C.3. Configure modem to ignore DTR and assert DCD

We will be doing a fair about of rebooting and having this hang up the modem is annoying, so modify the modem's configuration to ignore Data Terminal Ready. Use the AT&D0 to ignore the status of DTR.

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.