Controller
A controller is a piece of equipment that controls the operation of an electrical device.
An adjustable speed drive might consist of an electric motor and controller that is used to adjust the motor's operating speed.
The counter determines how often the motor controller will move the stepper motor one step, thus setting the rate of stepping commands which, in turn, controls motor speed. A controller is a piece of equipment that controls the operation of an electrical device.
Англійський словник Коллінза, електронний ресурс: https://www.collinsdictionary.com/