origin
In the 1980s, Robert Bosch introduced a new type of serial bus, the CAN Controller Area Network, at the SAE (Automotive Engineering Association) conference, which was the moment when CAN was born. Today, almost every new passenger car in Europe is equipped with a CAN LAN. Similarly, CAN is also used in other types of vehicles, from trains to ships or for industrial control. CAN has become one of the most important buses in the world – even leading the serial bus.
How the CAN bus works
The CAN bus uses serial data transmission, which can run on a 40m twisted pair at a rate of 1Mb/s, or it can be connected using fiber optic cable, and the bus protocol supports multi-master controllers on this bus. CAN and I2C bus are very similar in many details, but there are some obvious differences.
When a node (station) on the CAN bus transmits data, it broadcasts it to all nodes in the network in the form of messages. For each node, whether the data is sent to itself or not, it is received. The 11-character character at the beginning of each group of messages is an identifier that defines the priority of the message. This message format is called a content-oriented addressing scheme. In the same system the identifier is unique and it is not possible for two stations to send messages with the same identifier. This configuration is important when several stations compete for bus reads at the same time.
When a station wants to send data to other stations, the CPU of the station sends the data to be sent and its own identifier to the CAN chip of the station, and is in the ready state; when it receives the bus assignment, it changes to send the message. status. The CAN chip sends the data according to the protocol and is organized into a certain message format. At this time, other stations on the network are in the receiving state. Each station in the receiving state detects the received message and determines whether the message is sent to itself to determine whether to receive it.
Since the CAN bus is a content-oriented addressing scheme, it is easy to build a high-level control system and configure it flexibly. We can easily add some new stations to the CAN bus without having to modify them in hardware or software. When the new station provided is a pure data receiving device, the data transfer protocol does not require a separate portion to have a physical destination address. It allows the distribution process to be synchronized, ie when the controller on the bus needs to measure data, it can be obtained online, without having to have its own separate sensor for each controller.
CAN bus features
1. It has the advantages of strong real-time performance, long transmission distance, strong anti-electromagnetic interference capability and low cost;
2. It adopts two-wire serial communication mode, which has strong error detection capability and can work in high noise interference environment;
3. With priority and arbitration function, multiple control modules are connected to CAN-bus through CAN controller to form a multi-host local network;
4. The message can be received or blocked according to the ID of the message;
5. Reliable error handling and error detection mechanism;
6. After the sent information is destroyed, it can be automatically resent;
7. The node has the function of automatically exiting the bus in case of serious error;
8. The message does not contain the source address or the destination address, and only the identifier is used to indicate the function information and the priority information.
CAN bus application
The advantages of the CAN bus in networking and communication functions and its high cost performance have determined that it has broad application prospects and development potential in many fields. Some of these applications have in common: CAN is actually the role of a computer LAN that acts as a bus topology in the field. No matter what the occasion, it bears the real-time communication between any node, but it has the advantages of simple structure, high speed, anti-interference, reliability and low price. The CAN bus was originally designed for automotive electronic control systems. The use of CAN in cars currently produced in Europe is very common. Not only that, but the technology has been extended to trains, ships and other vehicles.
(1) Application of CAN bus technology : Most famous foreign cars have adopted CAN bus technology, such as Volvo, Lincoln, Audi, BMW, etc., while domestic automobile brands, such as Chery, have already applied bus technology to several models. . CAN bus technology is to send various driving data of the car to the "bus" through sensors all over the body. On this information sharing platform, all the receiving ends that need these data can read the required information from the "bus". Therefore, the various systems of the car can coordinate operation, share information, ensure safe driving, comfortable and reliable. In general, the more high-end cars are equipped with more CAN_BUS, the higher the price, such as Touran, Passat and other models are equipped with multiple CAN bus.
(2) Hardware design of automotive CAN bus node ECU : The core technology of automotive CAN bus research and development is to design the ECU with CAN interface. The CAN bus module of ECU is composed of CAN controller and CAN transceiver. The CAN controller performs a complete CAN protocol and completes communication functions, including information buffering and receive filtering. The CAN transceiver is required as an interface between the CAN controller and the physical bus, which implements the conversion of the logic level signal between the CAN controller and the bus.
