The CNC Controller

The CNC controller is the brain of a CNC system. A controller completes the all important link between a computer system and the mechanical components of a CNC machine. The controller's primary task is to receive conditioned signals from a computer or indexer and interpret those signals into mechanical motion through motor output. There are several components that make up a controller and each component works in unison to produce the desired motor movement.

The word “controller” is a generic term that may refer to one of several devices, but usually refers to the complete machine control system. This system may include the protection circuitry, stepper or servo motor drivers, power source, limit switch interfaces, power controls, and other peripherals. Owners, operators, designers, and builders of CNC devices should understand the tasks performed by these components and how they affect machine performance.

The following sections will discuss the primary task of each component in the controller and how they work together to create a complete CNC system.