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Controller area network - Can

Introduction

Controller area networks are also known as Can or Can bus as short typical standard that has been designed for microcontroller in order to insatiate communications without central host. It’s a bus vehicle by which microcontrollers can easily communicate with each other devices .its, messenger technology is truly based on message protocols which are best suited for the automotive devices but latest improvements and enhancements have diversified its usage. No they are also used in the industrial, medical and commercial sectors for different purposes

Historical Background
Controller Area Network bus was originally introduced in 1983 and was officially released in 1986 at the SAE (Society of Automotive Engineering) in ten Michigan. The very first Can chip was manufactured by the Intel and Philips which appeared in the market in 1987 officially, there are many revised versions of controller area networks area available in the market such as CAN 2.0.Can is one of the five famous protocols that are frequently in the OBD for the diagnosing the standard of vehicles.

How controller Area Network works.
CAN are based on the multi master broadcasting technology. It uses a serial bus for the transmission and for connecting electronic control units. Its starts its working by sending and receiving the messages but this is done on the individual mode not simultaneously. Each message that is sent comprises of the ID which represents the priority message up to eight bytes of the data. This complete message is broadcasted through the serial bus and the concerned id matching device receives the message and responds back through the same serial bus. NRZ technology (Non return to Zero) is used to sense the nodes. The device that are mostly connected to the CAN are the sensors, Actuator and other controlling device through the connectors of the signal strait bus. Host processor is between the Can controller and devices.
The transmission tarts when the bus is free to carry the message otherwise communication is not possible .In the cases where to devices generate the message simultaneously send it to the bus then one of the message dominates the id and initialized first and second waits in the queue for its turn to get transmitted. This process is known as the id arbitration.

Node components
Every node needs some of the component such as.

Host processor host processor is responsible for controlling the received messages.

CAN controller. CAN controller controls the synchronizations of the clock for sending receiving and id domination of the multiple messages.

Transceiver transceiver is another component that is responsible for controlling the level of signals form the bus. It adapts and sends the signal forward to the other devices.

Applications of the Controller Area Networks
Can controller are used in many applications such as automotives and also for industrial purposes. Typical controller area circuits are used in the advance engines control systems for integrating the activities of the car engine. it integrates and synchronized that audio system, windows,doors, mirror adjustments ,wipers, airbags, antilock systems, Door locks and other functions of the car .in the field of technology it s used for the Media Access control and physical layer management in OSI model. What type of protocol must be controlled by the Can this totally depends on the choice of the designer. They are well known for their data transmission technology that is why they are used in different networks for connecting the components with the proper integration with the logic gates.

Future Perception
Controller area network are still limited because they don’t support two way message transmissions. In the near future it can be enhanced and could prove itself as a successful network controller.