#include <modbus.h>#include <fcntl.h>/************************************************************************************		Mb_test_crc : check the crc of a packet*************************************************************************************input :-------trame  : packet with is crcn      : lenght of the packet without tht crc                              ^^^^^^^answer :--------1 = crc fealure0 = crc ok************************************************************************************/int Mb_test_crc(byte trame[],int n){	unsigned int crc,i,j,carry_flag,a;	crc=0xffff;	for (i=0;i<n;i++)	{		crc=crc^trame[i];		for (j=0;j<8;j++)		{			a=crc;			carry_flag=a&0x0001;			crc=crc>>1;			if (carry_flag==1)				crc=crc^0xa001;		}	}   if (Mb_verbose)      printf("test crc %0x %0x\n",(crc&255),(crc>>8));	if ((trame[n+1]!=(crc>>8)) || (trame[n]!=(crc&255)))      return 1;   else      return 0;}/************************************************************************************		Mb_calcul_crc : compute the crc of a packet and put it at the end*************************************************************************************input :-------trame  : packet with is crcn      : lenght of the packet without tht crc                              ^^^^^^^answer :--------crc************************************************************************************/int Mb_calcul_crc(byte trame[],int n){	unsigned int crc,i,j,carry_flag,a;	crc=0xffff;	for (i=0;i<n;i++)	{		crc=crc^trame[i];		for (j=0;j<8;j++)		{			a=crc;			carry_flag=a&0x0001;			crc=crc>>1;			if (carry_flag==1)				crc=crc^0xa001;		}	}	trame[n+1]=crc>>8;	trame[n]=crc&255;	return crc;}/************************************************************************************		Mb_close_device : Close the device*************************************************************************************input :-------Mb_device : device descriptorno output************************************************************************************/void Mb_close_device(int Mb_device){  if (tcsetattr (Mb_device,TCSANOW,&saved_tty_parameters) < 0)    perror("Can't restore terminal parameters ");  close(Mb_device);}/************************************************************************************		Mb_open_device : open the device*************************************************************************************input :-------Mbc_port   : string with the device to open (/dev/ttyS0, /dev/ttyS1,...)Mbc_speed  : speed (baudrate)Mbc_parity : 0=don't use parity, 1=use parity EVEN, -1 use parity ODDMbc_bit_l  : number of data bits : 7 or 8 	USE EVERY TIME 8 DATA BITSMbc_bit_s  : number of stop bits : 1 or 2    ^^^^^^^^^^^^^^^^^^^^^^^^^^answer  :---------device descriptor************************************************************************************/int Mb_open_device(char Mbc_port[20], int Mbc_speed, int Mbc_parity, int Mbc_bit_l, int Mbc_bit_s){  int fd;  /* open port */  fd = open(Mbc_port,O_RDWR | O_NOCTTY | O_NONBLOCK | O_NDELAY) ;  if(fd<0)  {    perror("Open device failure\n") ;    exit(-1) ;  }  /* save olds settings port */  if (tcgetattr (fd,&saved_tty_parameters) < 0)  {    perror("Can't get terminal parameters ");    return -1 ;  }  /* settings port */  bzero(&Mb_tio,sizeof(&Mb_tio));  switch (Mbc_speed)  {     case 0:        Mb_tio.c_cflag = B0;        break;     case 50:        Mb_tio.c_cflag = B50;        break;     case 75:        Mb_tio.c_cflag = B75;        break;     case 110:        Mb_tio.c_cflag = B110;        break;     case 134:        Mb_tio.c_cflag = B134;        break;     case 150:        Mb_tio.c_cflag = B150;        break;     case 200:        Mb_tio.c_cflag = B200;        break;     case 300:        Mb_tio.c_cflag = B300;        break;     case 600:        Mb_tio.c_cflag = B600;        break;     case 1200:        Mb_tio.c_cflag = B1200;        break;     case 1800:        Mb_tio.c_cflag = B1800;        break;     case 2400:        Mb_tio.c_cflag = B2400;        break;     case 4800:        Mb_tio.c_cflag = B4800;        break;     case 9600:        Mb_tio.c_cflag = B9600;        break;     case 19200:        Mb_tio.c_cflag = B19200;        break;     case 38400:        Mb_tio.c_cflag = B38400;        break;     case 57600:        Mb_tio.c_cflag = B57600;        break;     case 115200:        Mb_tio.c_cflag = B115200;        break;     case 230400:        Mb_tio.c_cflag = B230400;        break;     default:        Mb_tio.c_cflag = B9600;  }  switch (Mbc_bit_l)  {     case 7:        Mb_tio.c_cflag = Mb_tio.c_cflag | CS7;        break;     case 8:     default:        Mb_tio.c_cflag = Mb_tio.c_cflag | CS8;        break;  }  switch (Mbc_parity)  {     case 1:        Mb_tio.c_cflag = Mb_tio.c_cflag | PARENB;        Mb_tio.c_iflag = ICRNL;        break;     case -1:        Mb_tio.c_cflag = Mb_tio.c_cflag | PARENB | PARODD;        Mb_tio.c_iflag = ICRNL;        break;     case 0:     default:        Mb_tio.c_iflag = IGNPAR | ICRNL;        break;  }  if (Mbc_bit_s==2)     Mb_tio.c_cflag = Mb_tio.c_cflag | CSTOPB;       Mb_tio.c_cflag = Mb_tio.c_cflag | CLOCAL | CREAD;  Mb_tio.c_oflag = 0;  Mb_tio.c_lflag = 0; /*ICANON;*/  Mb_tio.c_cc[VMIN]=1;  Mb_tio.c_cc[VTIME]=0;  /* clean port */  tcflush(fd, TCIFLUSH);  fcntl(fd, F_SETFL, FASYNC);  /* activate the settings port */  if (tcsetattr(fd,TCSANOW,&Mb_tio) <0)  {    perror("Can't set terminal parameters ");    return -1 ;  }    /* clean I & O device */  tcflush(fd,TCIOFLUSH);     if (Mb_verbose)   {      printf("setting ok:\n");      printf("device        %s\n",Mbc_port);      printf("speed         %d\n",Mbc_speed);      printf("data bits     %d\n",Mbc_bit_l);      printf("stop bits     %d\n",Mbc_bit_s);      printf("parity        %d\n",Mbc_parity);   }   return fd ;}/************************************************************************************		Mb_rcv_print : print a characterThis function can be use with slave or master to print a character when it receive one*************************************************************************************input :-------c : characterno output************************************************************************************/void Mb_rcv_print(unsigned char c){   printf("-> receiving byte :0x%x %d \n",c,c);}/************************************************************************************		Mb_snd_print : print a characterThis function can be use with slave or master to print a character when it send one*************************************************************************************input :-------c : characterno output************************************************************************************/void Mb_snd_print(unsigned char c){   printf("<- sending byte :0x%x %d \n",c,c);}char *Mb_version(void){   return VERSION;}