What do NC, CNC and DNC in numerical control mean respectively?

In numerical control, NC is abbreviated as digital control. CNC is computer numerical control. DNC means distributed numerical control, that is, while transmitting the program, the CNC machine tool is controlled by the computer for processing and online processing.

NC refers to the use of discrete digital information to control the operation of machines and other equipment, which can only be programmed by the operator himself. It is an automatic method to program and control a certain working process by means of numbers, characters or other symbols. NC has become a special term for NC machining.

DNC is called distributed numerical control, which is a general manufacturing term of networked numerical control machine tools. Its essence is a numerical control system distributed in the workshop, which is composed of computers and machine tools with numerical control devices by using computer network technology. DNC systems usually provide the function of embedding macro instructions. In addition, a post-processor can be developed to embed macro instructions when generating NC code.

Computer numerical control, CNC for short, is a direct combination of computer and numerical control. The computer completes numerical calculation and directly issues control instructions to participate in the control process. The control software of CNC system is written in assembly language, and different types of machine tools use different CNC systems. After CNC is turned on, CNC and PMC run at the same time.

Extended data

The control system of digital machine tools can logically process the program specified by codes or other symbolic encoding instructions. The control object of CNC machine tools can be various machining processes. The production process controlled by CNC machine tools is to send the program into the computer in digital form for calculation and processing, and generate a series of action instructions.

Computer numerical control is that a main computer centrally controls the operation of several numerical control machine tools, and the main computer is connected with the numerical control system through Ethernet. In order to realize centralized control of multiple CNC machine tools, the main computer controlling the machining unit must be able to obtain all kinds of information and data of each CNC machine tool. The meaning of CNC system is computer numerical control system.

The early DNC system mainly solved the communication problems of CNC machine tools and the management problems of CNC programs, and realized the bidirectional transmission of CNC machining programs, tool list files, machine tool parameters and tool parameters between machine tools and server computers. At the same time, the centralized management and three-dimensional simulation of NC program are realized, which greatly improves the machining efficiency.

The early DNC system is difficult to meet the needs of production management. Therefore, on the basis of communication with the bottom control system, DNC system has gradually developed data acquisition functions, including machine tool operation information, machining information, status information and some real-time information, such as real-time status data and real-time alarm data of machine tools.

Reference source; Baidu Encyclopedia-Digital Control

Reference source; Baidu encyclopedia-computer numerical control

Reference source; Baidu encyclopedia-DNC