Path: utzoo!mnetor!uunet!husc6!mit-eddie!uw-beaver!tektronix!reed!percival!nerd
From: nerd@percival.UUCP (Michael Galassi)
Newsgroups: comp.dcom.modems
Subject: Getting a Trailblazer's ATtention
Message-ID: <1104@percival.UUCP>
Date: 19 Feb 88 16:08:46 GMT
References: <5445@elroy.Jpl.Nasa.Gov>References:
Reply-To: nerd@percival.UUCP (Michael Galassi)
Followup-To: comp.dcom.modems
Organization: Percy's UNIX, Portland, OR.
Lines: 33
Keywords: telebit trailblazer 19200
Summary: this is how I do it, want my dialer?

In article <5445@elroy.Jpl.Nasa.Gov> stevo@elroy.UUCP (Steve Groom) writes:

>...  The modem needs to be reset or otherwise kicked back
>into autobaud somehow before attempting the retry.

>In my testing, I never saw a case where the modem failed on the first
>try and then responded on the second or third.  If it failed on the
>first, it *always* failed on *all* subsequent retries, until something
>was done to the modem (reset or cycle DTR).  My solution was to cycle
>DTR between tries, with the modem configured to reset when it saw DTR
>drop (S52=2).

What I did to circumvent the autobauding problem was to always talk to
the modem at 19.2 KBpS, then I switch baudrate based on the result code
returned by the modem.  About a week ago I added code to togle dtr before
talking to the modem so I would be guaranteed that it is already at the
baudrate I expect it to be and all its internal buffers would be flushed.

I posted the dialer (along with a USR Courier dialer) about a month ago.
If anyone is using it and would like an updated version I will be happy
to send it along, just drop me a line.  If there is enough responce I
will re-post it.

Note: The way I have set things up works in an environment where I have
to disable dialin on the port everytime I want to dialout and then re-
enable dialin when I'm done, it works smoothly this way but there is no
reason for which it should not work on a dialin only line.

-michael
-- 
        Michael Galassi           | If my opinions happen to be the same as
...!tektronix!tessi!percival!nerd | my employer's it is ONLY a coincidence,
...!uunet!littlei!percival!nerd   | of cource coincidences DO happen.