Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 124)

Chapter 7
Using the Serial Ports
7-16
/*** Report that watchdog timed out. All characters not sent in time ***/
if (watchdog == -1)
{
if (tmp_count > 0){
if ((status = read(path, tmp_buff, tmp_count)) == -1)
{
fprintf(stderr, “**** ERROR flushing input buffer ***\n”);
return(-1);
}
}
fprintf(stderr, “**** ERROR transmitting all characters - timeout ***\n”);
if (tmp_count != sent
fprintf(stderr, “**** ERROR flushing buffer not equal to characters sent ***\n”);
return(-1);
}
/*** Disable the transmitter ***/
if ((status = _ss_enrts(path)) == -1)
{
fprintf(stderr, “**** ERROR turning off the transmitter ***\n”);
return(-1);
}
/*** Flush the echo from the input buffer ***/
if ((status = read(path, tmp_buff, tmp_count)) == -1)
{
fprintf(stderr, “**** ERROR flushing input buffer ***\n”);
return(-1);
}
return(sent); /* Return the number of bytes sent */
} /* End of function */
#include
main(argc, argv)
int argc;
char *argv[];
{
int status;
int x=5;
int time=0;
int path;
char output[20];
char input[25];
int timeout;
strcpy(output, “abcdefghijklmnopq”);
x = atoi(argv[2]);
timeout = atoi(argv[3]);
path = open (argv[1], (S_IREAD | S_IWRITE));
init_485(path);
while(x--){
write_485(path, output, 17);
read_485(path, input, 22, timeout);
printf (“Received --> %s\n”, input);
tsleep(5);
}
}