Matrix user forums

My question is why there is a need to use can & lin bus?

Where ?

I'm sorry I don't get it ^^"

i mean to ask whats the point in using lin or can bus, in car electronics? i mean why they are so useful?

Because it's an easy and fast way to connect electronic devices to each other, I suppose.

http://en.wikipedia.org/wiki/Controller_area_network
http://en.wikipedia.org/wiki/Local_Interconnect_Network

Hello,

1) Saves on a hugely complicated wiring loom as cars get more and more complicated. Pre CAN wiring looms were massive and very expensive to make and fit.

2) Very easy to debug problems such as shorts or breaks in the wiring loom.

3) Allows diagnostics and event tracking which would not be possible with a larger wiring loom.

4) Very good noise rejection allowing for reliable communications.

5) Open standards which means the manufacturers can design their own protocol and make their own debug tools.

6) Lin is generally used in less critical systems eg electric window control as it is cheaper to implement then CAN on a per node basis.

thanks for educating benj

HI.

Ben mentioned the most important things, but the open source is good and bad, if you don't have the manufacturer tool, there is nothing you can do, even if you know canbus very well (like NMEA 2000, it was closed by th id:s quite long time)...
The canbus is designed to be fast communication bus at the vehicle electronics, and there it has been adopted in industry and marine(like device net, profibus and NMEA 2000 the seems to be canbus physical layer in newest versions) ..
One thing is very good addressing, the address itself contains the message priority, and the bus physical layer set the highest priority message first, if the collision occurs...
And because canbus is based by message id:s the data is almost realtime, when data is ready, it can be sent at the bus right away, and it can be received by multiple devices, based on message id.
The modern car usually have two canbus, 125-250kb/s at the body electronics, and the 500kb/s at the safety electronics...

Mika

got it!!!!:) thanks guyz.