Communication to an external modem with HAYES commands CODE problems...

Communication to an external modem with HAYES commands CODE problems...

Post by Julius Caesa » Thu, 28 Dec 2000 22:22:58


Ok, I'm new on linux C system programmation. I'd like to communicate
with my external modem (with AT's commands) with a simple software I
would have written.

I tried to write one, but it doesn't operate... I don't know what's the
problem, that's why I ask your help. Here is the code i've written. My
modem doesn't compose the AT command (in 'buff')

Thank you for your help!!



#include <stdio.h>
#include <termios.h>
#include <sys/types.h>
#include <fcntl.h>

#define BAUDRATE B57600
#define MODEMDEVICE "/dev/ttyS0"        /* COM1 */

int main ()
        int fd;
        struct termios oldtio,newtio;
        char buff[255]="ATDT0497063344\n";      /* Commande AT */

        fd=open (MODEMDEVICE, O_RDWR);  /* Ouverture du file descr. */
        if(fd < 0)

        tcgetattr(fd,&oldtio);          /* sauv. du termios prec. */    

        newtio.c_cflag= BAUDRATE | CS8 | CLOCAL;
        newtio.c_iflag= IGNBRK | IGNPAR;
        newtio.c_oflag= 0;
        newtio.c_lflag= ICANON;

        tcflush(fd, TCIFLUSH);
        tcsetattr(fd, TCSANOW, &newtio);        /* nouv. termios */

        if (write(fd,buff,255)== -1)            /* Envoi au modem */
                fprintf(stdout,"Erreur du WRITE\n",255);

        tcsetattr(fd,TCSANOW,&oldtio);          /* Rcup. vieux termios




1. Newbie with a Hayes Optima 336 external modem

I recently "inherited" an external  Hayes Optima 336
V.34/V.FC modem with voice and fax capabilities (model 5345
US version 6.20). Unfortunately, I did not also "inherit"
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Guide. I'm gonna try to get it going on the weekend. In the
interim, I was wondering if anyone out there had any
experiences / tips / tricks I should be apprised of before
attempting this.


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