c语言实现 通过rs232可实现上位机和下位机的通信-Modbus

#include <stdio.h> #include <dos.h> #include <conio.h> #define BUFFLEN 1024 /*定义缓冲区大小*/ #define len 50 void InitCOM(); /*PC机232串口初始化，设置波特率和缓冲区，然后打开串口开始通讯*/ void OpenPort(); /*开串口*/ void ClosePort();/*关串口*/ void send(char *);/*发送*/ void receive();/*接收*/ void covert_hex_to_binary(char *);/*十六进制转换成二进制*/ void covert_decimal_to_binary(int *);/* 十进制转二进制数 */ /*CRC校验*/ void interrupt far asyncint(); /*中断响应*/ void interrupt(*asyncoldvect)(); unsigned char Buffer[BUFFLEN]; /*定义缓冲区*/ int buffin=0; int buffout=0; /*--------------------------------------------------------------------------------------------------------------*/ main(int argc,char *argv[]) { int i; char port;/*存地址码*/ char fuction;/*存功能码*/ char reg_add_hi[2];/*存起始寄存器地址高8位*/ char reg_add_lo[2];/*存起始寄存器地址低8位*/ char reg_dat_hi[2];/*读取数据寄存器高8位*/ char reg_dat_lo[2];/*读取数据寄存器低8位*/ char port_link[2];/*用于连接命令串的地址字符*/ char fuction_link[2];/*用于连接命令串的功能字符*/ char result[12];/*用于存放各个域合成的总的串,即校验域前的几个域的集合*/ if(argc==1) { printf("No parameters value,please type like: Modbus [s]/[r]\n"); exit(1); } InitCOM(); OpenPort(); if(tolower(*argv[1])=='s') { { printf(" serial port(COM1:0/COM2:1):"); port=getche(); printf("\n"); if(port=='0') { port_link[0]='0'; port_link[1]='0'; } else if(port=='1') { port_link[0]='0'; port_link[1]='1'; } printf(" select fuction(read:r/write:w):"); fuction=getche(); printf("\n"); if(fuction=='w') { fuction_link[0]='0'; fuction_link[1]='5'; } else if(fuction=='r') { fuction_link[0]='0'; fuction_link[1]='3'; } printf(" register address(high):"); for(i=0;i<2;i++) reg_add_hi[i]=getche(); printf("\n"); printf(" register address(low):"); for(i=0;i<2;i++) reg_add_lo[i]=getche(); printf("\n"); printf(" register data(high):"); for(i=0;i<2;i++) reg_dat_hi[i]=getche(); printf("\n"); printf(" register data(low):"); for(i=0;i<2;i++) reg_dat_lo[i]=getche(); printf("\n"); if(fuction=='w') { printf(" type the data:"); /*接收数据*/ } else if(fuction=='r') { /*send();*/ } } /*for(i=0;i<2;i++)*/ /*printf("%c ",port_link[i]);*/ /*for(i=0;i<2;i++)*/ /*printf("%c ",fuction_link[i]);*/ /*for(i=0;i<2;i++)*/ /*printf("%c ",reg_add_hi[i]);*/ /*for(i=0;i<2;i++)*/ /*printf("%c ",reg_add_lo[i]);*/ /*for(i=0;i<2;i++)*/ /*printf("%c ",reg_cou[i]);*/ for(i=0;i<2;i++) { result[i]=port_link[i]; result[i+2]=fuction_link[i]; result[i+4]=reg_add_hi[i]; result[i+6]=reg_add_lo[i]; result[i+8]=reg_dat_hi[i]; result[i+10]=reg_dat_lo[i]; } /*for(i=0;i<10;i++)*/ /*printf("%c",result[i]);*/ /* printf("\n");*/ send(result); } else if(tolower(*argv[1])=='r') receive(); else printf("No parameters value,please type like: Modbus [s]/[r]\n"); /* for(i=1;i<argc;i++)*/ /* printf("%s",argv[i]);*/ /* return 0;*/ } /*--------------------------------------------------------------------------------------------------------------*/ void InitCOM()/*初始化COM1为0X3F8（COM2-2F8,COM3-3E8,COM4-2E8）*/ { outportb(0x3fb,0x80);/*通訊線控制寄存器控制字，訪問波特率除數鎖存器;向0x3fb地址写0x80,outportb()管脚定义函数，0x3f9和0x3fb都是PC里负责*/ outportb(0x3f8,0x0C);/*除數鎖存器控制字低位，定波特率*/ outportb(0x3f9,0x00);/*除數鎖存器控制字高位，定波特率*/ outportb(0x3fb,0x03); outportb(0x3fc,0x08|0x0b); outportb(0x3f9,0x01); } /*--------------------------------------------------------------------------------------------------------------*/ void OpenPort() { unsigned char ucTemp; InitCOM(); asyncoldvect=getvect(0x0c); disable(); inportb(0x3f8); inportb(0x3fe); inportb(0x3fb); inportb(0x3fa); outportb(0x3fc,0x08|0x0b); outportb(0x3f9,0x01); ucTemp=inportb(0x21)&0xef; outportb(0x21,ucTemp); setvect(0x0c,asyncint); enable(); } /*--------------------------------------------------------------------------------------------------------------*/ void interrupt far asyncint() { Buffer[buffin++] = inportb(0x3f8); if (buffin >= BUFFLEN) buffin=0; outportb(0x20,0x20); } /*--------------------------------------------------------------------------------------------------------------*/ void ClosePort(void) { disable(); outportb(0x3f9,0x00); outportb(0x3fc,0x00); outportb(0x21,inportb(0x21)&0x10); enable(); setvect(0x0c,asyncoldvect); } /*--------------------------------------------------------------------------------------------------------------*/ void send(char *result_p) { int j; unsigned int *p_crc; for(j=0; j<12; j++) printf("%c",*(result_p++)); printf("\n"); /* for(j=0; j<12; j++) /*以下5行都是4月12号加的*/*/ /* result_p+j=(unsigned char)(*(result_p+j));*/ p_crc=cal_crc(result_p,6); for(j=0;j<12;j++) printf("%d",*p_crc++); } /*--------------------------------------------------------------------------------------------------------------*/ void receive() { } /*--------------------------------------------------------------------------------------------------------------*/ unsigned int cal_crc(unsigned char *ptr, unsigned int len) { unsigned int crc=0xffff; unsigned char i; while(len!=0) { crc^=*ptr; for(i=0;i<8;i++) { if((crc&0x0001)==0) crc=crc>>1; else { crc=crc>>1; crc^=0xa001; } } len-=1; ptr++; } return crc; }