes for [AL. 86.1]. Remedy: Check with the check method for [AL. 86.1].
86.5 Network communication error 5	Cause: See causes for [AL. 86.1]. Remedy: Check with the check method for [AL. 86.1].
8A.1 USB/Serial communication time-out error	Cause: (1) Communication commands have not been transmitted. Remedy: Transmit a command. Cause: (2) A communication cable was disconnected. Remedy: Replace the communication cable. Cause: (3) The servo amplifier is malfunctioning. Remedy: Replace the servo amplifier.
8A.2 Modbus RTU communication time-out error	Cause: (1) Communication commands have not been transmitted. Remedy: Transmit a command. Cause: (2) A communication cable was disconnected. Remedy: Replace the communication cable. Cause: (3) The servo amplifier is malfunctioning. Remedy: Replace the servo amplifier.
8C.1 Network module communication error 1	Cause: (1) The servo amplifier is malfunctioning. Remedy: Replace the servo amplifier. Cause: (2) Something near the device caused it (Noise, temp). Remedy: Take countermeasures against its cause.
8C.2 to 8C.7 Network module communication error 2-7	Cause: Internal network module communication error. Remedy: Check with the check method for [AL. 8C.1].
8E.1 USB/Serial communication receive error	Cause: (1) The setting of the personal computer, etc. is incorrect. Remedy: Correct the settings. Cause: (2) A communication cable is malfunctioning. Remedy: Replace the communication cable. Cause: (3) The servo amplifier is malfunctioning. Remedy: Replace the servo amplifier.
8E.2 USB/Serial communication checksum error	Cause: (1) The setting of the personal computer, etc. is incorrect. Remedy: Correct the settings.
8E.3 USB/Serial communication character error	Cause: (1) The transmitted character is out of specifications. Remedy: Correct the transmission data. Cause: (2) The communication protocol is failure. Remedy: Modify the transmission data according to the communication protocol. Cause: (3) The setting of the personal computer, etc. is incorrect. Remedy: Correct the settings.
8E.4 USB/Serial communication command error	Cause: Same causes as 8E.3 (Command out of spec, protocol failure, or settings incorrect). Remedy: Correct transmission data, modify protocol data, or correct settings.
8E.5 USB/Serial communication data number error	Cause: Same causes as 8E.3 (Data number out of spec, protocol failure, or settings incorrect). Remedy: Correct transmission data, modify protocol data, or correct settings.
8E.6 Modbus RTU communication receive error	Cause: (1) The setting of the controller/amplifier is incorrect (baud rate, parity, etc). Remedy: Review the settings. Cause: (2) A communication cable is malfunctioning. Remedy: Replace the communication cable. Cause: (3) The servo amplifier is malfunctioning. Remedy: Replace the servo amplifier.
8E.7 Modbus RTU communication message frame error	Cause: (1) The communication protocol is failure. Remedy: Modify the transmission data according to the communication protocol. Cause: (2) The setting of the controller/amplifier is incorrect. Remedy: Review the settings.
8E.8 Modbus RTU communication CRC error	Cause: Check it with the check method for [AL. 8E.7]. Remedy: See remedies for [AL. 8E.7].
88._ / 8888._ Watchdog	Cause: (1) A part in the servo amplifier (CPU) is failure. Remedy: Replace the servo amplifier.
90.1 Home position return incomplete warning	Cause: (1) An automatic operation was executed while the home position return did not complete. Remedy: Execute a home position return. Cause: (2) Positioning operation executed without home setting after absolute position erased [AL. 25]. Remedy: Check battery voltage/cable, remove failure, and execute home position return. Cause: (3) (Indexer method) Home position return not executed after home pos return completion 2 was off. Remedy: Execute a home position return. Cause: (4) (Indexer method) [AL. E3] occurred simultaneously. Remedy: Remove the cause of [AL. E3] and execute a home position return. Cause: (5) Home position return completion 2 turned off after execution. Remedy: Check conditions in “MR-JE-_A Servo Amplifier Instruction Manual (Positioning Mode)”. Cause: (6) Software stroke limit detected. Remedy: Move machine within limit range and execute home position return.
