shawn@marilyn.UUCP (Shawn P. Stanley) (12/11/90)
I've noticed a problem with some modems that I don't know the cause of.
If someone could explain to me what's going on, perhaps I can solve the
problem.
I have written connection-handling software which begins the process of
waiting for a call/connect first by setting the serial port to the high
(2400) baud rate for the modem, then sends an "AT" sequence (these are
Hayes compatible modems) so that the modem knows the baud rate of the
serial port and can then answer with a CONNECT message at the serial
port's rate before switching to the caller's rate.
With two modems that I know of, a 2400-baud caller will find that the
answering modem connects at 1200 baud. 300 baud calls are fine; 1200
baud calls are fine. But 2400-baud calls become 1200-baud connects.
What could explain this behavior?
--
Shawn P. Stanley shawn@marilyn.marilyn.mn.org
tcnet!marilyn!shawn {rosevax,crash}!orbit!marilyn!shawndavid@bacchus.esa.oz.au (David Burren) (12/13/90)
In <125@marilyn.UUCP> shawn@marilyn.UUCP (Shawn P. Stanley) writes: >I have written connection-handling software which begins the process of >waiting for a call/connect first by setting the serial port to the high >(2400) baud rate for the modem, then sends an "AT" sequence (these are >Hayes compatible modems) so that the modem knows the baud rate of the >serial port and can then answer with a CONNECT message at the serial >port's rate before switching to the caller's rate. AAARRRGGGGHHHHHH!!!!! "baud rate"? Urgle. Your grammar is _shocking_. baud => signal change rate bps => bit rate "signal change rate rate"???? It's an easy mistake to make, but it's one of my pet flames, so please excuse me if I fly off the handle. In most cases where people use "baud rate" they'd be better off using "bit rate" as it's more correct in several ways. ("more correct"? sigh :-) >With two modems that I know of, a 2400-baud caller will find that the >answering modem connects at 1200 baud. 300 baud calls are fine; 1200 >baud calls are fine. But 2400-baud calls become 1200-baud connects. I don't have an answer, but I've noticed the same problems with some modems. A Maestro ZXR when calling a v.32 modem or a Maestro 24DO (v.22bis/MNP) connects at 1200 bps unless ATB8 is issued beforehand. >What could explain this behavior? I'd be interested in any responses you get. _____________________________________________________________________________ David Burren [Athos] Email: david@bacchus.esa.oz.au Software Development Engineer Phone: +61 3 819 4554 Expert Solutions Australia, Hawthorn, VIC
koch@motcid.UUCP (Clifton Koch) (12/15/90)
From article <863@bacchus.esa.oz.au>, by david@bacchus.esa.oz.au (David Burren):
-> In <125@marilyn.UUCP> shawn@marilyn.UUCP (Shawn P. Stanley) writes:
->
->>I have written connection-handling software which begins the process of
->>waiting for a call/connect first by setting the serial port to the high
->>(2400) baud rate for the modem, then sends an "AT" sequence (these are
->>Hayes compatible modems) so that the modem knows the baud rate of the
->>serial port and can then answer with a CONNECT message at the serial
->>port's rate before switching to the caller's rate.
->
-> AAARRRGGGGHHHHHH!!!!!
->
-> "baud rate"? Urgle. Your grammar is _shocking_.
-> baud => signal change rate
-> bps => bit rate
->
-> "signal change rate rate"????
->
-> It's an easy mistake to make, but it's one of my pet flames, so please
-> excuse me if I fly off the handle.
-> In most cases where people use "baud rate" they'd be better off using
-> "bit rate" as it's more correct in several ways. ("more correct"? sigh :-)
In the paragraph you quoted, the original author is correct. He is talking
about the serial link between the modem and computer, which is 2400 *baud*.
Bit rate would also be OK, as long as it's not confused with data rate.
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