From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bahadir Karuv Subject: Re: Newbie problem Date: Thu, 25 Apr 2002 13:37:07 -0400 Sender: linux-serial-owner@vger.kernel.org Message-ID: <3CC83EC3.B2ED7E48@bcacademies.bergen.org> References: <11E89240C407D311958800A0C9ACF7D13A77C6@EXCHANGE> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: List-Id: linux-serial@vger.kernel.org To: Ed Vance , linux-serial@vger.kernel.org Hi Ed, Thanks again for replying, I was wearing the mouse button, clicking New Msg icon. It is RS232, Dell Optiplex COM1. Best regards. Karuv Ed Vance wrote: > Hi Karuv, > > Is it not RS-232 interface? RS-485/422 2-wire will do this because the > > transmit and receive pairs are the same pair. > > Regards, > Ed > > ---------------------------------------------------------------- > Ed Vance edv@macrolink.com > Macrolink, Inc. 1500 N. Kellogg Dr Anaheim, CA 92807 > ---------------------------------------------------------------- > > -----Original Message----- > From: Bahadir Karuv [mailto:bahkar@bcacademies.bergen.org] > Sent: Thursday, April 25, 2002 10:12 AM > To: Ed Vance; linux-serial@vger.kernel.org > Subject: Re: Newbie problem > > Hi Ed, > > Thanks for the speedy response. I thought the same but the first > computer keeps getting whatever it is sending ("Hello") eventhough the > > serial cable is disconnected. The program I sent is running on the > first > computer. > > Thanks again and regards, > > Karuv > > Ed Vance wrote: > > > Hi, > > > > My guess is that the second computer has "echo" enabled so all > > characters > > received are echoed back to the other end. I see you turn echo off > in > > the > > program. I am assuming that the program is only running on the first > > > computer. > > > > Regards, > > Ed > > > > ---------------------------------------------------------------- > > Ed Vance edv@macrolink.com > > Macrolink, Inc. 1500 N. Kellogg Dr Anaheim, CA 92807 > > ---------------------------------------------------------------- > > > > -----Original Message----- > > From: Bahadir Karuv [mailto:bahkar@bcacademies.bergen.org] > > Sent: Thursday, April 25, 2002 8:59 AM > > To: linux-serial@vger.kernel.org > > Subject: Newbie problem > > > > Hello All, > > > > I am trying to have to computers communicate over the serial port. > > The program below is modified from "Serial Programming Guide for > Posix > > > > operating Systems" > > I am geting the following output when I send "Testing123" over the > > serial port from the second computer > > > > opened 3 > > just sent Hello > > got back - Hello > > just sent Hello > > got back - HelloTesting123 > > just sent Hello > > got back - Hello > > > > First computer is getting the string echoed back to itself after it > > sends "Hello". > > > > What am I doing wrong? > > > > Thanks and regards! > > > > > > > > #include > > #include > > #include > > #include > > #include > > > > int main(void) /* Serial port */ > > { > > time_t tsec; > > int fd; > > struct termios options; > > char buffer[255]; > > char *bufptr; > > int nbytes; > > char *message="Hello"; > > > > /* open the port */ > > fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY); > > //fcntl(fd, F_SETFL, FNDELAY); > > printf("opened %u\n",fd); > > /* options */ > > tcgetattr(fd, &options); > > options.c_cflag |= (CLOCAL | CREAD); > > options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); > > options.c_oflag &= ~OPOST; > > options.c_cc[VMIN] = 0; > > options.c_cc[VTIME] = 10; > > tcsetattr(fd, TCSANOW, &options); > > /* read characters into our string buffer until CR or NL */ > > while(1){ > > write(fd, message,strlen(message)); > > printf("just sent %s\n",message); > > tsec=time(NULL); > > while(time(NULL)-tsec<1); > > > > bufptr = buffer; > > buffer[0]='\0'; > > while ((nbytes = read(fd, bufptr, bufptr-buffer + > sizeof(buffer)-1)) > > > > > 0) > > { > > bufptr += nbytes; > > if (bufptr[-1] == '\n' || bufptr[-1] == '\r') > > { printf("break\n");break;} > > } > > if (buffer!=bufptr){ > > *(bufptr) = '\0'; > > printf("got back - %s\n",buffer); > > } > > } > > close(fd); > > } > > > > > > - > > To unsubscribe from this list: send the line "unsubscribe > > linux-serial" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > *** eSafe scanned this email for malicious content *** > > *** IMPORTANT: Do not open attachments from unrecognized senders > *** > > > *** eSafe scanned this email for malicious content *** > *** IMPORTANT: Do not open attachments from unrecognized senders *** >