Transcript Document

Interconnection
Protocol
Mustafa Kara
514051008
Term Work
Specification
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RS232 interfaces at a computer will be
connected to a ethernet network.
All the communication ports could be shared.
We can only acces to these ports using only
ethernet network because driver software will
lock RS232 ports this.
RS232 Driver
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This software will detect all the RS232 ports and
then locks them so that no other SW use them. The
purpose of locking mechanism let local users to
access these serial ports using this IP based drivers.
A client SW can configure these ports for example
give a description for this port etc.
Driver SW then share these ports using a
communication protocol so that each packet send to
the computer will be oriented to the proper ports.
Communication Protocol
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I implemented my
communication protocol using
TCP/IP payload.
I’ve just implemented ethernet
based communication protocol
and a simple communication
protocol between a Pseudo
Serial Device and Host
computer.
There is a plenty of
communication protocol
between a computer and Serial
Device for example T.30 fax
communication protocol.
Protocol Description
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First a computer ask for
available serial devices on
the computer.
Computer send back the list
of all available serial ports.
Client sends data to the
concerning serial port
conforme to communication
protocol between serial
device and computer which
contains this port.
Mesage Structure
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Client to Server Mesages Structure
HEADER (4 Byte) OPCODE ( 4 Byte)
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PAYLOAD
Server to Client Message Structure
HEADER (4 Byte)
RESSOURCE STATE ( 4 Byte)
PAYLOAD
Protocol Layers
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I’ve implemented my
protocol at “Application
Layer” by doing so I
dont deal with network
traffic management
complexity.
To guarantee I prefered
to use TCP protocol at
my application.
Virtual RS232 Ports
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For offline testing I’ve
used Virtual Serial
Ports program which
allows to creat any
number of serial port
pair which are
connected each
other via null modem
cable means these
ports have separated
physical layers.
Aim of the project
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I planned to use this program to connect to a
RS232 based embedded SW verification
module to test TV/STB/IDTV software
modules using black box test strategies.
One of the most important phase in
embedded sw development is the verification
phase. It’s important to have a simple and
effective test framework in order to have
consistent sw.
Application Exemple-1
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By using my project I
can share any kind of
RS232 based devices
over ethernet network.
For example I can
share an old
fax/modem device by
adding to the driver
software a standard
communication protocol
for faxes T.30.
Application Exemple-2
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I’ve a module which is
connected to a ethernet
network and permit to
me to share RS232
I can also use this
software to program a
flash memory using a
SPI interfaced board.
For example a TV
chassis.
Application Exemple-3
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We can get data from
sensors in an private
local network maybe in
an factory environment.
We can also make
communicate some
serially connected
sensors to an ethernet
network.
Potential Problems
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There is many kind of serial connection
based devices and each of them has a
dedicated communication protocol between
devices and host computer so, in order to this
program might be useful we must also know
which standards are used for communication.
While writing such sharing software I’ve to
also deal with complex shared ressource
management.
Tools Used
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I prefered to use Java SDK to develop
software because it’s higher level language
so it’s easy to program with it. In addition
there exist a test framework named JUNIT
which allow to create easily test cases for any
Java classes.
I’ve also used Sun Communication API to
access Serial Ports.
I’ve used also JCreator IDE for SW
development.