Using the Phone Out Port 2-17

Placing Analog Modem Calls

To place a call from your PC or Macintosh using the optional
V.32bis 14.4 Kbps internal analog fax modem (included with
models 3C872 and 3C877), use the AT command ATDT (for
connection to an analog modem using touch-tone dialing) or
ATDP (for connection to an analog modem using pulse dialing).

Using Communications Software to Place Calls

If you are using standard communications software, select a
Hayes-compatible modem configuration and dial out
through the 3Com Impact digital modem. Refer to your
communications software documentation for more details.

Receiving Data Calls

Incoming circuit-switched data calls from other
3Com Impact digital modems or from ISDN devices and
Sw56 equipment may be received by the digital modem.
If auto answer is disabled (the default) in register S0, a RING
message is delivered to the Computer port upon reception of
an incoming data call to the digital modem. The command AT
A answers the incoming data call. A CONNECT message is then
delivered to the Computer port upon successful connection.
If auto answer is enabled, the call is automatically answered
and a CONNECT message, indicating the speed of the
connection, is delivered to the Computer port.
Using the Phone Out Port
If you have analog touch-tone telephones, answering
machines, fax machines, external analog modems, or other
analog telephone devices, connect them to the 3Com Impact
digital modem’s RJ-11 modular jack labeled Phone Out on
the digital modem’s back panel (see Figure 2-1).
The 3Com Impact digital modem does not support pulse
dialing (rotary) telephones.