Research On Communication Technology Of Remote Fault Diagnosis System

The Remote Fault Diagnosis System is based on the traditional monitoring, diagnosis and maintenance technology, which is the combination of network, database, artificial intelligence and other related technology. The Remote Fault Diagnosis System use networks to realize remote monitoring and diagnosis.At first, paper analyse the application of remote fault diagnosis system, which is composed by expert-level diagnosis layer, diagnostic testing center layer, scene testing equipment layer and testing objects layer. Analysis the problems during data communications between two bottom layers.Existing TCP protocol data transmission is not an effective solution to the problem of insufficient bandwidth, also unable to effectively protect the security of data transmission.After detailed analysis of data in system and treatment process, deeply mining the logic relationships between data compression and data security transmission process, propose a unified model called data compression and security transmission model, which is based on the processing modules. Based on the existing TCP protocol,add data compression \ decompression, data encryption \ decryption, data authentication and data preprocessing function modules to application layer to rebuild a new protocol, which is a effective solution to deal with the data transmission problems between the scene layer test equipment and diagnostic testing center layer.In view of the safety of test data transmission through the network, especially the application of military equipment test, based on the detailed comparison of numerous data encryption technologies, papers design a multiple certifications, mixed encrpytion system, which is consisted of single-key cryptosystem, public key cryptography and authentication algorithm, can effectively guarantee the safety and integrity during the test data transmission.Through the research of existing data compression algorithms, to solute the problems such as the limited length dictionary table, long time to find out the results, add the dynamic extension of the length of the table, adjust the table by compression radio and the hash function to improve LZW data compression algorithm. With the thinking of compression between frames of MPEG4, design the "cyclical margin compression algorithm", with the developed LZW, design a cascade of data...