Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!apple!netcom!gandrews
From: gandrews@netcom.COM (Greg Andrews)
Newsgroups: comp.dcom.modems
Subject: Re: Will T2500 cycle all speeds if S50=3?
Summary: No.  S50=0, S92=1 is about the most you can do.
Message-ID: <1991Mar19.191701.16758@netcom.COM>
Date: 19 Mar 91 19:17:01 GMT
References: <1991Mar18.143749.1250@crom2.uucp>
Organization: Netcom - Online Communication Services  UNIX System {408 241-9760 guest}
Lines: 47

In article <1991Mar18.143749.1250@crom2.uucp> jim@crom2.uucp (James P. H. Fuller) writes:
>
>     Because several of my local callers have old and/or dimwitted modems
>that get confused and can't connect if I set my T2500's S50 register to 0
>(automatic speed determination, with either PEP or V.32 tones first,
>depending on S92) I presently have S50=3.  That sends 2400bps tones first
>and the local folx are happy, but as I read the manual (it's not totally
>clear on this point -- or maybe it is but I just don't like what I'm read-
>ing...) the modem is ONLY going to cycle among 2400-1200-300bps and NEVER
>send PEP or V.32 tones.  Is this correct?  
>

Yes, that's correct.  Setting S50=6-1 limits the modem to that connection
speed or slower speeds (if any) when fallback is enabled with S94=1.

>
>Is there a register setting that will start with 2400bps tones but still 
>cycle through ALL the others and give a fast connect to somebody calling 
>in PEP or V.32 mode?
>

No, there isn't.  The best that you can do is to set S50=0, S92=1, and
perhaps adjust S93 to a smaller value.  S93 determines the length of the
"AC" tone used by V.32 modems, so be careful.  The more you reduce the
"AC" tone, the lower your chances for getting V.32 connects.

There are still come 1200 and 2400 modems out there that barf big time
on the V.32 "AC" tone.  There's very little you can do to the answer
modem to compensate for the calling modem in this case.  The caller
could keep their modem off-line during the V.32 tones, and kick it
on-line afterward, so the modem doesn't see the tone it can't handle.
Another possibility would be for the caller to increase the values of
S9 and S10 in their modem when they call.  Neither of these methods
is a sure-fire fix, but that's all I can come up with at the moment.

Another possibility would be to somehow set your system up to answer
2400-only at certain times of day (S50=3).  The rest of the time, it 
would allow all speeds (S50=0, perhaps with S92=1), and users of old
1200/2400 modems would have to take their chances during that time.

Hope this helps...

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|  Greg Andrews   |       UUCP: {apple,amdahl,claris}!netcom!gandrews    |
|                 |   Internet: gandrews@netcom.COM                      |
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