The control mode of bus can truly realize isochronous synchronization, because the speed of bus communication is faster, and the speed or position setting can be directly sent. Therefore, high-end servo applications are all based on bus control.
The stepper motor controls its speed, position and direction by receiving pulse current. The number of pulses determines the position of the stepper motor, the speed of the pulse determines the speed of the motor, and the direction of the pulse determines the steering of the motor. At present, the control mode of most stepping motors is to use plc to send pulses to the driver, and the driver drives the motor to run.
For occasions where many motors are needed, for example, many medical instruments have twenty or thirty shafts, if the pulse type is used, firstly, it is not easy to control, and one plc can control six or seven shafts at most. If there are more motors, multiple upper computers are needed, which requires a large space and volume, while most medical instruments are relatively small and compact.