Nidec Control Techniques Digitax SF Servo Drive

Fault Code and MeaningCause and Remedy
900

Encoder overheat detection

Cause:

The temperature inside the absolute encoder has exceeded the temperature value specified by Encoder: Overheat detection – Value (267.0). An alarm can be output in place of the warning.



Remedy:

Reduce the ambient temperature and improve thermal radiation conditions. Check the setting of Encoder: Overheat detection – Value (267.0).



Reset Method: After eliminating the cause, then input RESET signal to the RESET terminal on the connector CN1.
901

Encoder battery voltage drop error detection

Cause:

The battery voltage of the absolute encoder has dropped below the voltage set by Encoder: Battery voltage drop detection – Value (268.0).



Remedy:

Replace the battery in the absolute encoder. Check the Encoder: Battery voltage drop detection – Value (268.0).



Reset Method: After eliminating the cause, then input RESET signal to the RESET terminal on the connector CN1.
902

Emergency stop

Cause:

The E-STOP control terminal digital input is open.



Remedy:

Close the E-STOP control terminal digital input. Check for proper I/O connections.



Reset Method: After eliminating the cause, then input RESET signal to the RESET terminal on the connector CN1.
903

Encoder communication warning

Cause:

Failed to obtain ABS encoder temperature and battery voltage data.



Remedy:


  • Check for wire disconnection or loose connection of pins.

  • Keep the cable length no longer than 20 m.

  • Check for noise interference:


    • Use a shielded twist-pair cable.

    • Keep the encoder cable away from the motor power cable.

    • Connect Ground/Earth FG firmly.

    • Use ferrite core for the motor power cable and encoder cable.


  • If any of the above didn’t resolve the issue, please contact the supplier.




Reset Method: After eliminating the cause, then input RESET signal to the RESET terminal on the connector CN1.
904

Excessive position error

Cause:

The position error consecutively exceeded the setting of Position error warning detection: Value (363.0) and the setting of Position error warning detection: Delay time (365.0).



Remedy:


  • Adjust the tuning parameters.

  • Check the command from the host controller.

  • Check the wiring.

  • Verify that the brake is released.

  • Verify that the motor is not in a torque limit state per torque command limit.

  • Check the settings of Position error warning detection: Value (363.0) and Position error warning detection: Delay time (365.0).




Reset Method: After eliminating the cause, then input RESET signal to the RESET terminal on the connector CN1.
Alarm No. 0
System

Cause: Error in the control circuit. The control circuit CPU is not operating normally.



Remedy: Please contact the supplier of the drive.
Alarm No. 1
EEPROM data

Cause: Error during writing of Parameters.



Remedy: Check the interface cable and re-write the parameters.
Alarm No. 2
Product code

Cause:

  • Unable to read the product code.

  • The drive-motor pairing was wrong.

  • The encoder cable was not connected to the drive correctly (includes wiring disconnection).





Remedy: Check the motor-drive pairing. Check the encoder cable connections.
Alarm No. 4
Overspeed

Cause:

  • The motor rotational speed exceeded the rated maximum rotational speed.

  • The command from the host controller was not appropriate.

  • There were residual pulses due to drive limit switch input or other reasons.





Remedy:

  • Adjust the Tuning parameters.

  • Check the command.

  • Verify that the location of the limit sensor hasn’t shifted.


Alarm No. 5
Speed

Cause: Position control/Speed control error.

  • The command was not appropriate.

  • The load was too heavy and could not keep up with the command speed.

  • Speed error detection: Value (90.0) was not appropriate.





Remedy:

  • Check the command from the host controller.

  • Adjust the tuning parameters.

  • Check the setting of Speed error detection: Value (90.0).

  • Verify that the brake is released.

  • Verify that the motor is not in a torque limit state per torque command limit.


Alarm No. 6
Position

Cause: Position Control Error.

  • The acceleration time was too short.

  • There was wrong connection or disconnection of the motor power cable or encoder cable.

  • Position error detection: Value (87.0) was not appropriate.





Remedy:

  • Adjust the tuning parameters.

  • Check the command from the host controller.

  • Check the wiring.

  • Check the setting of Position error detection: Value (87.0).

  • Verify that the brake is disengaged.

  • Verify that the motor is not in a torque limit state per torque command limit.


Alarm No. 7
Overload

Cause:

  • Immediately after operation started: Motor did not move or moved slightly.

  • During operation: Alarm occurred at same point of motion profile.

  • Acceleration time too short.

  • Motor was not accelerating (machine collided with object).

  • Motor capacity too small (load too large).

  • Significant vibration or noise generated.

  • Tuning parameters or commands not appropriate.





Remedy: Executing overloaded motion continuously may burnout the motor.

  • Check motor power cable connections.

  • Verify user-selected motor capacity is appropriate.

  • Verify brake is disengaged.

  • Verify deceleration ratio is appropriate.

  • Check acceleration time, torque waveform, and load ratio.

  • Verify no obstacles inside work area.

  • Increase motor capacity or install a decelerator.

  • Adjust Tuning parameters.

  • Configure moderate commands (e.g., use command smoothing filter).

  • Configure countermeasures for noise (notch filter or low-pass filter).


Alarm No. 8
Command overspeed

Cause:

  • The position control input exceeded the max rotational speed.

  • The command from the host controller was not appropriate.





Remedy: Check the Pulse train command: Ratio (34.0 and 36.0). Check the commands from the host controller.
Alarm No. 9
Encoder pulse – Output frequency error

Cause: The frequency of the encoder pulse output exceeded 4 Mpps.



Remedy:

  • Check the numerator and denominator settings in the Encoder pulse output: Pulse ratio (276.0 and 278.0).

