Along with the rapidly development of technology, electronic technology are widely used in many fields of country economy such as industry, agriculture, traffic, transportation, national defense etc. While remote data acquisition is an important means of information collection in electronic technology is an important tool used in science exploring and producing activity for man to understand the world.
This thesis--- the design of remote data acquisition terminal I/O interface module, is to solve the process, which information data in equipment transmits to host computer by 485interface.This thesis also puts forward a data acquisition system based on Keil RXT51 Tiny real-time system in equipment. This system uses in ModBus protocol, and collects monitored objects by state/simulation collection station. All of the objects are converted into MCU via light coupling, then send data to computer. And the link between MCU and computer is by RS-485. The chief task is to complete the design of soft hardware, make this system stable and convenient, also have strong universal property and practicability.