The D/A output controls the hydraulic proportional valve, and the keyboard function chip controls the processing of the keyboard key value through the interrupt service program. Converted to a display font of an LCD display by a timer interrupt service routine. And at intervals, refresh to the display buffer of the LCD display. All input switch ports are equipped with optocoupler isolation processing, and all switch output ports are equipped with solid state relays for isolation and amplification. The analog D/A output is isolated and amplified by a thyristor integrated module. In order to prevent the external interference of the single-chip system, the power supply system uses the method of isolating the control transformer and turning off the power supply. The AC contactor control circuit controls the transformer by isolation. The status of each input port is read and sent to the mapping storage buffer, and the data to be output is mapped to the storage buffer content and sent to each output port. The system control program can also associate the input port with the partial control bit of the mapping storage buffer of the output port, so that the output port directly reflects the state change of the input port, and can also manually control the machine table feed and the tool turret index. The implementation of such functions. In the vertical and horizontal feed directions of the table, there are in-situ limit switches, top position limit switches and variable speed switches. The variable speed switch enables two shifts in the longitudinal feed direction of the table, from fast forward to semi-fast forward, and then from semi-fast forward to work advance. The shifting direction of the table is realized in one direction, that is, from fast forward to work. The change of the feed rate is realized by the numerical control system controlling the opening of the electromagnetic proportional valve through the thyristor integrated module. The shift control is realized by controlling the combined control of the direction control of the electromagnetic on-off valve by the speed of the electromagnetic proportional valve. When the variable speed switch touches the module for the first time, the table is changed by the fast forward and fast forward electromagnetic proportional valve under the control signal, and the oil supply valve switch is once reduced. When the variable speed switch touches the module for the second time, the oil supply is provided. The valve switch changes again, and the table changes from fast forward to work, as shown in the principle of shift control. At the time of starting up, the main program will detect whether the hydraulic servo system of the machine tool starts the oil pump motor. If the CNC system is not activated, the output interface will be blocked and a message will be displayed on the LCD screen. In order to prevent the uncertainty of the instantaneous state of the system when the power is turned on, the output circuit is instantaneously turned on. In the output control circuit of the numerical control system, the function of the power-on delay on-off output control circuit is added. The actual use indicates that the system malfunction can be effectively prevented, and the stability and anti-interference ability of the system are improved. Summarize the numerical control system based on single-chip microcomputer. For the machine with the general conventional technical performance requirements, the machining system with the hydraulic drive system as the servo system can meet the functional requirements. It can interface well with LCD liquid crystal display. The system monitor controls the working state of the entire system. After taking the necessary anti-interference measures, the system works very stable. However, because the main frequency of the MCU is not too high, the response speed of the whole system is not too high. It is not suitable for machine tools with fast moving speed, more functions and high response speed. (Finish) Car Jack,Trolley Jack,Scissor Jack,Car Jack Lift jinyunzhaoshigongjuyouxiangongsi , https://www.zscarjack.com