User's Manual

Table Of Contents
AT+i Command Set
AT+i Programmer‘s Manual Version 8.32 1-2
If a syntax error is found anywhere in a command line, the remainder of the line is
ignored and the I/ERROR result code returned.
An AT+i command is accepted by iChip once the previous command has been fully
executed, which is normally indicated by the return of an appropriate result code.
Due to the fact that iChip is intended for Machine-to-Machine applications, only limited
parsing is performed on AT+i commands it receives from the host. The following
restrictions apply:
When setting parameters to values larger than the 65535 limit, the values is accepted
as mudulo 65535.
The validity of input IP addresses is not checked.
Illegal numbers, for example, 0.5 or 1.5 are not checked for validity.
1.4 Escape Code Sequence
While the iChip is in Internet mode attending to Internet communications, it is possible to
break into the communications and abort the Internet mode in an orderly manner. This is
achieved by sending the iChip a sequence of three (+) ASCII characters (+++) after a half
second silence period. In response to this, the iChip:
Shuts down Internet communications.
Terminates data transmission to the host.
Performs a software reset.
Responds with an I/ERROR (056) message.
Returns to command mode.
A maximum delay of 10msec may elapse from the time the (+++) escape sequence is sent
until iChip cuts off transmission to the host. The interrupted Internet activity is not
completed. Nevertheless, this is considered to comprise a session. Thus, parameters set
with the (~) character are restored to their permanent value.
1.5 Socket Command Abort
While the iChip is in Internet mode, during a TCP or UDP socket operation, it is possible
to override iChip‘s normal timeout procedure and abort the current socket operation in an
orderly manner. This is achieved by sending the iChip a sequence of three ASCII (-)
characters (---) following a half second silence period. The socket commands to which
this applies are:
STCP, SUDP, SSND, and SFSH. When iChip detects the socket abort
command, it aborts the last socket command and returns an I/ERROR following the
STCP and SUDP commands, or I/OK during an SSND or SFSH command.
1.6 Flexible Host and Modem Interfaces
The flexible host and modem interfaces feature enables users to select the interface
through which iChip accepts AT+i commands from the host processor, as well as the
interface through which AT+i commands are sent to a dialup or cellular modem.
Available host interfaces are: