[comp.dcom.modems] Avatex 2400 won't autobaud

sean@cadre.dsl.PITTSBURGH.EDU (Sean McLinden) (04/01/88)

HELP! I have a bunch of Avatex 2400 baud modems connected to DMF32
ports on a Vax 11/780. They seem to work fine in 2400 baud mode, but
as soon as the modem is connected by someone at 1200 baud, the answering
modem is forever at 1200, it NEVER, autobauds back up.

This is infuriating. If anyone knows of a fix for this?? Also, the newer
modems have a set of DIP switches on the bottom, but no explanation in
the manual. If you call customer support they will tell you what the
switches DON'T do, but not what they do do. Any clues?

Sean McLinden
Decision Systems Laboratory
University of Pittsburgh

grr@cbmvax.UUCP (George Robbins) (04/02/88)

In article <1108@cadre.dsl.PITTSBURGH.EDU> sean@cadre.dsl.PITTSBURGH.EDU (Sean McLinden) writes:
> HELP! I have a bunch of Avatex 2400 baud modems connected to DMF32
> ports on a Vax 11/780. They seem to work fine in 2400 baud mode, but
> as soon as the modem is connected by someone at 1200 baud, the answering
> modem is forever at 1200, it NEVER, autobauds back up.

You don't give enough information to really identify the problem.

If they are on a DMF-32, the DMF-32 only has modem control on the first
two ports.  The system has no way to tell when modems on the other ports
call in or disconnect, or force them to disconnect.  Put modems on a
DHU-11 DMZ-32 DH11/clone or DZ11 - each of these has some quirks, so
be warned.

Second, how are you doing "auto-bauding"?  Is this Ultrix, BSD 4.3 or
some other software?  Do you have a gettytab entry selected that does
baud selection when you hit break?  If so, hitting characters at one
baud rate will cause framing errors index to the next speed, but this
isn't very reliable and it may not cycle back to a lower speed.

There is another form of auto-baud that intreprets what character is
received when you type carriage return at a preset baud rate.  This
is ususally something you have to select explictly, but it doesn't
seem to work with Ultrix so I don't know much about it...

-- 
George Robbins - now working for,	uucp: {uunet|ihnp4|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)