Intel MD566X manual Online Command Mode Escape Codes, On, Hanging Up Hn, S10, Zn, &D2

56K V.92 Data, Fax, and Voice Chipset

3.6 Online 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. 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 data to
1	second	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.

3.7 Hanging 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’.

3.8 Modem-to-Modem Connection Data Rates

The data rates differ for each data mode selected. V.90 or V.92 is the default data mode depending on the firmware version. For non-V.90 connections the chipsets fall back to V.34 mode. The modem defaults to whatever mode is issued by the +MS=m command (see page 56). The supported modulation types are listed in Table 3-2 on page 33. This table includes all modulation types and the data rates for transmitting and receiving. In Data mode, the 56K chipsets can transmit up to 48,000 bps (V.92 mode) or 33,600 bps (V.90 mode) and receive up to 53,333bps. Note that the chipsets are capable of achieving 56,000 bps, but power limitations by the FCC limit actual speeds to 53,333 bps. The 56K receive data rates can be achieved only in connections with equipment-compatible ISPs (Internet Service Providers). In V.92 mode, the MD566X supports 3 new features: Quick Connect, Modem-on-Hold and Pulse Code Modulation (PCM) Upstream.

The Quick Connect (QC) feature reduces the time it takes to make a connection to your service provider. The modem retains information of the line conditions from your previous connection and uses this information to bypass parts of the training sequence. As a result, this provides faster connections. Normal V.90 connections take about 25-30 seconds. With V.92 Quick Connect, your connect times can be up to 50% faster.

28 Intel Confidential Programmer’s Guide