At Command Set; Data And General Commands; Escape Sequence - US Robotics 56 K SOFTMODEM - COMMAND REFERENCE REV 1 Command Reference Manual

AT Command Set

Note:If a parameter value is not entered, then the 56K Softmodem assumes a parameter value of zero.

Data and General Commands

+++Escape Sequence

A/—Repeat Last Command
AT commands are issued to the modem to control the modem's operation and
software configuration. The basic command syntax is as follows:
• <command><parameter>.
The <command> is a combination of the attention prefix (AT) followed by the AT
command. The <parameter> is a string that represents a numeric decimal value.
Any command issued is acknowledged with a response in either text or numeric
values. These responses are known as result codes. The result codes are listed in
Table 5-1: Result Code Summary.
AT commands can only be entered while the modem is in command mode.
Command mode is entered under one of the following conditions:
After powerup, at the termination of a connection, or after the execution of a
command other than dial or answer.
Upon the receipt of the escape sequence (three consecutive characters matching
the contents of register S2) while in on-line mode.
Upon the on-to-off transition of DTR if &D1, &D2, or &D3 has been set.
An escape sequence allows the modem to exit data mode and enter on-line
command mode. While in on-line command mode, AT commands are sent directly
to the modem. Use the return to on-line data mode command (see "O<value>—
Return to On-Line Data Mode" on page 15) to return to data mode.
Place a pause before and after the escape sequence to prevent the modem from
interpreting the escape sequence as data. The length of the pause is set by
register S12 (see "S12—Escape Guard Time" on page 88), the escape guard
time. Register S2 (see "S2—AT Escape Character (User-Defined)" on page 86)
identifies the escape sequence character.
Use this command to repeat the last AT command. The modem repeats the
command currently in the command buffer. Do not use the AT prefix with this
command. Do not conclude the command with a terminating character such as
enter.
56K Softmodem
Command Reference
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