Small controllers may omit overload and overcurrent protection devices. At this time, the external overcurrent protection circuit is used to avoid excessive current. Some small motors have built-in overload protection, which can automatically open circuit to avoid overload in case of overload. Larger motors will have overload relays or temperature sensing relays added to the controller, as well as fuses or circuit breakers to avoid overcurrent. Automatic motor controllers may also include limit switches or other devices to protect the machinery.

CNC programmable stepper motor controller can form a complete stepper motor control system with stepper motor driver and stepper motor, and can control three stepper motors to run at different times. This controller uses computer-based programming language, and has input, output, count and other instructions. It has the characteristics of flexible programming and wide application range, and can be widely used in various control automation fields.