The first option is to select the brand of your protocol box, the machine can be adapted to several brands of protocol boxes, you choose the brand of the protocol box according to your actual use of the protocol box, the protocol box on the back of the machine box has the brand of the protocol box, in accordance with the choice of the box, and then the back of the option to select the model of your car on the line.
If your model doesn't have CAN, then just ignore this option. Generally, the installer will adjust the agreement, individuals do not need to operate, re-option of the agreement need to be careful, some machines are adapted to the physical buttons, after selecting the agreement will result in the failure of the physical buttons, you must re-brush to solve the problem.
Precautions
Car navigation protocol box is connected to the navigation tail line on a square box, it is the data output, in order to realize the car computer and navigation information communication. It is more often used in high end cars to decode the original air conditioning display, steering wheel control, door opening information and other functions.
CAN's high performance and reliability have been recognized and are widely used in industrial automation, ships, medical equipment, industrial equipment, and so on. Fieldbus is one of the hotspots of technological development in the field of automation today, and is known as the computer LAN in the field of automation. Its appearance for distributed control systems to achieve real-time, reliable data communication between the nodes provides a strong technical support.
Reference: Baidu Encyclopedia-CAN bus