[comp.sys.dec] Which Modems for DEC-Hardware ??

weis@netmbx.UUCP (Dietmar Weis) (04/19/91)

Is there anyone out there, who is experienced with modems connected to
VAXen under VMS and Ultrix and RISC stations ?
( I really hope so, 'cos in Germany there ain't nobody ... ;-)

I need brand names and recommendations.

I 've **peinfully** fumbled for a long time now and have discovered, that
you can't use any modem. But why ?? Nobody could tell me, even no one
at DEC here in Germany.

What I've found out, is, in short, that DEC handles the RS232 interface
in a very specific way, namely DSR:

With DSR present it waits 30 seconds for CD **and** CTS; if not detected, it
disconnects. (Security, or what ???)

So now, I need modem types which can be configured to assert DSR when a ring
is detected.

NOBODY in Germany knows of DEC modems, such as df02, df03 etc., even DEC
doesn't know, but several manuals mention them.

Which modems are known to work ? I'm interested in V32 and V22bis with MNP5.

Thank your very much.

Dietmar
-----------------------------------------------------------------------------
weis@netmbx.UUCP         | Dietmar Weis         DONOP CONSULT GmbH
Voice: 030/884 28 54-0   |                      Uhlandstrasse 179/180
Fax:   030/882 55 29     |                      D - 1000 Berlin 12
-----------------------------------------------------------------------------
-- 
weis@netmbx.UUCP         | Dietmar Weis         DONOP CONSULT GmbH
Voice: 030/884 28 54-0   |                      Uhlandstrasse 179/180
Fax:   030/882 55 29     |                      D - 1000 Berlin 12

j_prigot@wrglex.uucp (04/23/91)

In article <2275@netmbx.UUCP>, weis@netmbx.UUCP (Dietmar Weis) writes:
> Is there anyone out there, who is experienced with modems connected to
> VAXen under VMS and Ultrix and RISC stations ?
> ( I really hope so, 'cos in Germany there ain't nobody ... ;-)
> 
> I need brand names and recommendations.
> 
> I 've **peinfully** fumbled for a long time now and have discovered, that
> you can't use any modem. But why ?? Nobody could tell me, even no one
> at DEC here in Germany.
> 
> What I've found out, is, in short, that DEC handles the RS232 interface
> in a very specific way, namely DSR:
> 
> With DSR present it waits 30 seconds for CD **and** CTS; if not detected, it
> disconnects. (Security, or what ???)
> 
> So now, I need modem types which can be configured to assert DSR when a ring
> is detected.
> 
> NOBODY in Germany knows of DEC modems, such as df02, df03 etc., even DEC
> doesn't know, but several manuals mention them.
> 
> Which modems are known to work ? I'm interested in V32 and V22bis with MNP5.
> 
> Thank your very much.
> 
> Dietmar
> -- 
> weis@netmbx.UUCP         | Dietmar Weis         DONOP CONSULT GmbH
> Voice: 030/884 28 54-0   |                      Uhlandstrasse 179/180
> Fax:   030/882 55 29     |                      D - 1000 Berlin 12

Based upon what I have seen, just about any modem should be configurable to
your needs. The modem should be set to hangup when DTR is not asserted,
present DSR when "off-hook", and CTS and CARRIER when it receives the carrier
from the other modem. 

Note: this is based upon a VAX 3400/VMS platform. The modem control sequence
may be different on a RISC/Ultrix platform.

Our plant in Maintal currently uses a Telebit T1000 modem from the Bundespost.
I know that they had previously used a "non-approved" V.22bis modem.

-- 
Jonathan M. Prigot      j_prigot@wrglex or ...!{drilex|think}!wrglex!j_prigot