Interconnection Protocol Mustafa Kara Term Work

Specification 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 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 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 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 Client to Server Mesages Structure HEADER (4 Byte)OPCODE ( 4 Byte)PAYLOAD HEADER (4 Byte)RESSOURCE STATE ( 4 Byte)PAYLOAD Server to Client Message Structure

Protocol Layers 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 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 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 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 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 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 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 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.