Command Execution

The modem waits a nominal 125 ms after the <CR>terminates command entry before it begins executing the command line. This allows the DTE to send a <LF>after the command line. The modem echoes the <LF>and any other characters received during the 125 ms wait, but they are ignored.

An AT command line consists of one or more individual commands. The execution of the command line consists of the left-to-right execution of each command followed by the reporting of a result code for the entire line. (See Result Codes) The execution of each command in that line may include the following:

1. Taking some action

2. Changing a configuration,

3. Or reporting information text to the DTE.

(For more details, see Information Text.) Some commands may change nonvolatile information in the mode.

There are two special exceptions of the left-to-right execution of the commands in the command line: (1) if the execution of a command produces the ERROR result code, or (2) if the executed command cannot be followed by additional commands, then the remaining commands are ignored.

Command execution produces an ERROR result code if any of the following conditions occur:

1. command letter, prefix, or suffix is invalid in the current context (unless otherwise specified),

2. command qualifier (e.g., = or ?) is invalid in the current context,

3. command line is too long (see the D command).

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