Configuring automated modems

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Users can customize their modems manually or use the cu utility with its associated files to create an automated modem configuration script.

  • UUCP must be installed on the system. Use the lslpp -f | grep bos.net.UUCP command to verify installation.
  • A modem must be attached to the system and powered on.
  • The modem AT command string must already exist (for example, at&f&c1&d3). Users should not attempt automated modem configuration until the command string has first been tried manually using the cu command.
  • Root user authority is needed to change the appropriate files.

The following example shows how to automatically configure a Telebit T3000 modem attached to tty0.

  1. Edit the /etc/uucp/Systems file.
  2. Add the following line at the end of the file. The entry should begin in the leftmost column of the file. 
    telebit Nvr TELEPROG 19200
  3. Save and exit the file.
  4. Edit the /etc/uucp/Devices file.
  5. Add the following line at the end of the file. The entry should begin in the leftmost column of the file. 
    TELEPROG tty0 - 19200 TelebitProgram
  6. Save and exit the file.
  7. Edit the /etc/uucp/Dialers file.
  8. Add the following lines at the end of the file.
    The entries should begin in the leftmost column of the file.
    Note: The following four lines should be made into one long line: 
    TelebitProgram  =,-,    "" \dAT&F\r\c OK         
ats0=1s2=255s7=60s11=50s41=2s45=255s51=252s63=1s58=2s64=1\r\c OK  
ATs69=2s105=0s111=30s255=0M0&C1Q2&D3&Q0&R3&S1&T5\r\c OK 
ATE0X12&W\r\c OK
  9. Save and exit the file.
  10. To begin the automated configuration, type the following command: 
    cu -d telebit

    The command will fail because you are not connecting to a system. Watch the debug output of the command to see that ATE0X12&W is sent to the modem and that an OK is received. If so, then the modem has been successfully programmed.

Problems can arise because of incorrect values placed in the Dialers file or because of the modem's existing configuration. If this occurs, try programming the modem manually and enter the dialers strings (in step 8) one by one.