Computerized Numerical Control

Machine tools with computerized numerical control (CNC) are used for mechanical treatment of the metal and alloy parts. The first CNC milling machine was created in 1952 at Massachusetts Institute of Technology. CNC machine tools (Numerical Control, NC) differ from the standard ones by having a Machine Control Unit (MCU), which functionally includes a Data Processing Unit (DCU) and Control Loop Unit (CLU). MCU reads data from an input data source (initially, punch cards and punch tapes, which were later replaced with magnetic carriers), and DCU converts them into control commands for the machine tool.

Upon introducing computers to the machine tool control scheme, they are called machine tools with Computer Numerical Control (CNC). In the modern manufacturing workshops all computers controlling CNC machine tools, are connected into a network controlled by the central computer, which directly controls the workshop, including downloading data into a particular machine tool. This scheme is called Distributed Numerical Control (DNC).