Intel MD566X - Manual (Page 27)

56K V.92 Data, Fax, and Voice Chipset
Programmer’s Guide Intel Confidential 27
ATI1 Causes the modem to send the modem’s firmware
version to the DTE.
CD08.55-612 (10/19/99)PARALLEL-SPEAKERPHONE 05-DSP PATCH.001.55
Firmware version that is the modem’s response to
the command.
3.5 Establishing a Modem Connection [A, D, DS = n, S0]
Data mode provides several methods for establishing a connection with a remote modem. For each
modem, a connection can be initiated manually or automatically in both answer and originate
modes. A manual-to-manual connection is useful when both modems (that are on-hook) are
connected to an off-hook telephone line. For example, if two people are talking on the telephone,
they can manually establish a modem connection without first hanging up. When establishing a
manual connection, one modem must be designated as the originating modem and the other as the
answering modem. Manual originate mode is initiated by sending an ATD to the DCE. Manual
answer mode is accomplished by sending an ATA to the DCE.
Automatic originate mode is initiated by sending an ATD <telephone number & dial modifiers>
or ATDS=n to the DCE. Automatic-answer mode is accomplished by setting S-register S0 to a
non-zero value. S1 keeps track of how many ring signals are detected. If the content of S0 is non-
zero and the number of ring signals (as defined by S0) are detected (that is, S1 = S0), then the DCE
goes off-hook and attempts to connect to the remote modem (with the following exceptions):
1) The time period between the ring signals is greater than 8 seconds, which causes
the S1 counter to reset and thus never reach the value for S0.
2) Caller ID is enabled and S0=1, the modem answers on the second ring signal
instead of the first ring signal. This happens because Caller ID puts a signal on the
telephone line between the first and second ring signal.
Example:
ATDT9,444-5555 Automatically dials the telephone number with
DTMF tones. After dialing a “9”, the comma (,)
causes the modem to pause two seconds before
dialing the rest of the telephone number.
modem 1: ATD; When establishing a manual-to-manual connection,
the designated originating
modem 2: ATA modem should receive the ATD command from its
DTE just before the designated answering modem
receives the ATA command from its DTE.
It is important that the time between the ATD and
ATA commands is less than 2 seconds.
AT-C1DT 123 Causes the modem to dial the telephone number 123
and immediately start sending a data calling tone.
Calling tone can then be detected by the remote voice
mail system. After detecting the calling tone, the
remote system can change to data mode and start the
data modem connection handshake.