modbus_c_program.txt

单片机与其它仪表之间modbus通讯协议,用c语言编写

#define READ_COIL     01 
#define READ_DI       02 
#define READ_HLD_REG  03 
#define READ_AI       04 
#define SET_COIL      05 
#define SET_HLD_REG   06 
#define READ_FIFO     24 
#define PROTOCOL_EXCEPTION 0x81 
#define PROTOCOL_ERR  1 
#define FRM_ERR       2 


const unsigned char auchCRCHi[] = { 
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 
0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 
0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 
0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 
0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 
0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 
0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 
0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 
0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 
0x40 
} ; 

const unsigned  char auchCRCLo[] = { 
0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4, 
0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 
0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 
0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3, 
0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7, 
0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 
0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 
0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26, 
0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2, 
0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 
0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 
0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5, 
0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91, 
0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 
0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 
0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C, 
0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 
0x40 
}; 


const unsigned char char_tab[128]= 
{ 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,                        
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,                       
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,                        
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0,                       
    0, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0, 0, 0, 0, 0, 0, 0, 0, 0,     
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,                       
    0, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0, 0, 0, 0, 0, 0, 0, 0, 0,     
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0                         
}; 
    
     
const unsigned char tab_char[16]= 
{  
    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' 
}; 

const unsigned int bit_tab[]= 
{ 
    BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7,  
    BIT8, BIT9, BITA, BITB, BITC, BITD, BITE, BITF 
}; 

unsigned short crc(unsigned char *puchMsg , unsigned short usDataLen) 
{ 
    unsigned char uchCRCHi = 0xFF ; /* high byte of CRC initialized */ 
    unsigned char uchCRCLo = 0xFF ; /* low byte of CRC initialized */ 
    unsigned uIndex ;  /* will index into CRC lookup table */ 
     
    while (usDataLen--) /* pass through message buffer */ 
    { 
     
    
     uIndex = uchCRCHi ^ *puchMsg++ ; /* calculate the CRC */ 
     uchCRCHi = uchCRCLo ^ auchCRCHi[uIndex]; 
     uchCRCLo = auchCRCLo[uIndex] ; 
    } 
    return (uchCRCHi << 8 | uchCRCLo) ; 
} 

unsigned char a2toh(unsigned char *str) 
{ 
    unsigned char tmp; 
    tmp = 0; 
     
    tmp = char_tab[*str]; 
    str++; 
    tmp = tmp*16 + char_tab[* str]; 
    return tmp; 
} 

int get_bit( unsigned int data, int bit ) 
{ 
    if (bit > 16) return 0; 
    if (data & bit_tab[bit]) return 1; 
    else return 0; 
} 

void htoa(  char *str, unsigned char num) 
{ 
    unsigned char tmp; 
    tmp = num;  
    tmp = tmp & 0xf0; 
    tmp >>= 4; 
    *str = tab_char [ tmp]; 
    str++; 
    *str = tab_char [ num & 0x0f]; 
} 

int  asctortu( unsigned char *dest, unsigned char *source) 
{ 
    unsigned char *tmp; 
    unsigned char i; 
    i=0; 
    tmp = dest; 
     
    if( *source !=':') return 0; 
    source ++; 
    
    while ( *source != 0x0d) 
    { 
       *tmp = a2toh( source); 
       tmp ++; 
       source ++; 
       source ++; 
       i++; 
    } 
    source ++; 
    if ( *source != 0x0a) return 0; 
    else 
    { 
       return i; 
    } 
} 


void rtutoascii( unsigned char *dest, unsigned char *source, int lenth) 
{ 
    dest ++; 
          
    for ( ; lenth>0; lenth--) 
    {  
       htoa( dest, *source); 
       dest++; 
       dest++; 
       source++; 
     
    }    
} 


void rtutoasc( unsigned char *dest, unsigned char *source, int lenth) 

{ 
    dest ++; 
          
    for ( ; lenth>0; lenth--) 
    {  
       htoa( dest, *source); 
       dest++; 
       dest++; 
       source++; 
      
     }    
} 


unsigned char lrc(unsigned char *str,int lenth) 
{ 
    unsigned char tmp; 
    tmp = 0; 
     
    while (lenth-- ) 
    { 
       tmp += *str++; 
    
