AT+i Programmer's Manual - SE Spezial-Electronic AG

SerialNET Theory of Operation
If the iChip is online at the time this command is issued, it closes the Internet session in
an orderly manner. This includes closing all open sockets and disconnecting from the ISP
in a modem environment.
When iChip boots up in SerialNET mode, it sets the host serial channel to the fixed baud
rate and serial interface parameters defined in the SNSI parameter. iChip in LAN mode
opens the SerialNET listening socket (if it is defined in the LPRT parameter) and, if
defined, launches the web server.
In an iChip dial-up environment, the modem is polled for the RING string. If the ringresponse
destination e-mail parameter (RRMA) or ring-response server parameter
(RRSV) contain values, iChip waits for the RING strings to subside and connects to the
Internet. Once online, it sends an e-mail to the RRMA address (if defined) and/or
establishes a socket to the address in RRSV (if defined). The transmission contains the
dynamic IP address received from the ISP and its listening port, on which iChip has an
open listening socket, ready to serve the remote client.
iChip goes offline if one of the following events occurs:
The remote peer closes the SerialNET socket.
The IATO parameter is defined and times out.
The terminating string defined in the DSTR parameter is received.
When the optional (!) (Auto-Link mode) flag is specified, iChip immediately goes online
in response to the AT+i!SNMD command, opens the SerialNET listening socket (if it is
defined in the LPRT parameter) or attempts to establish a socket to an HSRn address (if
any HSRn is defined and LPRT is not). In this case, if one of the terminating events
occurs, iChip does not go offline. Rather, the SerialNET socket is closed while iChip
stays online and opens the listening or active socket again, after waiting the SNRD delay.
When the optional (@) (Deferred Connection mode) flag is specified, iChip immediately
goes online in response to the AT+I@SNMD command. It opens the SerialNET listening
socket (if it is defined in the LPRT parameter) but does not attempt to establish a socket
to the HSRV address if it is defined. In this case, if one of the terminating events occurs,
iChip does not go offline. Rather, the SerialNET socket is closed while iChip stays online
and opens the listening socket again, after waiting the SNRD delay.
iChip exits SerialNET mode when one of the Escape procedures is activated.