CAN Bus Module for Arduino, Raspberry Pi and Intel Galileo [Xbee Socket]

CAN is a multi-master broadcast serial bus standard for connecting electronic control units (ECUs). Each node is able to send and receive messages, but not simultaneously. A message consists primarily of an ID (identifier), which represents the priority of the message. A CAN message that is transmitted with highest priority will succeed and the node transmitting the lower priority message will sense this and back off and wait.

The information is transmitted by two twisted wires that connect all system modules. It is transmitted by voltage difference between the two levels. The high voltage value represents 1 and low 0. Its combination forms an appropriate message.

Documentation:
CAN Bus Tutorial