Abstract
With the rapid development of modern electrical testing and instrumental technology,The technology of virtual instruments is widely used in control and inspectionl. It is a perfect product of Instrument and Computer technology. This design mainly achieve a DC motor control system based on virtual instruments，including the hardware design and the software programming. As a software platform., the programming language LabVIEW of the virtual instrument is the main software of this design. The entire system consists of two parts are the upper and lower machines.The LabVIEW program of the upper machine sends the control signals through the computer serial port.After the STC89C52RC microcontroller receiving the signals of the host computer, this system control the DC motor start-up , stopping, positive rotation, reverse rotation, and other actions. The hardware circuit is composed by the serial communication circuit and the DC motor control circuit. The serial communication circuit is achieved by MAX232 chip connecting with the microcomputer STC89C52RC chip. The motor control circuit is achieved by the SCM connecting with the Motor driving circuit The design of the system software includes two parts ,the LabVIEW programming and the microcontroller programming. At first, the asm51 assembly language is adopted in the SCM source programming for detecting the hardware circuit. Then , the C51 advanced language is used to writing the serial communication program for achieving the communication between the PC and the MCU. Finally, using the VISA function of the LabVIEW programming to control the DC motor.In this design, the Virtual Instruments LabVIEW reflects some advantages,such as interface intuitive, a variety of analysis,fast processing. It not only can become the basic tool of researching about motor, but also has special premises in electricity and automation system.
Keywords：LabVIEW，Microcontroller，serial communication，DC motors
