Debian ttyS0 чтение с rs232

#include <stdio.h>   /* Standard input/output definitions */
#include <string.h>  /* String function definitions */
#include <unistd.h>  /* UNIX standard function definitions */
#include <fcntl.h>   /* File control definitions */
#include <sys/ioctl.h>
#include <errno.h>   /* Error number definitions */
#include <termios.h> /* POSIX terminal control definitions */
#include <stdint.h>
#include <sys/select.h>

typedef uint8_t BYTE;
typedef uint16_t WORD;
typedef uint32_t DWORD;

struct termios options;

WORD CRC16 (const BYTE *nData, WORD wLength)
{
static const WORD wCRCTable[] = {
    0X0000, 0XC0C1, 0XC181, 0X0140, 0XC301, 0X03C0, 0X0280, 0XC241,
    0XC601, 0X06C0, 0X0780, 0XC741, 0X0500, 0XC5C1, 0XC481, 0X0440,
    0XCC01, 0X0CC0, 0X0D80, 0XCD41, 0X0F00, 0XCFC1, 0XCE81, 0X0E40,
    0X0A00, 0XCAC1, 0XCB81, 0X0B40, 0XC901, 0X09C0, 0X0880, 0XC841,
    0XD801, 0X18C0, 0X1980, 0XD941, 0X1B00, 0XDBC1, 0XDA81, 0X1A40,
       
    0X1E00, 0XDEC1, 0XDF81, 0X1F40, 0XDD01, 0X1DC0, 0X1C80, 0XDC41,
    0X1400, 0XD4C1, 0XD581, 0X1540, 0XD701, 0X17C0, 0X1680, 0XD641,
    0XD201, 0X12C0, 0X1380, 0XD341, 0X1100, 0XD1C1, 0XD081, 0X1040,
    0XF001, 0X30C0, 0X3180, 0XF141, 0X3300, 0XF3C1, 0XF281, 0X3240,
   0X3600, 0XF6C1, 0XF781, 0X3740, 0XF501, 0X35C0, 0X3480, 0XF441,
   0X3C00, 0XFCC1, 0XFD81, 0X3D40, 0XFF01, 0X3FC0, 0X3E80, 0XFE41,
   0XFA01, 0X3AC0, 0X3B80, 0XFB41, 0X3900, 0XF9C1, 0XF881, 0X3840,
   0X2800, 0XE8C1, 0XE981, 0X2940, 0XEB01, 0X2BC0, 0X2A80, 0XEA41,
       
   0XEE01, 0X2EC0, 0X2F80, 0XEF41, 0X2D00, 0XEDC1, 0XEC81, 0X2C40,
   0XE401, 0X24C0, 0X2580, 0XE541, 0X2700, 0XE7C1, 0XE681, 0X2640,
   0X2200, 0XE2C1, 0XE381, 0X2340, 0XE101, 0X21C0, 0X2080, 0XE041,
   0XA001, 0X60C0, 0X6180, 0XA141, 0X6300, 0XA3C1, 0XA281, 0X6240,
   0X6600, 0XA6C1, 0XA781, 0X6740, 0XA501, 0X65C0, 0X6480, 0XA441,
   0X6C00, 0XACC1, 0XAD81, 0X6D40, 0XAF01, 0X6FC0, 0X6E80, 0XAE41,
   0XAA01, 0X6AC0, 0X6B80, 0XAB41, 0X6900, 0XA9C1, 0XA881, 0X6840,
   0X7800, 0XB8C1, 0XB981, 0X7940, 0XBB01, 0X7BC0, 0X7A80, 0XBA41,
       
   0XBE01, 0X7EC0, 0X7F80, 0XBF41, 0X7D00, 0XBDC1, 0XBC81, 0X7C40,
   0XB401, 0X74C0, 0X7580, 0XB541, 0X7700, 0XB7C1, 0XB681, 0X7640,
   0X7200, 0XB2C1, 0XB381, 0X7340, 0XB101, 0X71C0, 0X7080, 0XB041,
   0X5000, 0X90C1, 0X9181, 0X5140, 0X9301, 0X53C0, 0X5280, 0X9241,
   0X9601, 0X56C0, 0X5780, 0X9741, 0X5500, 0X95C1, 0X9481, 0X5440,
   0X9C01, 0X5CC0, 0X5D80, 0X9D41, 0X5F00, 0X9FC1, 0X9E81, 0X5E40,
   0X5A00, 0X9AC1, 0X9B81, 0X5B40, 0X9901, 0X59C0, 0X5880, 0X9841,
   0X8801, 0X48C0, 0X4980, 0X8941, 0X4B00, 0X8BC1, 0X8A81, 0X4A40,
       
