Once you've plugged in your modem and know which serial port it's
on you're ready to try using it. Before you try to get the Internet
on it or have people call in to you, you could first try something
simpler like dialing out to some number to see if your modem is
working OK. Find a phone number that is connected to a modem. If you
don't know what number to call, ask at computer stores for such phone
numbers of bulletin boards, etc. or see if a local library has a phone
number for their on-line catalog.
Then make sure you are ready to phone. Do you know what serial port
(such as ttyS2) your modem is on? You should have found this out when
you io-irq configured your serial ports. Have you decided what speed
you are going to use for this port? See
Speed Table for a quick selection or
What Speed Should I Use for more details. If you have no idea
what speed to set, just set it a few times faster than the advertised
speed of your modem. Also remember that if you see a menu where an
option is "hardware flow control" and/or "RTS/CTS" or the like, select
it. Is a live telephone cable plugged in to your modem? You may want
to connect the cable to a real telephone to make sure that it can
produce a dial tone.
Now you need to select a communication (dialing) program to use to
dial out. Dialing programs include: minicom, seyon (X-windows), and
kermit. See section
Communications Programs
about some communications programs. Two examples are presented next:
Dialing Out with Minicom and
Dialing Out with Kermit
Minicom comes with most Linux distributions. To configure it you
should be the root user. Type "minicom -s" to configure. This will
take you directly to the configuration (set-up) menus. Alternatively
you could just run "minicom" and then type ^A to see the bottom status
line. This shows to type ^A Z for help (you've already typed the ^A
so just type z). From the help menu go to the Configuration menu.
Most of the options don't need to be set for just simply dialing out.
To configure you have to supply a few basic items: the name of the
serial port your modem is on such as /dev/ttyS2 and the speed such as
115200. These are set at the serial port menu. Go to it and set
them. Also (if possible) set hardware flow control (RTS/CTS). Then
save them. When typing in the speed, you should also see something
like "8N1" which you should leave alone. It means: 8-bit bytes, No
parity, 1 stop-bit appended to each byte. If you can't find the speed
you want, a lower speed will always work for a test. Exit (hit
return) when done and save the configuration as default (dfl) using
the menu. You may want to exit minicom and start it again so it can
now find the serial port and initialize the modem, or you could go to
help and tell minicom to initialize the modem.
Now you are ready to dial. But first at the main screen you get
after you first type "minicom" make sure there's a modem there by
typing AT and then hit the <enter> key. It should display OK.
If it doesn't something is wrong and there is no point of trying to
dial.
If you got the "OK" go back to help and select the dialing directory.
You may edit it and type in a phone number, etc. into the directory
and then select "dial" to dial it. Alternatively, you may just dial
manually (by selecting "manual" and then type the number at the
keyboard). If it doesn't work, carefully note any error messages and
try to figure out what went wrong.
You can find the latest version of kermit at http://www.columbia.edu/kermit/. For example, say your
modem was on ttyS3, and its speed was 115200 bps. You would
do the following:
linux# kermit
C-Kermit 6.0.192, 6 Sep 96, for Linux
Copyright (C) 1985, 1996,
Trustees of Columbia University in the City of New York.
Default file-transfer mode is BINARY
Type ? or HELP for help.
C-Kermit>set line /dev/ttyS3
C-Kermit>set carrier-watch off
C-Kermit>set speed 115200
/dev/ttyS3, 115200 bps
C-Kermit>c
Connecting to /dev/ttyS3, speed 115200.
The escape character is Ctrl-\ (ASCII 28, FS)
Type the escape character followed by C to get back,
or followed by ? to see other options.
ATE1Q0V1 ; you type this and then the Enter key
OK ; modem should respond with this
If your modem responds to AT commands, you can assume your modem
is working correctly on the Linux side. Now try calling another modem
by typing:
ATDT7654321
where 7654321 is a phone number. Use ATDP instead of ATDT if you have
a pulse line. If the call goes through, your modem is working.
To get back to the kermit prompt, hold down the Ctrl key, press
the backslash key, then let go of the Ctrl key, then press the C key:
Ctrl-\-C
(Back at linux)
C-Kermit>quit
linux#
This was just a test using the primitive "by-hand" dialing method.
The normal method is to let kermit do the dialing for you with
its built-in modem database and automatic dialing features, for example
using a US Robotics (USR) modem:
linux# kermit
C-Kermit 6.0.192, 6 Sep 1997, for Linux
Copyright (C) 1985, 1996,
Trustees of Columbia University in the City of New York.
Default file-transfer mode is BINARY
Type ? or HELP for help
C-Kermit>set modem type usr ; Select modem type
C-Kermit>set line /dev/ttyS3 ; Select communication device
C-Kermit>set speed 115200 ; Set the dialing speed
C-Kermit>dial 7654321 ; Dial
Number: 7654321
Device=/dev/ttyS3, modem=usr, speed=115200
Call completed.<BEEP>
Connecting to /dev/ttyS3, speed 115200
The escape character is Ctrl-\ (ASCII 28, FS).
Type the escape character followed by C to get back,
or followed by ? to see other options.
Welcome to ...
login:
