Modem Operation A-5
Using the modem
To ensure that your ISDN modem is operating correctly, run your
communications software and make sure the ISDN modem is in
command mode. The modem does not need to be connected to a
phone line for these tests.
■Type AT and press the Return key. If you get the OK response,
you are in command mode and talking to your modem.
■Type AT\S and press the Return key. This command shows the
modem's active profile of command settings.
Resetting the modem
You can do a “soft reset” of the modem by typing in ATZ and
pressing the Return key. This recalls the stored parameters and
resets all modem registers. A “modem register” is a variable setting
which is entered into the modem's memory and defines a specific
modem setting. A “hard reset” is done by disconnecting the ISDN
modem, waiting a few seconds, and connecting it again.
Placing a call
To place a call, use the dial command (ATD). This command is
followed by a “dial string” which includes the telephone number. The
dial string can hold a maximum of 40 characters (not including the
two AT characters and spaces). Valid dial string characters are 0–9
and dial modifiers. The modem ignores invalid characters. A dial
string may also include modem commands, which must be added
after the AT and before the D command.