Intel 537EX - Manual (Page 29)

536EX Chipset Developer’s Manual 29
Intel Confidential
Data Mode AT COMMANDS
3.4 Modem Identification Commands [In, +FMI, +FMR,
+FMM, +GMI, +GMM, +GMR, +GSN,
+FMFR?, +FMDL?, +FREV?]
The modem provides product identification AT commands that help determine the modem’s
manufacturer, model number, and product revision. To provide flexibility with older software
application programs, the modem supports several commands that can be used to request a single
item of identification (such as a modem model number).
Table 15 lists the commands used to
obtain product information (all identification commands are usable in data, fax, or voice mode).
Example:
ATI1 Causes the modem to send the modem’s name to the DTE.
Intel 536EP Response to the modem name request.
V.92 Modem
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
or ATDS=m 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):
• 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.
• 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:
Table 15. Product Identification Information
AT Commands
Product Information ATIn Command Data Mode Class 1 Fax Mode Legacy Modems
Modem Manufacturer ATI2 AT+GMI AT+FMI AT+FMFR?
Model ID ATI1 AT+GMM AT+FMM AT+FMDL?
Revision Number ATI4 AT+GMR AT+FMR AT+FREV?