dave@uunet.uu.net (Dave Axness) (12/09/90)
I recently installed an uninterruptable power supply that has an RS-232
interface. Several pins on RS-232 connector are assigned to indicate the
status of the UPS ( ex. AC power fail, battery low, etc. ). I'm trying to
write a program to monitor this so that I can force an automatic shutdown
when the battery starts to run out.
It seems like I should be able to use ioctl to accomplish this but have
had no luck so far. I'm using the ttya port on the back of a 3/60. I'm
still running SUNOS 3.5 if that's an issue. Here's a code fragment:
int tty_status
FILE *ip;
ip = fopen("/dev/ttya","rw");
ioctl ( ip, TIOCMODG, &tty_status );
printf ("ttys status = 0x%x\n", tty_status );
I've tried to change the state of pin 20 (DTR) be connecting it to pin 7
(GND) or pin 25 (-5V) but the value of tty_status is always 0. Am I
trying to do this the right way or am I missing something here. Any help
would be appreciated.
Dave Axness
Quantum Medical Systems, Inc.
Issaquah, WA
uunet!wor-mein!dave