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From: Telecom-Request%mit-mc@brl-bmd.UUCP (Telecom-Request@mit-mc)
Newsgroups: fa.telecom
Subject: TELECOM Digest   V4 #25
Message-ID: <804@brl-bmd.UUCP>
Date: Tue, 21-Feb-84 18:48:07 EST
Article-I.D.: brl-bmd.804
Posted: Tue Feb 21 18:48:07 1984
Date-Received: Wed, 22-Feb-84 04:40:57 EST
Lines: 59



TELECOM Digest          Wednesday, 22 Feb 1984     Volume 4 : Issue 25

Today's Topics:
                                Issue #23
                   Cure for Vadic Triple Modem Problem
            Statistical Multiplexors and inverse multiplexing
             does anyone care what is happening in the SW ?
                      Yugoslav telephone security.
                       Re: TELECOM Digest   V4 #24
----------------------------------------------------------------------

Date: 20 Feb 1984 2103-EST
From: Jon Solomon 
Subject: Issue #23


Due to a error on my part, there was no Issue #23. Sorry for any 
inconvenience.

                        --JSol

------------------------------

From: vortex!lauren at RAND-UNIX
Date: Mon, 20-Feb-84 00:39:48-PST
Sender: Lauren Weinstein 
Subject: Cure for Vadic Triple Modem Problem

So bunky, you say you got yourself a Racal-Vadic triple modem 
(3451-series) and you have some problems with it?  You say that
sometimes in auto-answer mode it seems to hang offhook, making it
impossible for any new calls to arrive?  You say that when this
happens it refuses to respond to DTR and only resets if you cycle the
power or fiddle with the mode toggle switch (if you have one, that
is)?  Is that what's bothering you, bunky?

WELLLLL!  Lift up your head and greet the sun, 'cause a solution does
exist -- and it doesn't even involve hydrochloric acid or jackhammers!

Seriously, though, many persons have reported problems with triple
modems getting into a strange wedged condition from which it is
difficult to escape.  Both manual dial and autodial triples have shown
this behavior, which is characterized by the modem being offhook,
sending a 212 carrier, and having both the HS and DSR lights lit.
Only cycling the power or performing a software reset (by flipping the
toggle switch between auto and manual on the autodial modems) will
clear this condition; the modem is oblivious to DTR.  After having
this occur repeatedly on the main Vortex dialup line, I started
harassing the engineers up at Racal.  Actually, they were quite
helpful, once they realized that I knew what I was talking about and
hadn't plugged the RJ-11C phone plug into an AC wall outlet!

After talking with three different engineers and having them duplicate

***Sender closed connection***

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