Intel 536EX manual 3.6Online Command Mode Escape Codes, On, 3.7Hanging Up Hn, S10, Zn, &D2

Data Mode AT COMMANDS

ATDT 9,444-5555Automatically 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

modem 2: ATA originating 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.

3.6Online Command Mode [Escape Codes, On]

After establishing a connection with a remote modem, the DTE sends the appropriate escape sequence to the DCE, which causes the DCE to enter the online command mode. The online command mode is used to send AT commands to the DCE while the DCE is still connected to the remote modem. The supported escape sequences are described in Section 3.10, “AT Escape Sequences” on page 38. To re-enter the online data mode, use the ATOn command.

Example:

1	second +++	Hayes Escape Sequence. Guard times (in which the DTE does not send
1	second	data to the DCE) of 1 second are needed before and after the three
		escape characters ‘+’.
+++AT<CR>		TIES (Time Independent Escape Sequence).
ATO		Causes the modem to re-enter online data mode.

3.7Hanging Up [Hn, S10, Zn, &D2]

A modem connection terminates when the modem hangs up or when the remote modem transmit carrier is off longer than the duration specified in S-register S10. To hang up, the DTE typically sends an escape code sequence that causes the DCE to enter online command mode. Upon receiving an ‘OK’ message, the DTE sends either ATH or ATZn to the DCE. When the AT&D2 command is used, the modem goes on-hook (hangs up) after an on-to-off transition of the DTR occurs.

Note: The ATZn command causes the DCE to hang up and re-initialize itself to the user profile specified by ‘n’.

3.8Modem-to-Modem Connection Data Rates

The data rates differ for each data mode selected. The 536EX chipsets either default to V.90 or V.92 mode depending on the driver version. For non-ISP connections, the chipsets fall back to V.34 mode. The modem defaults to whatever mode is issued by the +MS=m command (see the supported modulation types on Table 16 on page 35).

30 536EX Chipset Developer’s Manual

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