atdialer is a configurable dialer program for modems. UUCP comes with a selection of dialers for popular modems, but to get the maximum performance out of some devices you may want to create a customized dialer. Alternatively, if you are using a non-standard modem you may have to create a dialer for it.
Dialer configuration files can also be created using the script /usr/lib/uucp/make.dialer. This script prompts for information on the commands recognized by the modem or dialer, then saves them in an appropriately-named file.
As shipped, there exist several atdialname symbolic links to atdialer for which configuration files exist in /usr/lib/uucp/default. The atdialer binary works out which configuration file to use by checking the name that was used to invoke it. It then looks for the configuration file atdialname in /usr/lib/uucp/default.
When cu(C), uucico(ADM), or getty(M) run on a given line, they read the file /usr/lib/uucp/Devices. This specifies the dialer to use for controlling a given modem. Using the configuration strings specified in its current configuration file, atdialer attempts to contact the modem on the specified tty at the specified speed, and dials the specified telephone number. It returns either an error string from the modem (for example, NO CARRIER or BUSY) or if successful, the speed of the connection (for example, 19200 for a 19,200-baud connection).
Note that a proper /etc/gettydefs file for the modem must exist before atdialer will work properly. The modem must use RTS/CTS flow control if UUCP is selected; /etc/inittab and /etc/conf/init.d/sio should be set up to permit this.
The -f option selects call discrimination and selection for modems that support this functionality. This sends the commands MDM_SETUP, MDM_SPEAKER, MDM_DSBLESC, MDM_DIALIN, and MDM_CDS to the modem. The atdialer will expect either the response RTC_DATA or RTC_FAX from the modem. If RTC_FAX is received, a FAX connection has been detected, and atdialer will exit with a value of RCE_FAXMODE. If RTC_DATA is received, atdialer sends MDM_ONLINE (if defined) to the modem, and then waits for RTC_CONNECT. When it receives RTC_CONNECT, atdialer will exit with a value of RCE_DATAMODE. If other strings are returned (such as ``ERROR''), atdialer will exit with a value of RCE_FAIL.
If the -h option is specified, the line is disconnected when the last process holding the line open either closes it or terminates. getty calls the dialer program with this option whenever it starts up on a line enabled in /etc/inittab and listed in /usr/lib/uucp/Devices with this dialer.
You should be prepared to enter the modem setup strings and (optionally) register settings: refer to your modem documentation for further information about suitable values.
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Parameter Default Description
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MDM_ATSPEED 0 Control delay in
milliseconds between
sending AT commands
MDM_ATTN This parameter is no
longer supported and is
ignored
MDM_CDS AT+FAA=1;+FCR=1 Select call
discrimination and
selection
MDM_DIALCMD ATDT Dial command
MDM_DIALIN ATS0=1 Answer after 1 ring
MDM_DSBLESC ATS2=128 Disable modem escape
MDM_ESCAPE +++ Escape to command mode
MDM_FAXBAUD 19200 Select speed of
19,200bps between DCE
and DTE
MDM_HANGUP ATQ0H0 Hangup
MDM_MODE DATA Answer mode DATA or AUTO
MDM_ONLINE Command to go online
after a DATA connection
has been established
MDM_OPTION Commands which enable
line speed to be varied
MDM_QUIET ATQ1 Inhibit sending of
result codes to DTE
MDM_RESET This parameter is no
longer supported and is
ignored
MDM_SETUP AT&F0 This parameter must be
supplied
MDM_SPEAKER ATM0 Speaker control command
RTC_BUSY BUSY Message to expect for
busy line
RTC_CONNECT Message to expect for
connection at any speed
RTC_DATA DATA Message to expect for
DATA connection
RTC_ERROR ERROR Message to expect on
command error
RTC_FAX FAX Message to expect for
FAX connection
RTC_NOANS NO ANSWER Message to expect for no
answer
RTC_NOCARR NO CARRIER Message to expect for no
carrier
RTC_NOTONE NO DIALTONE Message to expect for no
dialtone
RTC_OK OK Message to expect on
command success
RTC_speed Message to expect when
connection set to speed;
set to ``not used'' for
unused speeds
STTY -ortsflow stty settings; default
rtsflow ctsflow is to use hardware flow
control
MDM_OPTION allows you to set up special registers
on the modem. To enable these settings,
put an X or an x at the end of the phone number in a
Systems file entry. For example:
Setting any of the RTC_speed parameters is unnecessary for modern modems that can perform speed conversion. If hardware flow control is used between the computer and the modem, the modem can use the fastest speed that it can negotiate with the remote modem. In this case, set RTC_CONNECT to ``CONNECT''.
MDM_SETUP must be present and defined.
A ``*'' at the start of a line indicates a comment.
* Enable FAX/DATA detection: * MDM_MODE=AUTO MDM_SETUP=AT&F+FAA=1 * * NOTE: automatic FAX/DATA selection may not be available. * * Setup commands: * * &D2 Computer must raise DTR for modem to accept commands * &C1 Modem raises CD while a connection is present * &B1 Use fixed line speed between computer and modem * &R2 Use hardware flow control for received data * &H1 Use hardware flow control for transmitted data * MDM_SETUP=AT&FX4Q0&D2&C1&B1S0=1S2=043M0&R2&H1 * * Use fastest connection speed available; * atdialer sets the line speed between computer and modem. * RTC_CONNECT=CONNECT * * Use bidirectional hardware flow control. * STTY=-ortsfl rtsflow ctsflow
SCO OpenServer Release 5.0.6 -- 1 August 2000