Code

Name

Causes

Possible Solutions

Er-21

Z Pulse Correction Error

The motor is wired incorrectly.

  1. Repair motor and encoder wiring errors.

  2. Do Z Pulse Offset Tuning again.

The encoder is wired incorrectly.

You did Auto-Tuning on a coasting motor.

  1. Wait for the motor to fully stop.

  2. Do Z Pulse Offset Tuning again.

The setting for the direction of the encoder motor rotation is incorrect.

  1. Set the direction of motor rotation of the encoder in F1-05 [Encoder 1 Rotation Selection] correctly.

  2. Do Z Pulse Offset Tuning again.

The number of encoder pulses is incorrect.

  1. Set the number of encoder pulses in F1-01 [Encoder 1 Pulse Count (PPR)] correctly.

  2. Do Z Pulse Offset Tuning again.

The motor Inertia is too large.

Increase the value set in n8-02 [Pole Alignment Current Level].

Parameter b1-04 = 1 [Reverse Operation Selection = Reverse Disabled] and you did Z Pulse Offset Tuning.

  • If the machine prevents reverse rotation, disconnect the motor from the machinery, set b1-04 = 0 [Reverse Enabled], then do Z Pulse Offset Tuning. When tuning is complete, set b1-04 = 1 [Reverse Disabled].

  • If the machine does not prevent reverse rotation, set b1-04 = 0 and do Z Pulse Offset Tuning.

The motor vibrates during tuning.

  • Increase the values set in n8-03 [Pole Position Detection Time] and n8-04 [Pole Alignment Time].

  • Decrease the value set in n8-02 [Pole Alignment Current Level].

The encoder is damaged.

  • Examine the signal output from the encoder.

  • Replace the encoder.