Configuring a Device for a Modem

Use this procedure to configure a Digi serial port for a Dial-in/Dial-out modem connection. Configuring a port for a modem requires familiarity with both the operating system and the modem being used. While the following procedure is sufficient for most cases, it may be necessary to take additional steps to properly configure your modem or to set up the operating system for a specific application.

Procedure

  1. Connect the modem to the Digi port.

  2. Turn the modem on.

  3. Access a root prompt on the AIX system.

  4. Add an entry for the device in the file /usr/lib/uucp/Devices. The following example allows a connection of 38400 baud to the device:

    Direct tty3 - 38400 direct

  5. Change the device ownership and group using these two commands:

    chown uucp /dev/tty#

    chgrp uucp /dev/tty#

    where # is the port number.

  6. Make sure the device is disabled with this command:

    pdisable tty#

    This command is not needed if the port is set to share (bidirectional).

  7. Enter this cu command to connect to the modem:

    cu -ml /dev/device -s 38400

    where device is the name of the TTY device. The modem should respond with an AT prompt.

  8. Train the modem to the port speed by entering this command at the AT prompt:

    at&w

  9. Terminate the connection by entering a tilde followed by a period followed by the Enter key at the AT prompt:

    ~. <Enter>

  10. Enter smit by entering this command at an AIX command prompt:

    smit tty

  11. Choose <Change/Show Characteristics of a TTY>.

  12. Select the tty device. This is an example of a listed device:

    tty7 Available 00-00-04-02 Asynchronous Terminal

    In this example, the first 00 is the bus number. The second 00 is the slot number. The number 04 is the sa or dm device number. The number 02 is the port number.

  13. Set Enable LOGIN to share.

  14. Set BAUD rate to the modem's highest configurable baud rate.

  15. Set PARITY, BITS per character, and number of STOP BITS to match the settings of the modem.

  16. Set FLOW CONTROL to be used to match the flow control used by the modem.