此程序是RS485从机通讯，包含3部分：接收帧程序、发送帧程序及执行命令程序。

从机通讯地址从地址开关读取4位

由于485的通信规约差别很大，这里只是提供参考，具体请参照自己的项目特点做修改,抛砖引玉。

#include<reg52.h>

#include<main.h>

#include<hy502.h> -this procedure is RS485 communications from the plane, contains three parts : a receiving fr a me procedures, Send fr a me procedures and procedures for the enforcement of the order. Communication from the address from the address switch read four of the 485 due to communication protocol vary greatly, the reference here is, Please refer to their specific project features modified to congregate.# Include