| 摘要 |
A communication system has a number of nodes connected to a serial data bus. Nodes communicate with each other by transmitting dominant and recessive bits during bit intervals as taught by CAN (controller area network) arbitration protocol. According to the CAN arbitration protocol, any dominant bit transmitted during a bit interval causes the bit value received to be a dominant bit regardless of the number of recessive bits being sent. The system is arranged so that two or more nodes each respond to a report query message sent by one of the nodes, with a report message sent simultaneously by each of the nodes. The headers (leading bits) of each of the report messages sent by nodes responding to a report query message are the same, allowing arbitration on a trailing node data field. This results in the message having the numerically largest (or smallest) node data field value to survive arbitration. Thus a number of nodes can be polled with a report query message and will respond by simultaneously sending each node's numerical data value with the largest or smallest of these data values received by the system's nodes. |
