User's Manual

Table Of Contents
AT+i Command Set
AT+i Programmer‘s Manual Version 8.32 1-1
1 AT+i Command Set
1.1 Scope
This manual describes Connect One‘s AT+i™ interface standard, protocol, and syntax for
the iChip CO2128.
1.2 AT+i Command Guidelines
AT+i commands are an extension to the basic AT command set. They are parsed and
acted upon by iChip.
iChip in dial-up mode only: When iChip is in COMMAND mode, basic AT commands
and raw data (not prefixed by AT+i) are transparently transferred to the underlying
modem Digital Communications Equipment (DCE), where they are serviced. When
transferring data transparently to the DCE, the hardware flow control signals (CTS, RTS,
DTR and DSR) are mirrored across the iChip, unless disabled by the FLW parameter. AT
and AT+i commands may be issued intermittently. During an Internet session, when
iChip is online, an AT command can be sent to the modem using the AT+iMCM
command.
The ASCII ISO 646 character set (CCITT T.50 International Alphabet 5, American
Standard Code for Information Interchange) is used for issuing commands and responses.
Only the low-order 7 bits of each character are used for commands and parameters; the
high-order bit is ignored. Uppercase characters are equivalent to lowercase ones.
1.3 AT+i Command Format
An AT+i command line is a string of characters sent from the host to the iChip while it is
in command state. The command line has a prefix, body, and terminator. Each command
must begin with the character sequence AT+i and terminated by a carriage return <CR>.
Commands can be entered either in uppercase or lowercase.
iChip in dialup mode only: Commands that do not begin with the AT+i prefix are
transferred to the underlying DCE, where they are parsed and acted upon. DCE responses
are transparently returned to the host.
The AT+i command body is restricted to printable ASCII characters (032126). The
command terminator is the ASCII <CR> character. The command line interpretation
begins upon receipt of the carriage return character. An exception to this rule are the
AT+iEMB, AT+iSSND, AT+iTBSN and AT+iFSND commands.
When ECHO is enabled, the <CR> character is echoed as a two-character sequence:
<CR><LF> (Carriage Return+Line Feed).
Characters within the AT+i command line are parsed as commands with associated
parameter values.
The iChip supports editing of command lines by recognizing a backspace character.
When ECHO is enabled, the iChip responds to receipt of a backspace by echoing a
backspace character, a space character, and another backspace. When ECHO is disabled,
backspace characters are treated as data characters without any further processing.