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CAN Bus Communication

canbusCAN communication (Controller Area Network) is a type of communication that connects several modules on the same 2 wires network compared to point-to-point (peer to peer), which has a dedicated line for each direction. The use of two wires instead of one for the network is not a coincidence; this provides excellent immunity to noise (interference). Indeed, this feature allows the use of a differential communication which completely eliminates the induced noise on the network. The operation of a differential communication is rather simple; the data on the two wires are inverted with respect to each other and are subtracted from each other when receiving. If noise is induced, it will be positive on the two wires and it will be eliminated in the subtraction, while the relevant data will be retained because they are reversed: a positive minus a negative gives two positive!

Another advantage of this type of communication is its versatility in terms of communication speed (10kbps to 1Mbps) and the number of players possible on the network (in standard mode and 2048 more than 500 million in extended mode). These two major features are indispensable in the automotive industry. We use this type of communication to take various information about the vehicle and to communicate with it or for the communication between the different modules in the vehicle.

Martin Lessard, eng.
Director of R&D department