Development of a controller area network (CAN) began in the 1980s and was published by the International Organization for Standardization (ISO). The CAN is applied under harsh conditions of electrical transmitting for providing a stable transmission. Therefore, a CAN is usually applied on, for example, a control system of vehicles, aerospace, maritime, industrial automation and medical equipment.
A transceiver is a device comprising both a transmitter and a receiver that are combined and share common circuitry or a single housing. Additionally, the transceiver can be a controller area network (CAN) transceiver. The CAN transceiver is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. The CAN transceiver is a message-based protocol, designed originally for multiplex electrical wiring within automobiles, but is also used in many other contexts. Additionally, the automobiles may also be understood to be a car, sport utility vehicle or suburban utility vehicle (SUV), or any known automobile in the art. Specifically in automobiles, automobile may have as many as 70 electronic control units (ECU) for various subsystems, such as the engine control unit, transmission, airbags, antilock braking/ABS, cruise control, electric power steering, audio systems, power windows, doors, mirror adjustment, battery and recharging systems for hybrid/electric cars, etc. Some of these form independent subsystems, but communications among each other are essential. As such, a subsystem may need to control actuators or receive feedback from sensors, and thus, the CAN transceiver was devised to fill this need. The CAN transceiver allows interconnections between different vehicle systems for a wide range of safety, economy and convenience features to be implemented. If The CAN transceiver is not used and such features were “hard-wired” using traditional automotive electrics, the “hard-wired” functionality would add cost and complexity.
As discussed above, the CAN transceiver may be used in various systems of automobiles. For example, when the automobiles have an auto start/stop feature, various sensor inputs from around the automobile (speed sensors, steering angle, air conditioning on/off, engine temperature) are collated via the CAN transceiver to determine whether the engine can be shut down when stationary for improved fuel economy and emissions. In another instance, the CAN transceivers are used with the electric park brakes. As such, the “hold” functionality of the electric park brakes takes input from the car's tilt sensor (may also be used by the burglar alarm) and the road speed sensors (may also be used by the ABS, engine control and traction control) via the CAN transceivers to determine if the car is stopped on an incline. Similarly, inputs from seat belt sensors (part of the airbag controls) are fed from the CAN transceivers to determine if the seat belts are fastened, so that the parking brake may automatically release upon moving off. Additionally, when the driver engages reverse gear, the transmission control unit can send a signal via the CAN transceivers in the parking assist systems to activate both the parking sensor systems.