Used for automobile fault detection, CAN wire is twisted pair, twisted together to prevent external interference. CAN line is used for communication between computers with different functions in automobiles. If a car reports a fault related to CAN communication, it can be directly detected.
Detection method of automobile can l5mine: terminal resistance measurement: disconnect the connection of vehicle battery, wait for 5 minutes, and then measure until all capacitors in the system are discharged; Voltage measurement: Measure the grounding voltage of CAN-L or CAN-H. ..
Waveform measurement: Connect the red measuring terminal of the first channel of the instrument to the CAN-High line, the red measuring terminal of the second channel to the CAN-Low line, and the two black measuring terminals are grounded at the same time to read the measured data block.
Basic concepts:
CAN is the abbreviation of Controller Area Network (CAN) and is an ISO international standardized serial communication protocol. In the automobile industry, various electronic control systems have been developed for the requirements of safety, comfort, convenience, low pollution and low cost. Because the data types used in communication between these systems and the requirements for reliability are different.
Many cases are composed of multiple buses, and the number of wire harnesses has also increased. In order to meet the needs of "reducing the number of wire harnesses" and "high-speed communication of a large amount of data through multiple LANs", the German Electric Company 1986 Bosch developed the CAN communication protocol for automobiles. Since then, CAN has been standardized by ISO/KOOC-0//KOOC-0/898 and ISO/KOOC-0//KOOC-0/5/KOOC-0/9.
In Europe, it has become the standard protocol of automobile network. The high performance and high reliability of CAN have been recognized and widely used in industrial automation, ships, medical equipment, industrial equipment and other fields.
Fieldbus is one of the hot spots in the field of automation technology development, and it is called computer local area network in the field of automation. Its appearance provides strong technical support for distributed control system to realize real-time and reliable data communication between nodes.
Refer to the above? Baidu encyclopedia -CAN bus