    } 
    return ((unsigned char)(-((char)tmp))); 
} 


void construct_ascii_frm ( unsigned char *dst_buf, unsigned char *src_buf, unsigned char lenth) 
{ 
     unsigned char lrc_tmp; 
      
     lrc_tmp = lrc( src_buf, lenth); 
     *(src_buf+lenth) = lrc_tmp; 
     lenth++; 
     *dst_buf = ':'; 
     rtutoascii( dst_buf,src_buf, lenth); 
     *(dst_buf + 2 * lenth+1) = 0x0d; 
     *(dst_buf + 2 * lenth+2) = 0x0a; 
} 


void construct_rtu_frm ( unsigned char *dst_buf,unsigned char *src_buf,unsigned char lenth) 
{ 
    unsigned short  crc_tmp; 
    crc_tmp = crc(src_buf, lenth); 
      
    *(src_buf+lenth) = crc_tmp >> 8 ; 
    *(src_buf+lenth+1) = crc_tmp & 0xff; 
    lenth++; 
    lenth++; 
  
    while ( lenth--) 
    { 
       *dst_buf = *src_buf; 
       dst_buf++; 
       src_buf++;         
    } 
} 

/* 
1 读取继电器状态 
发送： 
*/ 

int ascii_read_coil_status ( unsigned char board_adr, unsigned char *com_buf,int start_address,int lenth)  

{ 
    unsigned char tmp[256],tmp_lenth; 
    tmp[0] = board_adr; 
    tmp[1] = READ_COIL; 
    tmp[2] = HI(start_address); 
    tmp[3] = LOW(start_address); 
    tmp[4] = HI(lenth); 
    tmp[5] = LOW(lenth); 
    tmp_lenth = 6; 
    construct_ascii_frm (com_buf, tmp, tmp_lenth); 
    return 18; 
} 


int rtu_read_coil_status ( unsigned char board_adr,unsigned char *com_buf,int start_address,int lenth)  
{ 
    unsigned char tmp[256], tmp_lenth; 
     
    tmp[0] = board_adr; 
    tmp[1] = READ_COIL; 
    tmp[2] = HI(start_address); 
    tmp[3] = LOW(start_address); 
    tmp[4] = HI(lenth); 
    tmp[5] = LOW(lenth); 
    tmp_lenth = 6; 
    construct_rtu_frm ( com_buf, tmp, tmp_lenth); 
    return 8; 
} 

/* 
2 读取开关量输入 
发送： 
*/ 

int ascii_read_input_status ( unsigned char board_adr,unsigned char *com_buf,int start_address,int lenth)  
{ 
    unsigned char tmp[256], tmp_lenth; 
     
    tmp[0] = board_adr; 
    tmp[1] = READ_DI; 
    tmp[2] = HI(start_address); 
    tmp[3] = LOW(start_address); 
    tmp[4] = HI(lenth); 
    tmp[5] = LOW(lenth); 
    tmp_lenth = 6; 
    construct_ascii_frm ( com_buf, tmp, tmp_lenth); 
    return 18; 
} 


int rtu_read_input_status ( unsigned char board_adr,unsigned char *com_buf,int start_address,int lenth)  
{ 
    unsigned char tmp[256], tmp_lenth; 
     
    tmp[0] = board_adr; 
    tmp[1] = READ_DI; 
    tmp[2] = HI(start_address); 
    tmp[3] = LOW(start_address); 
    tmp[4] = HI(lenth); 
    tmp[5] = LOW(lenth); 
    tmp_lenth = 6; 
    construct_rtu_frm ( com_buf,tmp,tmp_lenth); 
    return 8; 
} 


/* 
3 读取保持寄存器 
发送： 
*/ 

int ascii_read_hldreg ( unsigned char board_adr,unsigned char *com_buf,int start_address,int lenth)  
{ 
    unsigned char tmp[256], tmp_lenth; 
     
    tmp[0] = board_adr; 
    tmp[1] = READ_HLD_REG; 
    tmp[2] = HI(start_address); 
    tmp[3] = LOW(start_address); 
    tmp[4] = HI(lenth); 
    tmp[5] = LOW(lenth); 
    tmp_lenth = 6; 
    construct_ascii_frm ( com_buf, tmp, tmp_lenth); 
    return 18; 
} 

int  rtu_read_hldreg ( unsigned char board_adr,unsigned char *com_buf,int start_address,int lenth)  
{ 
    unsigned char tmp[256], tmp_lenth; 
     
    tmp[0] = board_adr;