Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!hayes!tnixon
From: tnixon@hayes.uucp (Toby Nixon)
Newsgroups: comp.dcom.modems
Subject: Re: Telebits not talking to 2400 baud modems
Message-ID: <2173@hayes.uucp>
Date: 18 Oct 90 13:14:48 GMT
References: <3401@idunno.Princeton.EDU>
Organization: Hayes Microcomputer Products, Norcross, GA
Lines: 28

In article <3401@idunno.Princeton.EDU>, vnend@phoenix.Princeton.EDU
(D. W. James) writes: 

> Princeton has a bank of 4 Telebit T2500's to service its UUCP
> connections.  A few of those are 2400 baud no-name modems that 
> seem to be happy connecting to just about any other 2400 baud
> modem, but that die when they try to connect to the Telebits.
> ...
> protocals, then finally starts sending a 2400 carrier.  At that 
> point my modem starts to handshake, then hangs up abruptly.

It's possible that the modems on the host side have their S7 
registers set to a lower-than-normal value, providing only a limited 
time to establish a connection before hanging up.  It's also 
conceivable that the host itself allows only a certain amount of 
time between detecting an incoming call (RING) and DCD going high, 
or it drops DTR and gives up.  In either case, it's necessary to 
take action on the host side to alleviate the problem.

Have you tried forcing your T2500 to V.22bis/2400-only mode and 
connecting?  Does it work?

	-- Toby

Toby Nixon, Principal Engineer   | Voice:   +1-404-449-8791  AT&T:  !tnixon
Hayes Microcomputer Products Inc.| Fax:     +1-404-447-0178  CIS: 70271,404
P.O. Box 105203                  | UUCP: uunet!hayes!tnixon  MCI:  267-0805
Atlanta, Georgia  30348  USA     | Internet:      hayes!tnixon@uunet.uu.net