本例程演示了PC机和智能型仪表如何通过RS485接口进行通信。仪表采用百特公司产XMA5000智能型专家自整定PID调节器，该仪表的通讯协议已经在例程代码中作了详细说明。该例程非常简单，旨在说明如何在VC++中使用重叠方式读写串口。这个是异步通信，昨天传那个是同步通信。-The routine demonstration of PC and intelligent instrument through RS485 communication interface. Instrumentation used Nissan Baxter XMA5000 intelligent expert self-tuning PID regulator, the instrument of communication protocols have been made in the routine code in detail. The routine is very simple, designed to show how VC++ Used to read and write serial port overlapping manner. This is asynchronous communication, Chuan yesterday that is synchronous communication.