Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!jarthur!arnold
From: arnold@jarthur.Claremont.EDU (Arnold de Leon)
Newsgroups: comp.dcom.modems
Subject: Re: TB 2500 query
Summary: resetting on carrier loss possible on TB
Keywords: carrier loss TB T2500 Trailblazer
Message-ID: <2460@jarthur.Claremont.EDU>
Date: 15 Oct 89 19:55:14 GMT
References: <4946@orca.WV.TEK.COM> <848@metaphor.Metaphor.COM> <4974@orca.WV.TEK.COM>
Reply-To: arnold@jarthur.claremont.edu (Arnold de Leon)
Organization: Harvey Mudd College, Claremont, CA
Lines: 29

In article <4974@orca.WV.TEK.COM> jeffg@orca.WV.TEK.COM (Jeff C. Glover) writes:
>[...]  Again, I want a reset on loss of carrier, not DTR.  The
>modem is on the far end of a chain of networks (ethernet to appletalk
>to RS232), and DTR just isn't available.
>
>It looks like it just isn't possible. [...]
>

It is possible.  First, you configure the TB to toggle DSR
when it losses carrier (S130=3, S47 > 0).  (Now for the kludge)
You need a special cable/connector that loops DSR to DTR on the
modem side.   Then, set S52=2 (reset on DTR toggle).

Note DSR will be on even if there is no carrier.  The modem
will still be able to auto answer and originate calls.  But the magic
happens when the modem senses carrier loss, DSR will drop for the 
time specified in S47 (in msecs.) and since DSR was looped back
to DTR, DTR will also get toggled.  

I've discovered that TBs can do just about anything.  The biggest
headache is figuring which knobs to turn!

>Jeff
>jeffg%loki.wv.tek.com@relay.cs.net
-- 

Arnold de Leon                       arnold@jarthur.claremont.edu
Computer Science Dept., HMC          uunet!jarthur!arnold
Claremont, CA 91711                  arnold@hmcvax.bitnet