(3) Application of CAN bus in domestic independent brand cars : Due to the limitations of cost control and technical strength, CAN_BUS bus technology generally appears in foreign high-end cars. In the A-class and below models, most of this technology Appeared in joint venture brands, such as POLO, New Bora and so on. Among the self-owned brands, there are few models using CAN bus technology, and Fengyun 2 is the representative model. Fengyun 2 CAN bus technology can realize the communication of engine, gearbox, ABS, body, instrument and other controllers, so that the whole vehicle information can be shared in time. In Fengyun 2's combination instrument panel, more than 20 pieces of information such as stage mileage, accurate door display, and seat belt reminder are all displayed, which is doubled compared with the same level products, which increases the safety during driving.
(4) Future development trend of smart sensors : CAN bus has been applied to many advanced vehicles as a reliable automotive computer network bus. The CAN bus is applied to smart sensors, so that the signals obtained by the sensors can be real-time and reliable through the bus. Ground, high-speed and accurate transmission, enabling each car computer control unit to share all information and resources through the CAN bus, simplify wiring, reduce the number of sensors, avoid duplication of control functions, improve system reliability, reduce costs, and better match And coordinate the purpose of each control system. At the same time, since the entire intelligent sensor network adopts all-digital communication, the bus also has good anti-interference ability, and is the development trend of intelligent sensors and intelligent control networks in the future.
In addition, with the help of CAN bus technology, after the internal sensors realize information sharing, the number of interfaces of the wiring harness and the controller in the vehicle body is greatly reduced, and the mutual interference and wear of the excessive wiring harness are avoided, and the automobile electrical power is reduced. The failure rate of the system. Open the bonnet and see a clear and concise interior layout. In terms of maintenance, the application of CAN bus technology also makes the most convenient guarantee for troubleshooting. The CAN bus intelligent butler system complies with European and American OBDII standards and regulations, and realizes the function of online diagnosis. After the vehicle fails, each controller stores the fault code through the CAN bus intelligent housekeeping system. The professional diagnoses the fault status for the vehicle through the diagnostic instrument, quickly and accurately finds the fault point, and eliminates the fault in the first time. The use of CAN bus technology to achieve system integration of information transmission, greatly improve the response speed of various components, reduce the incidence of accessory wear, and correspondingly reduce maintenance costs; Moreover, the application of advanced integration technology has also greatly improved the vehicle itself The scientific and technological content enhances the competitiveness of products.
CAN bus data communication has outstanding reliability, real-time and flexibility. Due to its good performance and unique design, the CAN bus has received more and more attention, and it is the most widely used in the automotive field. Most famous automobile manufacturers in the world use the CAN bus to realize data communication between the internal control system of the vehicle and each detection and execution mechanism. At the same time, due to the characteristics of the CAN bus itself, its application range is no longer limited to the automotive industry, but to the automatic control, aerospace, marine, process industry, machinery industry, textile machinery, agricultural machinery, robots, CNC machine tools, medical equipment. And the development of sensors and other fields. CAN has become an international standard and has been recognized as one of several of the most promising fieldbuses.
| About Paper Covered Flat Copper Wire |
Wrapping materials: Power Cable Paper, High Density Insulation Paper, heat-resistant insulating paper, clupak paper, Nomex 410, all kinds of self-adhesive paper and other special insulation materials
As per Conductor Material:Copper , aluminum
As per Inner Conductor: Paper wrapped bare
Insulation thickness:Double paper covered (DPC) orTriple Paper Covered (TPC) ,According to Customer`s requirements
Conductor of Paper wrapped wire
Bare Wire Round Wire:Φ1.00mm-Φ5.00mm
Rectangular Wire thickness a:1.00mm-5.60mm
Width b:2.00mm-16.00mm
Conductor of Composite wires
Max wrapping layers once: 24 layers for Paper Covered Wire
4 layers per wire and 16 layers outside for composite wires
We could offer products of special requirements on conductor size, insulation layer thickness, or wire number of the composite.
Paper Covered Flat Copper Wire
Aluminum Enameled Wires,Paper Covered Flat Copper Wire,Cable Paper Covered Insulated,Paper Covered Insulated Wire
HENAN HUAYANG ELECTRICAL TECHNOLOGY GROUP CO.,LTD , https://www.huaonwire.com