Research On Distributed-embedded Detecting System Based On Tcp/ip Transmission Technology

Embeded ethernet based on TCP/IP protocol has the advantages of high speed, long transmission distance, easy building, it can manage multi-nodes and easy to add and delete them. Distributed-embeded detecting system adopted embedded Ethernet as networking and transmission mode can meet the requirements of modern industrial detecting that the detecting process should be real-time and of high reliability, also it can fit the status that detected nodes becomes widespread and lager number.The paper presents a method for embedded system to connect to ehernet based on simplified TCP/IP protocol, it directly implement TCP/IP protocol on embedded system with software which uses fewer resources and cost less. What is more, the protocol statck is reconfigurable and revisable, also it can keep up with the develop- ment of network techonology by the way of software updating.In this subject, an embeded system using DSP TMS320C5509A and network controller DM9000A as kernel hardware has been designed, and build a distributed embeded bar code decoding and length measurement system based on TCP/IP protocol by synthesizing the application of linear array CCD and PBX in LAN.The paper mainly includes the following:1) Program a simplified TCP/IP statck which could be commonly used. In comparing the method of Ethernet access based on DSP system, the DSP chip,100Mbps NIC and program a simplified TCP / IP protocol stack is selected finnaly to meet the need that put embedded system through Ethernet. Then program the modularized protocol statck which can meet the basic demand of DSP system. The protocol stack includes APR, PING, IP, UDP and TCP. The stack can be used in many embedded processor and controller, it is of wide applicability.2) Raise the speed of transmission by using the NIC's resources and optimize the process of transimiting. Utilize the NIC as much as possible, choose the best function after comparing all the features of the NIC, such as, to calculate the head-checksum by hardware method instead of programming by software, choose dual-frame mode and so on; analyze the method to increase transmitting speed, for enlarge the length of the packet, open or close interrupt well-timed, the validity of these methods are confirmed by experiments. 3) The structure of the Embeded-detecting system and the software of Embeded system and Pc are both designed..Including the optical system, capturing unit, DSP control unit and data-process unit, Bar code recognition and length measurement are both completed. Embeded software based on TMS320C5509A is finished, algorithm for decoding bar and measuring length is designed; also software on Pc is finished.4) Relevant tests and experimens are token. Through communication tests, the available of the protocol statck is confirmed; the system are confirmed to meet the demand of the parameters through bar decoding and length measurement experiments; distributed system is also set up to illustrates the validity of the distributed-embeded detecting system.