On a single CAN bus, any node can transmit data.
Nodes arbitrate for use of the bus, so that, in the event of two or more nodes
attempting transmission, messages are transmitted one after another according to their priority.
Nondestructive and transparent arbitration is possible because
transmission of a dominant bit overwrites the recessive busstate.
The CAN controller of each node monitors the bus as it
transmits and, consequently, can detect if another node wins arbitration.
Nondestructive and transparent means that messages are not corrupted, and transmission of the highest priority
message is uninterrupted by arbitration. If the bus is active (a node is transmitting or has just finished
transmission), no other nodes will attempt transmission.
If, when the bus is idle (for at least the length of the interframe spacing),and more than one node begins transmission, arbitration occurs transparently and nondestructively.
Nondestructive arbitration means that the node winning arbitration can simply continue transmission of its message without any other node having interfered with the message transmission.