Re: Modem changes behavior after Sarge Update
On Tuesday 21 February 2006 17:41, Mike McCarty wrote:
> Hal Vaughan wrote:
>
> [snip]
>
> > Now whenever a program ends, or if I kill a program (so it doesn't have
> > time to exit), I can tell by watching the modem that it hangs up
> > immediately (the carrier detect led goes off instantly, along with the
> > clear-to-send light). I'd think this was a Perl problem, since my
> > programs are in Perl, but it can't be a reset routine, since I lose the
> > connection even if I kill the program, without it being able to go
> > through closing down.
>
> This type of behavior is usually caused by "dropping DTR".
That's what it turned out to be. It's just not labelled DTR on the modem. It
took me a while to verify this because I was looking ONLY for DTR (when I get
stressed, I can get stuck in a linear mode and take things very literally).
I used Minicom for testing it and dialed in on my 2nd line to another
computer. What I can't get is why, when I killed minicom, the DTR line
dropped right away. Does kill look for lock files and release devices? When
I exited minicom (which resets the port), the DTR light (or rather the
equivalent led) stayed on. When I quit the program (which does not reset the
serial port), it stayed on, but when I killed minicom, the DTR led went off.
What does kill do that effects the DTR? While I've got things working, that
would help me for future reference.
I used AT&D0 to tell the modem to ignore the DTR line, and everything is
working as it did before I upgraded (first time I've ever seen an upgrade of
Debian Stable hose a system!).
Thanks, again, for your quick response. It's working now, which means I get
to sleep tonight and don't have to be at the computer at 6 am to make sure
it's working when it's time to connect to my data source.
Hal
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