Appendix B: AT Command Set
AT Commands
AT commands are issued to the modem to control the modem’s operation and soft- ware configuration. AT commands are commonly entered from a terminal program such as HyperTerminal, and can only be entered while the modem is in command mode. To enter an AT command, type:
ATXn
where X is the AT command, and n is the specific value for that command. Press
ENTER.
Commands are acknowledged with either text or numeric value response known as a result code. In the case of multiple AT commands on the same command line, the commands are executed in the order they are received. Should execution of a com- mand result in an error, or a character not be recognized as a valid command, execu- tion is terminated, the remainder of the command line is ignored, and the ERROR result code is issued. If all commands execute correctly, only the result code associ- ated with the last command shall be issued, even though all have been executed.
In the following listing all commands and command values accepted by the modem are shown. Any entries other than those shown cause the ERROR result code.
+++Escape sequence
The escape sequence allows the modem to exit data mode and enter
A/ | Repeat Last Command |
This command repeats the last command string entered. Do not precede this com- mand with an AT prefix or conclude it by pressing Enter.
A | Answer Command |
This command instructs the modem to go
34