90.2 Home position return abnormal termination	Cause: (1) A home position return speed did not decelerate to a creep speed. Remedy: Review the dog position or parameter values (speeds, travel distance). Cause: (2) The proximity dog is not connected to DOG. Remedy: Connect it correctly. Cause: (3) A stroke limit was detected after home position return started. Remedy: Connect stroke limit correctly or review position of stroke limit. Cause: (4) Deceleration from home position return speed/creep speed failed at the indexer method. Remedy: Review positional relationship of stroke limit or parameters (speeds, decal time, shift distance).
90.5 Z-phase unpassed	Cause: (1) The Z-phase signal was not detected normally. Remedy: Review the Z-phase signal and wirings. Cause: (2) A home position return was executed while the servo motor did not pass the Z-phase. Remedy: Review the setting position of the home position return start and proximity dog.
91.1 Main circuit device overheat warning	Cause: (1) The ambient temperature of the servo amplifier has exceeded 55 °C. Remedy: Lower the ambient temperature. Cause: (2) The close mounting is out of specifications. Remedy: Use it within the range of specifications.
92.1 Encoder battery cable disconnection warning	Cause: (1) The battery cable is not connected to CN4. Remedy: Connect it correctly. Cause: (2) A battery cable was disconnected (or malfunction). Remedy: Replace or repair the cable. Cause: (3) The battery voltage is low (consumed). Remedy: Replace the battery. Cause: (4) An encoder cable was disconnected. Remedy: Replace or repair the cable.
92.3 Battery degradation	Cause: (1) The battery voltage is low (consumed). Remedy: Replace the battery. Cause: (2) The battery has deteriorated. Remedy: Replace the battery.
96.1 In-position warning at home positioning	Cause: (1) INP (In-position) did not turn on within the specified time during home positioning. Remedy: Adjust gains, remove cause of droop pulse, or make home position setting.
96.2 Command input warning at home positioning	Cause: (1) A command is inputted at home positioning. Remedy: Input it after home positioning. Cause: (2) Creep speed is high. Remedy: Decelerate the creep speed and make home position setting.
96.3 Servo off warning at home positioning	Cause: (1) A home positioning was executed during servo-off. Remedy: Turn to servo-on, and then execute the home positioning.
97.1 Program operation disabled warning	Cause: (1) Started a program while the program operation was disabled. Remedy: Cycle the power of the servo amplifier.
97.2 Next station position warning	Cause: (1) An abnormal value was specified to a signal input of the next station position. Remedy: Review the parameter setting or next station position input signal. Cause: (2) The power was not cycled after the number of stations per rotation was changed. Remedy: Cycle the power of the servo amplifier.
98.1 Forward rotation-side software stroke limit reached	Cause: (1) A software limit was set within the actual operation range. Remedy: Set [Pr. PT15] to [Pr. PT18] correctly. Cause: (2) A point table of the position data which exceeds the software limit was executed. Remedy: Set the point table correctly. Cause: (3) A software limit was reached using JOG or manual pulse generator. Remedy: Execute operation within limit. Adjust JOG speed/parameters.
98.2 Reverse rotation-side software stroke limit reached	Cause: See causes for [AL. 98.1]. Remedy: Check with the check method for [AL. 98.1].
99.1 Forward rotation stroke end off	Cause: (1) The forward rotation stroke limit switch is not connected. (2) The forward rotation stroke limit was exceeded during driving. Remedy: Connect the limit switch correctly. Check the operation pattern and ensure limit switch status.
99.2 Reverse rotation stroke end off	Cause: (1) The reverse rotation stroke limit switch is not connected. (2) The reverse rotation stroke limit was exceeded during driving. Remedy: Connect the limit switch correctly. Check the operation pattern.
9B.1 Excess droop pulse 1 warning	Cause: (1) Servo motor power cable disconnected. (2) Incorrect U/V/W connection. (3) Incorrect encoder cable connection. (4) Torque limit enabled. (5) Collision with machine part. (6) Insufficient torque (load too high). (7) Power supply voltage dropped. (8) Acceleration/deceleration time too short. (9) Position loop gain is small. (10) Motor shaft rotated by external force. (11) Encoder malfunctioning. Remedy: Repair or replace servo motor power cable. Connect U/V/W wiring correctly. Connect encoder cable correctly. Increase the torque limit value. Check operation pattern and clear collisions. Reduce load, review operation pattern, or use larger capacity motor. Check power supply voltage and capacity. Increase acceleration/deceleration time constant. Increase the position loop gain ([Pr. PB08]). Review machine setup if external force is rotating shaft. Replace the servo motor.
