Diagnostics opmode

This operational mode allows triggering diagnostics OS commands. The following OS commands can only be executed when the drive is in this mode and when the CiA402 state is Operation enabled:

  • Command 4: Motor phase order detection

  • Command 5: Commutation offset detection

  • Command 6: Open phase detection

  • Command 7: Pole pair detection

  • Command 8: Phase resistance measurement

  • Command 9: Phase inductance measurement

  • Command 10: Torque constant measurement

To select Diagnostics opmode, the value of -2 must be written to the object 0x6060 Modes of operation. When this opmode is selected and the transition to Operation enabled is performed, the brake will only be disengaged if the encoder index needs to be found. Once this procedure is done, the brake will be engaged again and object 0x6041 Statusword will reflect that the drive is in Operation enabled state. When no OS command is running, the motor control is disabled.


Always ensure that the brake is engaged or disengaged depending on the command that is executed:

  • Command 4 rotates the rotor.

  • Command 5 rotates the rotor when the selected method is 0 or 1.

  • Command 6 does not need to rotate the rotor. In case a brake is attached, it may stay engaged during this command.

  • Command 7 rotates the rotor.

  • Command 8 rotates the rotor.

  • Command 9 rotates the rotor.

  • Command 10 rotates the rotor.

For example, before running a diagnostics OS command that requires movement, the user should disengage the brake. When the OS command is finished the user should engage the brake again, so that the load does not fall. An exception to this would be if the user is planning to execute another diagnostics OS command that requires movement, because in that case it could run it right after, so the motor control would be disabled just for a few milliseconds.