Handling traffic on the data highway requires rules and regulations. Just as every driver on an interstate is taught to cede to emergency vehicles, so must there be rules to handle data traffic. When the bus is free, any station can transmit a message. However, if several stations start to transmit simultaneously, bus arbitration awards first access to the message with the highest priority, with no loss of time or data bits. Lower-priority messages are shuffled by order of importance to automatically switch to receive and repeat their transmission attempt the moment the bus is freed up.
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