9B.4 Error excessive warning during 0 torque limit	Cause: The torque limit value is set to 0. Remedy: Do not input a command while the torque limit value is 0.
9F.1 Low battery	Cause: (1) Battery cable not connected to CN4. (2) Battery voltage is low (less than 4.9 V DC). Remedy: Connect the battery cable correctly. Replace the battery.
E0.1 Excessive regeneration warning	Cause: Regenerative power exceeded 85% of the permissible power of the built-in resistor or option. Remedy: Reduce the frequency of positioning. Increase the deceleration time constant. Reduce the load. Use a regenerative option if not currently used.
E1.1 – E1.8 Thermal overload warning 1	Cause: The load was over 85% of the alarm level for thermal overload (during operation or stop). Remedy: Check effective load ratio. Reduce load or operating frequency. Refer to specific checks for [AL. 50] or [AL. 51].
E3.1 Multi-revolution counter travel distance excess	Cause: Travel distance from home position is 32768 rev or more. Remedy: Review operation range. Execute home position return again. Cycle power and perform home position return.
E3.2 Absolute position counter warning	Cause: (1) Noise or ambient temperature issue. (2) Encoder malfunctioning. Remedy: Take countermeasures against noise/temperature. Replace the servo motor.
E3.4 Absolute positioning counter EEP-ROM writing frequency warning	Cause: Home position renewed twice or more in 10 minutes, or operation conditions violated (Speed/Gear teeth ratio). Remedy: Set command speed within conditions. Set gear teeth on machine side within conditions. Cycle power and perform home position return again.
E4.1 Parameter setting range error warning	Cause: A parameter was set out of range with the servo system controller. Remedy: Set the parameter within the valid range.
E6.1 Forced stop warning	Cause: (1) EM2/EM1 (Forced stop) turned off. (2) External 24V DC not inputted. (3) Servo amplifier malfunctioning. Remedy: Ensure safety and turn on EM2/EM1. Input the 24 V DC power supply. Replace the servo amplifier.
E7.1 Controller forced stop input warning	Cause: (1) Forced stop signal from controller inputted. (2) Alarm occurred in another servo amplifier. (3) Forced stop signal inputted via communications (Modbus/CC-Link). Remedy: Ensure safety and cancel the forced stop signal of the controller. Remove the cause of the alarm in the other servo amplifier.
E8.1 Decreased cooling fan speed warning	Cause: (1) Foreign matter caught in fan. (2) Cooling fan reached end of life. Remedy: Remove foreign matter. Replace the servo amplifier (fan replacement).
E9.1 Servo-on signal on during main circuit off	Cause: (1) Bus voltage less than 215 V DC. (2) Servo amplifier malfunctioning. Remedy: Review wiring and power supply capacity. Replace the servo amplifier.
E9.2 Bus voltage drop during low speed operation	Cause: Bus voltage dropped while servo motor rotating at 50 r/min or less. Remedy: Review power supply capacity. Increase acceleration time constant.
EC.1 Overload warning 2	Cause: Load is too large or capacity is not enough (operation over rated output repeated). Remedy: Reduce the load. Replace with a larger capacity servo motor.
ED.1 Output watt excess warning	Cause: Output wattage (speed x torque) exceeds 120% of rated output continuously. Remedy: Reduce servo motor speed. Reduce the load.
F0.1 Instantaneous power failure tough drive warning	Cause: The power supply voltage dropped. Remedy: Check checks for [AL. 10.1] (Power supply checks).
F0.3 Vibration tough drive warning	Cause: Machine resonance suppression filter value changed frequently. Remedy: Set the machine resonance suppression filter manually. Check machine status for screw looseness.
F2.1 Drive recorder – Area writing time-out	Cause: The Flash-ROM is malfunctioning. Remedy: Disconnect cables (except power), check repeatability. Replace the servo amplifier.
F2.2 Drive recorder – Data miswriting	Cause: Data not written to drive recorder area. Remedy: Replace the servo amplifier.
