The Smart Sam2S Tcp/Ip Operation; Communication Sockets - Intercel SMART SAM2S User Manual

Smart SAM2S User Guide V1.4

8 The Smart SAM2S TCP/IP Operation

The Smart SAM2S has a MCU (Microcontroller) to control the 2G module PHS8-P, the Smart SAM2S can be
operating in there different modes, defined by parameter SAMMODE:
-SAMMODE=0, modem is in dumb mode, when power on the MCU turn on the 2G module, check its baud
rate, turn on LED and release control of the 2G module to the connecting device, AT commands can be send
from serial port here after, the MCU keep monitor the 2G module Rx pin for AT$ commands and check time
in the POLLPERIOD parameter (to reset itself and the 2G module.
-SAMMODE=1, modem is in GPRS or PSD (Packet Switch Data) smart mode, the MCU is in total control of
the 2G module, on power up the software reads all parameters from flash and activates a GPSR connection,
it then creates an UDP and a TCP socket to listen for data transfer connection, opens an UDP and a TCP
socket to listen for remote AT commands connection, if programmed as TCP client it will tries to connect to
a remote TCP server, the modem then stays in GPRS online idle state waiting for CSD call, SMS, UDP data
or TCP connection, the software maintains GPRS connectivity by the mean of IP TRACE using
POLLPERIOD parameter stored in flash.
-SAMMODE=2, modem is in CSD (Circuit Switch Data) smart mode, this mode is used if SIM card is not
setup for GPRS, MCU is in total control of the 2G module, modem is always in waiting for CSD call or SMS.
The modem supports DDNS, for SIM card that has dynamic public IP address the software can performs
dynamic DNS updating to a DNS server (supporting dyndns.com and noip.com).
The modem provides security for remote management by keeping a list of SMS sending mobile numbers, a
list of CSD calling numbers, a list of PSD sending IP addresses and username and password login,
password data is encrypted for remote transaction.

8.1 Communication Sockets

TCP Data: Socket connection allows transparent data to pass through from host computer to the modem
serial port and vice versa, this operation is similar to the CSD data communication, in TCP
server mode the socket will be disconnected after 5 minutes of no data transfer.
UDP Data: Socket connection allows transparent data to pass through from host computer to the modem
serial port and vice versa, this operation is similar to the CSD data communication, a block
of data received from a remote UDP server will open a 2 minutes window for data to be
transfer from the serial port.
TCP AT Command:
the modem and receive its responses, socket will be disconnected after 5 minutes of no
activity, and socket also can be used for remote firmware update.
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Socket connection allows a user from the host computer to send AT commands to
Ver1.4