# Encyclopedia of commonly used terms in CNC technology

In order to facilitate readers to read related CNC materials and related manuals of foreign CNC products, the commonly used CNC vocabulary and their English corresponding words are selected here. The selected CNC terms mainly refer to the international standard ISO 2806 and the People’s Republic of China national standard GB 8129-1987. And some new numerical control vocabulary that appeared in recent years.
1) Computerized Numerical Control (CNC) uses a computer to control processing functions to realize numerical control.

2) Axis (Axis) The reference direction of the machine tool components can be moved linearly or rotated along it.

3) The machine coordinate system (Machine Coordinate Systern) is fixed on the machine tool and is a Cartesian coordinate system based on the machine zero point.

4) Machine Coordinate Origin (Machine Coordinate Origin) The origin of the machine coordinate system.

5) Workpiece Coordinate System is a Cartesian coordinate system fixed on the workpiece.

6) The origin of the workpiece coordinate system (Wrok-piexe Coordinate Origin).

7) Machine zero (Machine zero) is the machine origin specified by the machine manufacturer.

8) Reference Position (Reference Position) A fixed point along the coordinate axis used for machine startup, it can use the machine coordinate origin as the reference datum.

9) Absolute Dimension/Absolute Coordinates The linear distance or angle from the origin of a coordinate system.

10) Incremental Dimension/Incremental Coordinates In a sequence of point increments, the distance or angle value of each point from the previous point.

11) Least Input Increment The smallest increment unit that can be input in the processing program.

12) Least command increment (Least command Increment) is the smallest incremental unit of command axis movement issued from the numerical control device.

13) Interpolation determines the position coordinates of multiple intermediate points between two known points on the required path or contour line according to a certain mathematical function (for example: straight line, arc or higher order function) The calculation process.

14) Linear Interpolation (Llne Interpolation) This is an interpolation method. In this method, the interpolation between two points is approached along the point group of a straight line, and the movement of the tool is controlled along this straight line.

15) Circula: Interpolation This is an interpolation method, in this method, according to the interpolation digital information between the two end points, calculate the point group that approximates the actual arc, and control the tool to move along these points , Processing arc curve.

16) Clockwise Arc (Clockwise Arc) tool reference point around the center of the trajectory, the trajectory formed by the negative angle direction rotation. The trajectory formed by the direction rotation.

17) Counterclockwise Arc (Counterclockwise Arc) is the path formed by rotating the tool reference point around the center of the path at a positive angle.

18) Manual Part Prograrnmiog (Manual Part Prograrnmiog) to manually compile part processing programs.

19) Computer part programming (Cornputer Part prograrnrnlng) Use a computer and appropriate general-purpose processing program and post-processing program to prepare the part program to obtain the processing program.

20) Absolute Prograrnming is programmed with a control word representing an absolute size.

21) Increment programming (Increment programming) is programmed with a control word indicating the size of the increment.

22) Character is a group of element symbols used to represent an organization or control data.

23) Control Character (Control Character) appears in a specific message text, which represents a character for a certain control function.

24) Address (Address) A character or a group of characters at the beginning of a control word to identify subsequent data.

25) Block Format The arrangement of words, characters and data in a block.