F3.1 Oscillation detection warning	Cause: Oscillation detected. Remedy: Check methods for [AL. 54.1].
F4.4 Target position setting range error	Cause: Target position set out of range. Remedy: Set target position correctly. Cancel warning (turn on C_ORST).
F4.6 Acceleration time constant setting error	Cause: Acc/Decel time constant set out of range. Remedy: Set acceleration/deceleration time constants correctly. Cancel warning (turn on C_ORST).
F4.8 Control command input error	Cause: Unit set to degree and relative position command inputted. Remedy: Turn off Controlword bit 6. Cancel warning (turn on C_ORST).
F4.9 Home position return type error	Cause: Home position return type set out of range ([Pr. PT45]). Remedy: Set home position return type correctly. Cancel warning (turn on C_ORST).
F5.1 Cam data – Area writing time-out	Cause: Flash-ROM malfunctioning. Remedy: Replace the servo amplifier.
F5.2 Cam data – Miswriting	Cause: Cam data was not written correctly. Remedy: Cycle power, perform writing again. Initialize cam data and write again. Replace servo amplifier if recurrent.
F5.3 Cam data checksum error	Cause: (1) Checksum mismatch after power cycle. (2) Checksum mismatch after temporal writing. (3) Flash-ROM malfunctioning. Remedy: Write cam data again and cycle power. Perform temporal writing again. Replace the servo amplifier.
F6.1 Cam axis one cycle current value restoration failed	Cause: Feed current value outside stroke in reciprocating motion pattern. Remedy: Move feed current value within stroke. Set cam standard position within stroke.
F6.2 Cam axis feed current value restoration failed	Cause: Difference between restored value and command position is bigger than “in-position range”. Remedy: Calculate cam axis feed current value, move command position, start cam control. Set a larger value for “in-position range”.
F6.3 Cam unregistered error	Cause: (1) Cam data never written. (2) Specific Cam No. not written. (3) Cam data changed due to malfunction. Remedy: Write the cam data. Replace the servo amplifier (if data changed by malfunction).
F6.6 Cam control inactive	Cause: (1) Power not cycled after writing data. (2) Cam control command turned on during servo-on. (3) Cam control command turned on while motor driving. (4) Home position return incomplete. (5) Servo-off occurred during cam control. (6) Home position erased. (7) Stopped at software limit. (8) Stopped at stroke limit. Remedy: Cycle the power. Turn on cam control command during servo-on. Turn on cam control command while travel completion is on. Perform home position return. After servo-on, turn on cam control command again. Retract from limit and command again.
AA The display shows “AA”	Cause: (1) Servo system controller power off. (2) SSCNET III cable disconnected. (3) Previous axis servo amplifier power off. (4) Amplifier-less operation enabled. Remedy: Switch on power of servo system controller. Replace/Connect SSCNET III cable. Check power of previous axis amplifier. Disable amplifier-less operation function.
Ab The display shows “Ab”	Cause: (1) Incompatible controller connected. (2) Axis No. setting incorrect. (3) Communication cycle mismatch. (4) SSCNET III cable disconnected. (5) Servo amplifier malfunctioning. Remedy: Connect a compatible controller. Set Axis No. correctly. Set communication cycle correctly. Connect cables correctly. Replace the servo amplifier.
b## The display shows “b##” (Test Mode)	Cause: The test operation mode is enabled ([Pr. PC05] or [Pr. PC60]). Remedy: Cancel the test operation mode.
dEF The display shows “dEF”	Cause: Initializing point table/program ([Pr. PT34] = 5001). Remedy: Wait approx. 20s for initialization.
Display Off The display turned off	Cause: (1) External I/O terminal shorted (CN1, CN2, CN3). (2) Power not inputted. (3) Power supply voltage dropped. Remedy: Review wiring of I/O signals. Turn on the power. Increase power supply voltage.
Motor Issue The servo motor does not operate	Cause: (1) Wiring U/V/W incorrect. (2) Encoder cable connected to wrong axis. (3) System in test operation mode. (4) Motor-less operation enabled. (5) Torque limit enabled or load too large. Remedy: Connect wiring correctly. Connect encoder cable to correct amplifier. Check for alarms. Cancel test operation mode. Disable motor-less operation. Reduce load or cancel torque limit.