The numerical control device is the core of the entire numerical control system, and its hardware structure can be divided into a large-board structure and a functional modular structure according to the plug-in mode of each PCB circuit board in the CNC device.

(1) The CNC device with large plate structure can be composed of main circuit board, position control board, PLC board, graphic control board and power supply unit. The main circuit board is large, and the other circuits are small PCB circuit boards, which are inserted into the slots on the large printed circuit board to form a CNC device.

(2) The functional modular structure divides the entire CNC device into modules according to functions. The design of hardware and software adopts a modular design method, that is, each functional module is made into a printed circuit board with the same size (called a functional template), The control software of the corresponding functional modules is also modularized. From the design purpose of this system and the user's use point of view, this design uses a large plate structure.

There are control core circuit, position control circuit, paper tape reader interface, speed control quantity output interface, hand pulse generator interface, I/O control board interface and five small PCB circuit boards on the main circuit board (PCB circuit board). slot. The control core circuit is the basic system of the microcomputer, which consists of CPU, memory, timing and interrupt control circuit. The memory includes ROM and RAM. The ROM (using EPROM) is used to solidify the CNC system software, and the RAM stores variable data, such as stack data and control software. Temporarily store data, and have power-down protection function for variable data storage areas such as CNC machining programs and system parameters. The five slots can be inserted to protect the CNC machining program and the magnetic bubble memory board, LCD display control board, I/O interface board, stepper motor control board, etc.