raisch@control.com (Robert Raisch) (12/04/90)
I have a BIG problem.
Scenerio:
Sun Sparcstation 1+ (Sun/OS 4.1) is connected to an
asynch device on /dev/ttyb at 9600bps 8N1.
The asynch device understands simple ascii commands,
like: PT /* Get controllers attention */
O3=1 /* Turn Digital Output # 3 on. */
The only strangeness here is that the controller/asynch
device uses '\r' to end lines.
I have so far been able to talk to this device via tip,
(at 9600bps 8N1), and desperately need to talk to it in a
program. Nothing I do seems to allow me to talk to the device.
Most Recent Hack to Solve Problem:
I ran Tip in one window, and in another, as root,
I opened the tty (readonly), and read the termios struct and
the modem control lines.
I then set the termios and modem lines VERBATUM from what
tip seems to set them to.
Still no go! What am I missing?
/********************BEGIN EXAMPLE CODE*********************/
#include <stdio.h>
#include <fcntl.h>
#include <termio.h>
#include <sys/ttycom.h>
#define MAXBUF 1024
main( argc, argv)
int argc; char **argv;
{
int i;
int fd;
int flags;
char buf[ 1024];
struct termios Orig, Term;
if( (fd = fopen( "/dev/ttyb", O_RDWR)) < 3) exit( -1);
ioctl( fd, TCGETS, &Orig);
Term = Orig;
Term.c_iflag = 0x1420; /* From tip, (IXON | IXOFF | ISTRIP)
Term.c_oflag = 0;
Term.c_cflag = 0x4bd; /* From tip, (B9600 | HUPCL | CREAD | CS8) */
Term.c_lflag = 0;
Term.c_cc[VMIN] = 1; /* From tip, the only difference. (VMIN) */
Term.c_cc[VTIME] = 0;
ioctl( fd, TCSETS, &Term); /*** Set the new modes. ***/
flags = 0x66; /* From tip, (CD | CTS | RTS | DTR ) */
ioctl( fd, TIOCMSET, &flags); /*** Set the modem control lines ***/
strcpy( buf, "\n\n\n\nPT\n"); /*** Get the device's attention ***/
printf("Write(%d)\n", toCntrlr( fd, buf));
strcpy( buf, "\n\n\nO3=1\n"); /*** Turn Digital Output #3 on. ***/
printf("Write(%d)\n", toCntrlr( fd, buf));
ioctl( fd, TCFLSH, 2);
ioctl( fd, TCSETS, &Orig); /*** Back to the way we found it. ***/
flags = 0; /* Tip seems to do this when he exits, so what the hell. */
ioctl( fd, TIOCMSET, &flags);
close( fd);
}
toCntrlr( fd, str)
char *str;
{
return( write( fd, str, strlen( str)));
}
/********************END OF EXAMPLE**************************/
(NOTE: The writes return the proper number of characers each time.)
Query:
What am I missing here?
Is this the least documented and most confusing
of all of Unix? Or is it just me? <weak smile>
thanks for any help. -RR