Research And Development Of Non-Central-Switching Bus Structure Train Inter-Communication System

Telephone communication is the most widely employed ways of communication in the world. Telephone communication is deeply embedded in people's lives as the national economic depends. Because of the speciality of railway transportation, telephone communication does not spread widely in the passenger trains in our country. At present inter communication is realized by interphone system in most of the passenger trains. Interphone communication has many disadvantages such as serious noise, bad quality of voice, lack of pertinence of calling.In this paper, on the basis of considering the train communication environment and dynamically grouping, the non-central-switching bus structure train inter-communication system is developed, which is used for inter communication in trains. There is a extension telephone in the crew-cabin of each coach, and the telephone's address corresponds to the number of the coach. In addition there is a broadcasting telephone whose address is set to 33 in broadcasting room, but the broadcasting room can be placed in any coach of the train. The bus topological structure and distributed control technology are adopted in the system, which doesn't set the central switching and in which the extension telephones are independence of each other and communicate with each other through a shared bus. The system can realize three call mode including single-call, group-call and interrupt-call, in addition each extension telephone can set its address by itself.First, the paper introduces the reason why it is designed and where it is suited to be applied. Then, how to establish the communication model and how to realize communication protocol are discussed, all system signalings are introduced. On the basis of the discussion, the main characteristics and working progress of the system are introduced. At the same time, the principle and realization of hardware and software are described in detail, and. Finally the design of multi-channel bus intercom system is proposed.Non-central-switching bus structure train inter-communication system has many advantages such as fast communication, low cost but high utilization factor of the channel, flexibility for increasing users, easy wiring installation, convenience for using and maintaining and so on. It can replace the same type of product abroad. At present, the system is employed in the top-grade passenger trains in our country. It improves the safety and reliability of railway transportation. It also increases the work efficient of trainmen and can provide fast and convenient services to passengers. The system makes railway transportation more competitive. Besides in trains, the system can replace the calling system used in hospitals, barracks , hotels and so on. It can also spread for production dispatch in enterprises.