   0X4E00, 0X8EC1, 0X8F81, 0X4F40, 0X8D01, 0X4DC0, 0X4C80, 0X8C41,
   0X4400, 0X84C1, 0X8581, 0X4540, 0X8701, 0X47C0, 0X4680, 0X8641,
   0X8201, 0X42C0, 0X4380, 0X8341, 0X4100, 0X81C1, 0X8081, 0X4040 };
       
    BYTE nTemp;
   WORD wCRCWord = 0xFFFF;
       
   while (wLength--){
       nTemp = *nData++ ^ wCRCWord;
      wCRCWord >>= 8;
      wCRCWord  ^= wCRCTable[nTemp];
   }
   return wCRCWord;
                   
} // End: CRC16

int open_port(void)
{
    int fd; /* File descriptor for the port */

    struct termios options;

    /* открытие порта */
    fd = open("/dev/ttyS0",O_RDWR | O_NOCTTY | O_NDELAY);

    /* получение текущих опций */
    tcgetattr(fd, &options);

    bzero(&options, sizeof(options));
    /* установка неструктурированного ввода, 1-секундный таймаут */
   
    options.c_cflag = B9600 | CRTSCTS | CS8 | CLOCAL | CREAD;
    options.c_iflag = IGNPAR;
    options.c_oflag = 0;
    options.c_lflag = 0;
   
    options.c_cc[VTIME]  = 10;
    options.c_cc[VMIN] = 0;

    /* установка опций */
    tcflush(fd, TCIFLUSH);
    tcsetattr(fd, TCSANOW, &options);

   printf("set option\n");
   return (fd);
}


int main(void){
    BYTE *send;
    BYTE *readRS;

    int fd = open_port();
   
    send=new BYTE[8];
   send[0]=0x01;
   send[1]=0x03;
   send[2]=0x00;
   send[3]=0x00;
   send[4]=0x00;
   send[5]=0x0A;
   WORD crc16;
   crc16=CRC16(send,6);
   send[6]=crc16;
   send[7]=crc16>>8;   
   
   if (write(fd,send,8)<8){
        printf("не записали:(");
   }
   
//  sleep(1);
    fd_set rfds;
   struct timeval tv;
   int retval;
   
    FD_ZERO(&rfds);
    FD_SET(fd, &rfds);
   
    tv.tv_sec = 1;
    tv.tv_usec = 0;
   
    retval = select(fd, &rfds, NULL, NULL, &tv);
   
    if (retval){
        int srb;
        ioctl(fd, FIONREAD, &srb);
        readRS=new BYTE[srb];
       int rb=read(fd,readRS,srb);
        if (rb>=0){
            printf("read: %i\n",rb);
            for(int i=0;i<rb;i++){
            printf("0x%02X ",readRS);
        }
            printf("\n");
        }else{
            printf("ERROR: %u\n", errno);
            perror("not read: ");
        }
    }
     else{
        printf("TimeOut\n");
    }
    close(fd);
    return 0;
}

sleep(1);
/*  fd_set rfds;
   struct timeval tv;
   int retval;
   
    FD_ZERO(&rfds);
    FD_SET(fd, &rfds);
   
    tv.tv_sec = 1;
    tv.tv_usec = 0;
   
    retval = select(fd, &rfds, NULL, NULL, &tv);
   
    if (retval){*/
        int srb;
        ioctl(fd, FIONREAD, &srb);
        readRS=new BYTE[srb];
       int rb=read(fd,readRS,srb);
        if (rb>=0){
            printf("read: %i\n",rb);
            for(int i=0;i<rb;i++){
            printf("0x%02X ",readRS);
        }
            printf("\n");
        }else{
            printf("ERROR: %u\n", errno);
            perror("not read: ");
        }
/*  }
     else{
        printf("TimeOut\n");
    }*/
    close(fd);
    return 0;