基于单片机的CAN实验系统设计外文翻译.doc

机 电 与 车 辆 学 院 毕 业 设 计（论 文） 外 文 翻 译 题 目：基于单片机的CAN实验系统设计 专 业： 电子信息工程 班 级： 姓 名： 学 号： 指导教师： 日 期： 2012年5月29日 How the CAN network functions Principles of data exchange. When data are transmitted by CAN, no stations are addressed, but instead, the content of the message (e.g. rpm or engine temperature) is designated by an identifier that is unique throughout the network. The identifier defines not only the content but also the priority of the message. This is important for bus allocation when several stations are competing for bus access. If the CPU of a given station wishes to send a message to one or more stations, it passes the data to be transmitted and their identifiers to the assigned CAN chip (”Makeready”). This is all the CPU has to do to initiate data exchange. The message is constructed and transmitted by the CAN chip. As soon as the CAN chip receives the bus allocation (”Send Message”) all other stations on the CAN network become receivers of this message (”Receive Message”). Each station in the CAN network, having received the message correctly, performs an acceptance test to determine whether the data received are relevant for that station (”Select”). If the data are of significance for the station concerned they are processed (”Accept”), otherwise they are ignored. A high degree of system and configuration flexibility is achieved as a result of the content-oriented addressing scheme. It is very easy to add stations to the existing CAN network without making any hardware or software modifications to the existing stations,provided that the new stations are purely receivers.Because the data transmission protocol does not require physical destination addresses for the individual components, it supports the concept of modular electronics and also permits multiple reception (broadcast, multicast) and the synchronization of distributed processes: measurements needed a