The characteristics of the three major buses CAN, LIN, Flexray

As new energy vehicles are listed in the seven strategic emerging industries that the country accelerates cultivation and development, the intelligentization, digital networking and energy-saving of automobiles have become the general direction of automobile development. The car bus is the basis for digital network. This article will talk to you about the three major buses of today's cars, CAN, LIN, and Flexray.
Today, society has entered the era of information networks. People hope that cars are not just a means of transportation. They also hope that cars are an extension of life and work. In cars, they can stay in their own offices and homes. Telephone, Internet, entertainment, work.
The increase in functions has also led to a dramatic increase in the number of electronic devices on the car, and various car buses have emerged. The car bus we are most familiar with is CAN, which may be strange to LIN and Flexray. Then, let's introduce the three kinds of car buses for everyone.

　 First, the birth of the car bus The birth of the car bus is inseparable from the development of automotive electronics. The degree of automotive electronics is also seen as an important indicator of the level of modern cars. Most of the traditional automotive electronics use a single point-to-point communication method, which has little connection with each other, which will inevitably form a huge wiring system. According to statistics, in a high-end car using traditional wiring methods, the length of the wire can reach 2000 meters, the number of electrical nodes can reach 1500, and the number will be doubled every 10 years.

　 This further exacerbates the contradiction between the thick wire harness and the limited available space on the car. Regardless of material cost or work efficiency, traditional wiring methods cannot adapt to the development of modern automobiles. In addition, in order to meet the real-time requirements of each electronic system, public data (such as engine speed, wheel speed, throttle pedal position, etc.) must be shared, and the requirements for real-time performance of each control unit are different. Therefore, the traditional electrical network has been unable to adapt to the development of modern automotive electronic systems, so the new automotive bus technology came into being.

　 Second, CAN bus CAN bus, also known as car bus, is called "Controller Area Network", is a serial communication network that can effectively support distributed control and real-time control. It connects the individual control units in some form (mostly star) to form a complete system.
The CAN bus was originally developed as a serial communication protocol by Bosch in Germany to solve the data exchange between many electronic control modules (ECUs) in modern automobiles. Nowadays it has been widely used in automotive electronic systems, becoming the main industry standard of the European automotive industry, representing the mainstream development trend of automotive electronic control networks.

　 Many famous automobile manufacturers in the world, such as Volkswagen, Benz, BMW, Porsche, Rolls.Royce, etc., have adopted CAN bus to realize the interior of the car. Control system data communication.
Third, LIN bus LIN is a new type of low-cost open serial communication protocol jointly launched by Motorola and Audi (Audio). It is mainly used in distributed electronic control systems in vehicles, especially for intelligent Digital communication of sensors or actuators. Mainly used in electric door and window, seat adjustment, lighting and other controls.
A typical LIN network can have up to 12 nodes. Taking the door and window control as an example, there are door locks, window glass switches, window lift motors, operation buttons, etc. on the door, and only one LIN network can be connected. Through the CAN gateway, the LIN network can also exchange information with other systems of the car to achieve richer functions. LIN has become an international standard and is accepted by most car manufacturers and component manufacturers.

　 Flexray bus Flexray is a high-speed, deterministic, fault-tolerant bus technology for automobiles. It combines event triggering and time-triggering to provide efficient network utilization and system flexibility. Sexual characteristics can be used as the backbone of the new generation of automotive internal networks.
Flexray can be used in passive bus and star network topologies, or in a combined topology of the two. Both topologies support dual-channel ECUs that integrate multiple system-level functions to save production costs and reduce complexity. The dual-channel architecture provides redundancy and doubles the available bandwidth. The maximum data transfer rate per channel is 10Mbps. At present, Flexray is mainly used in safety-critical wire control systems and power systems, and is used in BMW's high-end cars.

　 V. Summary As a reliable car bus , CAN has been widely used in high-end cars. As a supplement to CAN, LIN has become an international standard. Flexray, which is more advanced than CAN, is growing rapidly. The development of the car bus has become overwhelming. The ZDS2024plus oscilloscope comes standard with CAN, LIN, Flexray protocol decoding, and supports the latest CAN FD decoding. We are willing to contribute to the development of the automotive bus.