  • Check the settings of Encoder pulse output: Error detection – Frequency upper limit (285.0) and Delay time (286.0).


Alarm No. 10
Positioning command overflow /Homing failure

Cause:

  • External position command exceeded the absolute value range of ±1,073,741,823.

  • The shift amount per one of the commands exceeded the ±2,147,483,647 range.

  • Homing failed and timed out.





Remedy:

  • Select a value different from the current setting of Internal Position: Overflow detection (643.0).

  • Adjust the parameters such that the shift amount will be within the ±1,073,741,823 range.

  • Adjust the shift amount of Positioner motion, inching and test each one.

  • Adjust the Homing related parameters.


Alarm No. 11
Encoder (multi-turn counter overflow)

Cause: Multi-turn data of the encoder has exceeded the ±32,767 range.



Remedy: Check the setting of Absolute system (257.0). Verify that the multi-turn motion amount is within the ±32,767 range.
Alarm No. 12
Overheat

Cause: The control circuit temperature has exceeded the upper limit.



Remedy: Check the drive’s installation method and environment. Lower the ambient temperature to below the rating.
Alarm No. 14
Overvoltage

Cause: The power supply to the control components has exceeded the drive circuit limits.



Remedy:

  • If during deceleration: Check regeneration status. Install a braking resistor if necessary. Use a command filter and gradually decrease speed.

  • If regardless of deceleration: Verify AC Supply is within specification. Check for voltage changes during system operation.


Alarm No. 15
Power supply (AC Supply)

Cause:

  • AC Supply voltage abnormally high, low, or not present.

  • AC Supply not within input range.

  • Power supply fluctuated significantly.

  • SVON signal input without AC supply.

  • Regeneration ON status too long.





Remedy:

  • Verify AC Supply connection and timing with SVON signal.

  • Check for voltage fluctuations during operation. Provide stable power supply.

  • If during deceleration: Check for regenerative voltage warnings. Install braking resistor if needed. Use command smoothing filter.


Alarm No. 16
Encoder (received data)

Cause: Encoder data changed rapidly for a short period of time.



Remedy:

  • Check for wire disconnection or loose connection of pins.

  • Keep the cable length no longer than 20 m.

  • Check for noise interference (Use shielded twist-pair cable).

  • Keep encoder cable away from motor power cable.

  • Connect Ground/Earth FG firmly.

  • Use ferrite core for motor power cable and encoder cable.

  • If unresolved, contact supplier.


Alarm No. 17
Encoder (no response)

Cause: Encoder communications were disconnected.



Remedy: See remedy for Alarm No. 16 (Check wiring, noise, grounding, cable length).
Alarm No. 18
Encoder (circuit)

Cause:

  • Battery voltage dropped or battery disconnected (Alarm No. 21 output in this case).

  • Encoder temperature exceeded specification.

  • Anomaly of the encoder itself detected.





Remedy:

  • If using absolute system: Replace the battery, connect it, and initialize the encoder.

  • If not using absolute system: Check whether encoder temperature is within specification.

  • If unresolved, contact supplier.


Alarm No. 19
Encoder (communication)

Cause: The initial communication with the encoder failed.



Remedy: See remedy for Alarm No. 16 (Check wiring, noise, grounding, cable length).
Alarm No. 20
Encoder (multi-turn data)

Cause: Absolute encoder data changed rapidly. At startup, failed to receive multi-turn data internally.



Remedy: See remedy for Alarm No. 16 (Check wiring, noise, grounding, cable length).
Alarm No. 21
Encoder (voltage drop)

Cause: The battery voltage dropped or became disconnected. It was the first start-up after battery connection.



Remedy: Check for low battery voltage. Check for loose battery cable. Initialize the encoder.
Alarm No. 22
Voltage (control power)

Cause: The control power supply dropped.



Remedy:

  • Check the control power supply.

  • Check for insufficient control power supply capacity.

  • Check the wiring of user I/O connector 24 V (Pin 1 and Pin 2).


Alarm No. 23
Switch circuit

Cause: Control circuit has failed.



Remedy: Please contact the supplier of the drive.
Alarm No. 24
Overcurrent

Cause: Anomaly of motor control current inside of the drive has been detected.



Remedy:

  • Check motor power cable (Grounding fault, wiring mistake).

  • Check Tuning parameters and motor motion patterns (Increase acceleration/deceleration time).

  • Enable/Disable Position command filter 1 and 4.

  • Allow motor motion by disengaging brake/stopper.

  • Check encoder cable (Connection, twist-pair).

  • If unresolved, contact supplier.


Alarm No. 25
Inverter 1

Cause: Anomaly in the control circuit has been detected.



Remedy:

  • Check the motor power cable.

  • Check for Grounding fault.

  • Check for wiring mistake in motor power cable connections.

  • If unresolved, contact supplier.


Alarm No. 26
Inverter 2

Cause: Anomaly in the control circuit has been detected. SERVO ON timed out.



Remedy:

  • Check the motor power cable.

  • Check for Grounding fault.

  • Check for wiring mistake in motor power cable connections.

  • If unresolved, contact supplier.


Alarm No. 27
Current sensor

Cause: The ambient temperature of the current sensor was high. Anomaly of the current sensor has been detected.



Remedy: Check the installation method and environment. If unresolved, contact supplier.
Alarm No. 28
Encoder (overheat)

Cause: The encoder PCB temperature has reached the upper limit.



Remedy: Check the installation method and environment of the motor. Decrease the ambient temperature of the motor below the specification.
Alarm No. 29
Voltage drop (inside the drive)

Cause: The control power voltage (5 VDC) inside the drive has dropped.



Remedy: Verify that there is no short-circuit in encoder cable connections. If the above didn’t resolve the issue, please contact the supplier of the drive.