Steppermotor control with controller - SMCI47-S / CANopen

In addition to the many features of the SMCI47 stepper motor positioning control, the new SMCI47-S variant offers two important technological innovations:

1. Closed-Loop current control (sinusoidal commutation via the encoder): In contrast to conventional stepper motor positioning controls where only the motor is actuated or the position adjusted via the encoder, sinusoidal commutation controls the stator magnetic field as in a servomotor via the encoder. The stepper motor acts in this operating mode as nothing more than a high pole servomotor, i.e. the classic stepper motor noises and resonances vanish. As the current is controlled, the motor can no longer lose any steps up to its maximum torque. If the driver sees that the rotor is falling behind the stator field due to overload, adjustments are made with optimal field angle and increased current. In the opposite case, i.e. if the rotor is running forward due to the torque, the current is automatically reduced so that current consumption and heat development in the motor and driver are very much lower compared to normal controlled operation.

2. In the CANopen version an optional logic supply 24V is possible via the CAN bus. This allows the power to be switched off for reasons of operating safety, for example, if the user intervenes manually in the machine. Nevertheless, the processor can continue to run via the logic supply and the encoder signals, enabling identification of shifts of the axes by the users.

The demo applications for the CANopen version function with all CAN adapters from IXXAT.