Design And Research Of The Network Switch Applied To Integrated Navigation System

Along with the vigorous development of computer technology and the continuous modernization of the equipment on ship, the integrated navigation system are required to provide not only accurate location information, but also more navigational information for the weapon system, control system and other systems. The traditional communication programs such as serial port and CAN network are increasingly unable to meet the large capacity and real-time requirements of the communications between all systems, Ethernet are widely used in integrated navigation system because of its real-time, high reliability, low prices, and other characteristics. The control system can obtain all kinds of marine environmental information from the integrated navigation system at any moment so that achieves the best control of the ship.Switches are core facilities of the wired Ethernet establishment, with our country's promoting independent innovation in science and technology, and the integrated navigation system requiring high reliability and network security of the switch, independent development and production Ethernet switch for integrated navigation system has become an urgent work.In this paper, Open Systems Interconnection Reference Model and Ethernet data frame structure was introduced firstly, then a detailed analysis of the working principle and performance parameters of Ethernet switches provide a theoretical basis for the systemic design. Subsequently based on our school's Integrated Navigation Console (INC), chooses the wide temperature-range, low power, non-integrated MAC (RTL8308B) and PHY (RTL8208B) chips, expatiated on the modular hardware design. The switch is divided into three modules: interface circuits, power circuits and exchange-functional unit, each module are detailedly designed and debugged based on the INC circumstances. In software respect, according to the IEEE802.3 standard, mainly research the RTL-level implement method of the data receiving and transmitting module based on Verilog HDL language. Finally compiles two testing procedures for the evaluation of the switch's transmission rate and packet-loss rate, and compare with similar switches on the market.Through the long running and comparison tests, the performance of this design was proved that it had reached the application requirement of INC, and the design provides a network communication programs with merits of real-time, high reliability, low power consumption and low cost for INC. The research project has a superior value in engineering application.