Commutation detection

 

Procedure

 

INFORMATION

When using closed loop control, a "commutation detection" must always be carried out after the system starts. Otherwise you will receive an error message.

INFORMATION

The motor axis must be able to rotate freely during the commutation detection. There must be no external torque to counteract this.

With closed-loop control, an absolute reference between the encoder position and the pole pitch of the motor is required for control. This reference is established using commutation detection. Commutation detection is carried out according to the following procedure:

  • The state machine is in the "Switch-on inhibited" state.
  1. Send the "Switch off voltage" command, see 0x8100-01 – Control word bit 3 – 0: xx0x.
    • The function module shows the status "Switch-on inhibited".
  2. Specify a current setpoint equal to 80% of the nominal motor current, see 0x8600-03 – Current – Setpoint.
  3. Set the encoder to "Closed loop," see 0x8F00-01 – Encoder feedback configuration and enter the value 3 for "Closed loop."
  4. Select the "Commutation determination for closed loop" operating mode, see 0x8280-01 – Setpoint operating mode and enter the value 15.
  5. Send the "Switch off" command, see 0x8100-01 – Control word bit 3 – 0: x110.
    • The module shows the status "Ready to switch on".
  6. Send the "Switch on" command, see 0x8100-01 – Control word bit 3 – 0: x111.
    • The module shows the "Switched on" status.
  7. Send the "Enable operation" command, see 0x8100-01 – Control word bit 3 – 0: 1111.
    • The function module shows the status "Operation enabled" and moves 2 full steps. Commutation detection is completed when bit 10 for "Target reached" is set in "0x8100-02 – Status word". The drive is then ready for position control and speed control.