1. Controller Area Network CAN-BUS
1, CAN-BUS origin
Controller Area Network (ControllerAreaNetwork abbreviated CAN) originally in the German company Bosch 1983 for automotive applications developed an effective tool to support distributed control and real-time control of the serial communication network, it belongs to the category field bus (fieldBus) of. In November 1993, ISO formally promulgated the Controller Area Network CAN International Standard (ISO11898), as controller area network standardization to promote paved the way. Now it has become one of the international open field bus most widely used.
2, CAN-BUS Principle
CAN (Controller Area Network) that is a controller area network. Application site, multi-node bidirectional serial digital communication between the computer systems of the measuring device, is an open, digital, multi-point communication control underlying network. CAN protocol based on ISO / OSI model, which model structure with three layers. Agreement is divided into Can2.0A, CAN2.0B, CANopen several.
CAN-BUS i.e., CAN bus, called ldquo; Controller Area Network bus (ControllerAreaNetwork-BUS) rdquo ;. CAN bus communication medium may twisted pair, coaxial cable and optical fiber. Communication distance and wave hold rate, and the maximum communication distance up to 10km, the largest communications holding waves up to 1Mdps. CAN bus arbitration identification using 11-bit bus architecture and non-destructive arbitration mechanism, may determine the priority of the data block, to ensure that the highest priority node need not wait for a conflict when conflict network node. CAN bus using the multi-master contention bus structure having a pluralityFeatures of the broadcast communication and a serial bus master operation and decentralized arbitration. Any node on the CAN bus can be sent at any time other nodes on its own initiative without any differentiation of the network information, it is possible to achieve free communication between nodes. CAN bus protocol has been accredited by the International Organization for Standardization, technology is relatively mature, controlled? Film has been commercialized, cost-effective, especially for data communication between distributed measurement and control systems.
3, CAN-BUS development
Can-Bus bus technology was first used on communications liaison aircraft, tanks and other weapons of electronic systems. This technology will be used for civilian car originated in Europe, in the car this car bus networks for a variety of sensor data transfer.
With the continuous improvement and development of CAN-BUS, as a technologically advanced, high reliability, perfect function, reasonable cost of remote network communication control, CAN-BUS is no longer confined to the field of automotive electronics , it has also been widely applied to other various automation control system. In Europe, the Americas, Asia bus CAN-bus technology is already widely used in the field of construction machinery, some famous international construction machinery companies such as CAT, VOLVO, Liebherr and so widely used CAN-bus bus on their products technology, greatly improving the reliability of the machine can be detected and maintainability, while improving the level of intelligence. In the country, CAN-bus bus control system began in the car’s control systems widely used in construction machinery industry (such as automatic control, intelligent buildings, power systems, security monitoring and other fields) are also being gradually popularized.
. 4, CAN-BUS applications
CAN-BUS bus currently used in the car more and more popular, not limited to high-end vehicles (such as Polo , Jetta, Passat), mid-range cars (such as Shanghai Volkswagen Touran) are increasingly equipped with CAN-bUS bus.
CAN-BUS bus automobiles generally three types: a high-speed driving system (rate up to 500kb / s or more) connection objects include an engine ECU, ABSECU, SRSECU, combination meter and the like; low-speed CAN bus comfort system for the vehicle body (1 rate00kb / s), with a connection object set locks, electric windows, mirrors, lighting and other car; may also have additional intelligent communication systems for satellite navigation.
around the sensor body, with a variety of car data is sent to the ldquo; bus rdquo;, these data does not specify the only recipient, who needs to receive the end of the data are available from ldquo ; bus rdquo; read the necessary information. Can bus data transfer is very fast, can achieve effective data transmission 32bytes per second, which can effectively guarantee the effectiveness and accuracy of the data. Conventional car body in the nacelle and requires a large number of embedded wire harness to pass signals collected by the sensor, and the application Can-Bus bus technology can significantly reduce the number of car body wire harness, a combination of engine, gearbox, airbags, instrument cluster, ABS computer diagnostic systems and comfort. Via a controller area network, so that each system of the vehicle coordinate the operation, information sharing, to ensure that vehicles traveling more safe, comfortable and reliable.