Data-acquisition System Based On MCU PIC16F877 (Comunication And PC Program Design)

This paper researches the PC part of universal data acquisition system. With the development of computer technology, the demand for controlling precision gets higher. In this way, it is essential to monitor important parameter of field. After the data of industry field is transformed into electrical signal by sensor, the signal is transmitted to PC for display via the serial interface of MCU. In this way, we can watch types of parameters and identify whether the parameters are correct in according to the requiring to industry , which make us take relevant controlling operation.Because the signal which serial interface output of MCU is TTL logic level, it is essential to transform TTL electrical level to RS-232 electrical level when the MCU is communicated with PC. In this paper the universal RS232/485 electrical levelconverting circuit board is designed. It can realize data transmission by the two communication level manner. By debugging, the board could meet the expected function. The signal is credibility and nicety.In this paper, the computer' s serial interface is accessed via the MSComm control in VB6.0. It can realize the asynchronous communication with MCU. The superstratum interfaces are designed with VB6. 0. It can examine and display digital signals and analog signals, and set communication port simply by asking. It has realistic meaning.