User's Manual

Table Of Contents
SerialNET Theory of Operation
AT+i Programmer‘s Manual Version 8.32 29-4
atomic, maintaining their original size. When a TCP connection is used, packets can be
combined before being actually transmitted. This follows from the stream nature of the
TCP protocol. Data originating in the remote system is routed to the local device as it is
made available. Flow control can be governed locally using hardware flow control only.
The PTD parameter can be used to define the number of packets to be cyclically
discarded in a SerialNET mode session. When PTD>0, iChip first discards <ptd> packets
before actually sending one to the SerialNET socket. This can be used to dilute repetitive
information.
29.7 Completing a SerialNET Session
A SerialNET session is completed when one of the following occurs:
The local device transmitted the disconnection string, as defined in the
DSTR
parameter.
Following an inactivity timeout, as defined in the
IATO parameter.
In a modem environment the iChip goes offline when the SerialNET session is
terminated.
In a LAN environment, the iChip reopens the SerialNET listening socket defined in the
LPRT parameter (if it is non-zero) to service future remote client connections.
29.8 SerialNET Failed Connection
If the iChip fails to establish a SerialNET connection, SerialNET mode is deactivated for
a delay period defined in the SNRD parameter.
29.9 Local Serial Port Configuration
Prior to entering SerialNET mode, iChip‘s local serial port can be configured to comply
with a wide range of devices by assigning a value to the
SNSI parameter.
Serial port configuration entails settings to:
Baud rate:
300, 1200, 2400, 4800, 9600, 19200, 38400, 56K or 115K
Bits/byte:
7 or 8
Parity:
None, Even, or Odd
Stop Bit:
Must be 1
Flow Control:
None (0) or Hardware (1)
29.10 Activation Command
The iChip is forced into SerialNET mode by issuing the following command:
AT+i[!|@]SNMD
If the minimal SerialNET parameters are defined, iChip replies with I/OK followed by
I/DONE or I/ONLINE or I/OFFLINE.