Types of CNC Controller

Different types of CNC controllers are available in the market and can be categorized into three main segments based on functionality and the types of machines they are used with. These segments include microcontroller-based, PC-based, and industrial OEM controllers. The schematic diagram illustrates the different types of CNC controllers.

Microcontroller-based CNC controller:

A microcontroller is a circuit system based on a microprocessor that includes a CPU, internal memory, internal beat circuit, and I/O terminal. All these components are integrated into a single chip to maximize efficiency. G-code programming language is converted by a personal computer into the microcontroller programming language. The microcontroller interprets the data received from the computer and drives the stepper motors in a CNC machine. Microcontrollers such as Arduino and Raspberry Pi are commonly used in simple and open-loop CNC control systems with two to three axes. Microcontroller-based CNC systems find applications in CNC plotters and CNC routers. The following picture depicts a typical CNC system configuration with a microcontroller-based CNC controller.

 

PC-based CNC controller:

PC-based CNC machine tool control software and hardware toolkits allow users to create and customize their own controllers for 2 to 3-axis CNC machine tools using a standard personal computer. Popular software programs like Mach-3 & Mach-4, LinuxCNC, and Flashcut are installed on a computer, and stepper motors are driven by a motion control board or a motor driver unit. These boards can be connected to a computer using USB or Ethernet cables. PC-based CNC controllers are commonly used in applications such as CNC laser cutting, plasma cutting, and simple 2 to 3-axis CNC milling/turning. The following picture illustrates a typical CNC system configuration with a PC-based CNC controller.

Industrial OEM CNC controller:

This type of controller is a comprehensive CNC control system that can handle various levels of complexity, from simple point-to-point linear control to advanced algorithms with multiple axes of control. Servo motors are used for precise control, and motor position feedback is obtained through encoders or resolvers. Industrial communication protocols such as Attached Resource Computer Network (ARCNET), Controller Area Network Bus (CANbus), and Process Fieldbus (PROFIBUS) are utilized. Leading controller manufacturing companies like SIEMENS, FANUC, and HAAS develop their own controllers with numerous models. The modern machining industry extensively employs these controllers for machines such as CNC milling/turning, grinding, and 5-axis machining. The following picture shows a typical CNC system configuration with an OEM CNC controller.