Configuring a Device for a Modem

Use this procedure to configure a Digi device for a Dial-in/Dial-out modem connection. Configuring a device 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 a serial cable between the port and modem. For more in formation on cables, see the PortServer Cable Guide.

  2. Set the port to dev=rp on the PortServer by entering this command at a PortServer root prompt:

    set port dev=rp ra=12

    This example sets PortServer port 12 to be a RealPort device.

    Note: If your PortServer firmware does not support the dev=rp option, use dev=prn instead.

  3. If you are using 8-pin RJ-45 cabling from the PortServer to the modem, set the port to altpin=on by entering this command at a PortServer root prompt:

    set port altpin=on ra=12

    This example sets altpin=on for port 12 of a PortServer.

  4. Power the modem on.

  5. Connect to the modem by entering this command at a command prompt

    cu -l /dev/device -s 38400

    where device is the name of the non modem control device for the port.

  6. Set the modem to answer after the first ring with this command:

    ats0=1

  7. Train the modem to the port speed with this command:

    at&w

  8. Enter any other desired modem commands.

  9. Terminate the connection to the modem with a tilde followed by a period:

    ~.

  10. To manually configure the port to use hardware flow control by inserting this command in a Linux startup file:

    ditty-rp rtspace ctspace /device

    where /device is the name of the Digi device. Insert the command in a startup file so it remains in effect after a reboot.

    Alternately, use a gettydef entry that uses hardware flow control (see the next step)

  11. Edit the /etc/inittab file and add a getty entry for the device. The getty name that configures your device can vary from system to system. The following example is only meant to serve as a guide.

    Example:

    An example of an mgetty modem script which is available both in RedHat and Debian is:

    T3:23:respawn: /sbin/mgetty -x0 -s 115200 ttyaa00

    Use your device name instead of ttyaa00.

  12. Enable the port for login by rebooting the system or by entering this command at your Linux command prompt:

    init q