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AT Commands

AT command formats

+++ Escape sequence

The escape sequence allows the modem to exit data mode and enter online command mode. While in online command mode, you can communicate directly with your modem using AT commands. When you finish, you can return to data mode using the ATO command.

There must be a pause after you enter an escape sequence before any additional characters can be sent to the modem. The length of this pause is set by Escape Guard Time (S12). The pause prevents the modem from interpreting the escape sequence as data.

The value of the escape sequence character may be changed using register S2.

A/ Repeat last command

This command repeats the last command string entered. Do not precede this command with an AT prefix nor conclude it by pressing Enter.

A Answer command

This command instructs the modem to go off-hook and answer an incoming call.

Bn Communication standard setting

This command determines the communication standard— either CCITT or Bell.

NOTE: This command is only useful for matching the modem to slower modems. It is rarely used today.

B0 Selects CCITT V.22 mode when the modem is at 1200 bps.