C.3. Configure modem to ignore DTR and assert
DCD
The computer reboots a few times during the upgrade. These
reboots hang up the modem. Having to dial in a number of times
during the upgrade can become annoying. Altering the modem's
configuration to ignore Data Terminal Ready will cause the modem
not to hang up when the computer is rebooted. To ignore
DTR send the command
AT&D0 to the modem.
We may also wish to disconnect during the install to reduce
transmission charges. Configuring the modem to hold Data Carrier
Detect on will prevent any disconnection and reconnection from
being apparent to the installer. Use the command
AT&C0 to always hold DCD
high.
Apply these changes using the procedure in Section 12.3, retaining all of the other
AT commands.