Scan Motor Cogging

When moving the motor, position-dependent torque fluctuations occur due to the cogging torques between the magnets. This can be compensated by determining appropriate cogging coefficients in the control. The "Scan Motor Cogging" function determines and saves these coefficients (8010:61). It is a good idea to add the measured cogging coefficients to the start-up list after a successful scan.

Executing the scan

CAUTION

The motor shaft moves during the scan procedure

Injuries and damage to property are possible.

Maintain a safe distance to the motor and the moving mechanism.
Ensure that the motor shaft can move freely.

Requirements

Stable operation in the CSP operation mode. See chapter Selection of the operation mode.
An encoder is connected and configured.
The encoder has at least 256 increments per revolution.

1. Remove any load from the motor shaft.

2. Write the command 0x8009 to the register FB00:01 "Request".
Scan Motor Cogging 1:

The scan runs.

The value of the FB00:02 register shows the progress of the scan.
The values 100_dec…199_dec correspond to 0... 99 %.

3. Wait until the register FB00:02 "Status" has one of the following values: 0, 1, 2, 3.

Value 0: The scan has been successfully completed.

Value 3: Error. See chapter Error diagnosis.

4. Check Diag History: the error 0x8420 means that the controller is insufficiently optimized.

You can enable cogging compensation in the CoE parameter 8010:05 "Enable cogging torque compensation".