Technical information

Chapter 2: AT+i Commands Reference
May 31, 2008 AT+i Commands Reference Manual 2-19
SerialNET Mode Initiation
+iSNMD - Activate SerialNET Mode
Syntax: AT+i[! | @]SNMD
Activates SerialNET mode. Instead of using the optional (!) and (@) flags,
you can use the following syntax:
AT+iSNMD=1 is equivalent to AT+iSNMD
AT+iSNMD=2 is equivalent to AT+i!SNMD
AT+iSNMD=3 is equivalent to AT+i@SNMD
AT+iSNMD=4 causes W24 to enter SerialNET over TELNET mode
Command Options:
AT+i !S NM D
-or-
AT+iSNMD=2
Optional Auto-Link mode. When this flag is specified, W24 immediately
goes online when activating SerialNET mode (even when serial data has not
yet arrived). If the LPRT (Listening Port) parameter is defined, W24 opens
the listening port and awaits a connection. If LPRT is not defined, but
HSRV (Host Server) is defined, W24 immediately opens a SerialNET
socket link to the server.
AT+i @S NM D
-or-
AT+iSNMD=3
SOptional Deferred Connection mode. When this flag is specified, W24
automatically goes online (as in the case of AT+i!SNMD). However, if the
HSRV parameter is defined, a socket is not opened until data arrives on the
local serial port.
If the SerialNET mode listening port is defined (LPRT), W24 opens a
listening socket and waits for a remote connection during the idle period
before data arrives on the local serial port.
When the SerialNET socket type (STYP) is TCP and serial data arrives,
W24 buffers the data in the MBTB Buffer and tries to connect to HSR0. If
HSR0 does not respond, W24 tries HSR1, then HSR2. If all three
connection attempts fail, W24 retries them all. After three full retry cycles,
W24 dumps the MBTB buffer and remains idle until new serial data arrives.
AT+iSNMD=4 Optional SerialNET over TELNET mode. In this mode, W24 opens a data
socket as a TELNET socket, which allows negotiations of TELNET options
over the same socket while the host is sending and receiving raw data only.
This mode partially supports the RFC2217 standard.
Before issuing this command, you must set W24's Host Interface to
USART0 (HIF=1) or USART1 (HIF=2). For more information about this
mode, refer to the SerialNET over TELNET description.
Result Code:
I/OK If all minimum required parameters for SerialNET mode operation are
defined (HSRV or LPRT and, in a modem environment, also ISP1, USRN,
PWD).
I/ERROR Otherwise.
Followed by:
I/DONE After successfully activating SerialNET mode when using. Allow a 2.5
seconds delay for W24 re-initialization.
-or-