Design And Implementation Of AFDX Network Switch Software Based On HK664SW

In order to meet the technical requirements of high bandwidth and data security and reliable interaction in key tasks and information systems,the new generation of avionics system has formulated AFDX network protocol,which solves the bottlenecks of complex wiring,multiple connectors,low transmission rate and short transmission distance in the early point-to-point and bus transmission modes of electronic systems.It improves the performance of airborne bus network.In recent years,with the widespread application of AFDX network in transport,airliner and helicopter,the performance of AFDX switch,the core component,directly affects the whole network system.There are relatively few studies on switches in China.In addition to the urgent need for switches in airborne systems,it is urgent to accelerate the research and development of AFDX network switches to solve the problems of switching efficiency and accuracy of mode switching.This topic comes from the national ministries and commissions,and studies the related technology of AFDX network switch software design to meet the aviation application requirements of AFDX network switch products.This thesis analyses the operation mechanism of AFDX network,switch working mechanism and storage and forwarding principle,adopts structure-oriented and modular design method,and designs multi-threaded invocation mechanism.At the same time,by setting priority,the application and release of signal quantity,structure and storage resources can be rationally used to avoid mutual impact between software interfaces.Suddenly,through the analysis of application characteristics,the software and hardware interaction principle and implementation scheme of AFDX network switch software are planned,and the detailed design flow of initialization,operation mode management,serial port console,Ethernet data processing,BIT test,embedded ES protocol stack,ARINC615 A data loading and unloading and SNMP network management module are completed.At the same time,the relevant design function requirements,return state control,correct and error handling scheme are given.Aiming at the system architecture and specific functional modules of AFDX network switch software,the software verification scheme is designed,and three verification platforms are constructed: module verification,protocol conformance verification,system integration and joint test.By testing the independent module,the correctness of each functional interface is confirmed,and the configuration of switch,embedded system,forwarding(filtering and alarm),monitoring and capturing functions meet the design requirements.At the same time,in order to ensure that the switch products meet the requirements of the international AIM test platform and meet the application requirements of the system,the paper concludes.Systematic protocol conformance testing was carried out with AFDX network switch(10 categories of major items and 58 minor items were tested to satisfy 24 port non-blocking switching of the switch.Basic communication,filtering function,traffic alarm,exchange,monitoring,configuration,operation mode,data loading,pin programming and performance tests were passed.The switch operating system and software start-up time is 12.5s,which meets the design requirements of less than 20 s,determines the degree of adaptation between the software and the system,and meets the technical specifications of the switch in ARINC664 protocol.Finally,in order to meet the real scenario of the AFDX network in airborne applications and the application requirements of the AFDX network switch software,The system simulation test and joint test environment are designed to test the network function.The software verification of AFDX network switch reaches 100% coverage.It meets the application requirements of AFDX network switch and the requirements of ARINC664 protocol specification,and achieves the expected effect.