Configuring a Device for a Modem

Use this procedure to configure a RealPort 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.

The PortServer and RealPort should be properly installed, configured and functioning before proceeding.

Procedure

1. Connect a proper cable between the port and modem.

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. Disable both the modem and non-modem control ports. This can be done through sysadm. SCO UnixWare users can enable and disable ports through scoadmin>Hardware>Serial Manager.

5. Modify the file /usr/lib/uucp/Devices. Create an entry look like this:
   
   Direct term/a01m,M - 38400 direct_modem
   
   The device ttya01m used here is just an example.
   
   Comment out any ACU lines relating to this device until dial-in is working properly.
   
   An ACU line is necessary for correct operation of the modem in dial-out applications. Refer to the modem manual or to the modem manufacturer for the correct modem initialization string to use for your modem. Refer to the SCO Administration handbook for guidance on setting up an appropriate ACU entry that uses this initialization string.

6. Connect to the modem by entering this command at a Unix root prompt:
   
   cu -l /dev/term/a01m -s 38400
   
   It may be necessary to use a01s instead:
   
   cu -l /dev/term/a01s -s 38400

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

8. Depending on the modem, it may be necessary to enable auto-answer with this at command:
   
   ats0=1&w

9. Disconnect from the modem by entering tilde-period.
   
   ~.

10. Enable and configure the port using one of the these three methods:

    Method	Description
    Using pmadm	This method can be used in any SVR4-based Unix system.  Though effective, it is often tedious to use because the command used is complicated. See Configuring a Device with pmadm.
    Using the Serial Manager in SCO UnixWare	This method works only in SCO UnixWare. See General SCO UnixWare Device Configuration.
    Using sysadm	This procedure works only in SVR4 systems that have access to a utility called sysadm. See General SVR4 Device Configuration.