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Chapter 4 - Manual Dial and Automatic Answer
4.3 Manual Call Origination
You can use the modem to both originate and answer calls. To originate calls in Asynchronous mode,
you will most likely use the modem's Command mode, and give the modem automatic dialing
commands (we will delay our discussion of the Command mode until Chapter 5). When using your
modem in Synchronous mode, the Command mode is disabled, so you must automatically dial your
calls with a telephone set. To use manual dialing, you first connect an ordinary telephone set (either
touch tone or rotary dial) to the modem's PHONE Jack, if you have not already done so. Next, set the
speed selection, (DIP-Switches #13 and #14), to the speed at which you wish to communicate.
These DIP-Switches are located on the side of the modem. (Refer to Chapter 9 for DIP-Switch
settings.) Your computer or terminal may be set for up to 115,200 bps (57,600 bps for 1432 models,
37,800 bps for 932 models).
When your telephone set is connected, you can use it to dial the modem you wish to call. Simply dial
the number, and then listen to the dialed modem's answer tone. When you hear it, press the Voice/
Data switch on the front of the modem down (to the Originate position). You don't have to hold it
down. Just "toggle it" (press it once and let it go). Once you press the switch, the tone you hear
should change to another pitch, or change into a rough-sounding scrambled noise. You then replace
the telephone handset in its cradle, and your data communications begins.
Note that the modem may call manually via the keyboard command ATD, or by pressing the Voice/
Data switch on the modem's front panel downward. To force the modem to automatically answer
calls, either type ATA, or press the Voice/Data switch on the modem's front panel upward.
4.4 Automatic Answering
The modem can be used as an automatic answering modem. No special modifications or settings are
required other than making sure that the Auto-Answer select switch is set to Auto-answer enabled
(DIP-Switch #5 UP).
The modem, when in its idle state, is set for Originate mode frequencies. An incoming ring signal
automatically switches the modem into Answer mode.
You can program the modem to answer a call after a certain number of rings using S-Register S0
(see Chapter 6). Refer to Section 4.10 for the handshaking procedures used by the modem when in
automatic answer mode.
In many originate-only applications, you may wish to disable the automatic answer capability of the
modem. If a telephone set is connected to the modem, you may wish to receive incoming calls in a
voice mode for normal voice conversation. If auto-answer is not disabled, all incoming calls are
answered by the modem, preventing voice communications. To disable automatic answer, place DIP-
Switch #5 to the DOWN (Disable Auto Answer) position (refer to Chapter 9).
Another way to disable automatic answer is to use S-Register S0 to configure the modem to answer
on the nth ring, where n equals zero (0). Another alternative is to have the modem answer after five
or six rings, which gives you time to answer it manually if you wish. (See Chapter 6 for S-Register
information.)