Multiplex transmission system for vehicles having a failure diagnosis function
First Claim
1. A multiplex transmission system for vehicles having a multiplex transmission path formed in the form of a ring and a plurality of communication nodes connected to the multiplex transmission path in order to communicate information for controlling a vehicle with the other nodes, comprising:
- said plurality of communication nodes having respective reception confirmation signal output circuits each of which outputs a reception confirmation signal on the transmission path when a predetermined diagnosis signal is received from said multiplex transmission path;
transmission path interruption means for interrupting ring formed by the transmission path at any one place of said multiplex transmission path so that said multiplex transmission path may have first and second ends thereof;
first transceiving means for outputting a first diagnosis signal on the interrupted transmission path from the first end of the interrupted transmission path and for receiving a first reception confirmation signal from each of said plurality of communication nodes in response to the first diagnosis signal;
second transceiving means for outputting a second diagnosis signal on the interrupted transmission path from the second end of the interrupted transmission path and for receiving a second reception confirmation signal from each of said plurality of communication nodes in response to the second diagnosis signal; and
diagnosis means for diagnosing the position of a line disconnection in said transmission path or a defective node, on the basis of the reception communication signals received by said first and second transceiving means.
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Accused Products
Abstract
In a multiplex transmission system for vehicles a transmission path is made usually in the form of a loop, where one master-like supervisory node and a plurality of slave-like ordinary nodes are connected to the path. During diagnosis, this transmission path is interrupted, thus interrupting the loop. On the interrupted transmission path, the master supervisory node causes a diagnostic signal to flow in the two directions of the transmission path. The supervisory node pinpoints the position of a line disconnection in the transmission path on the basis of a reception confirmation signal received regarding respective directions from each of the ordinary nodes.
29 Citations
12 Claims
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1. A multiplex transmission system for vehicles having a multiplex transmission path formed in the form of a ring and a plurality of communication nodes connected to the multiplex transmission path in order to communicate information for controlling a vehicle with the other nodes, comprising:
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said plurality of communication nodes having respective reception confirmation signal output circuits each of which outputs a reception confirmation signal on the transmission path when a predetermined diagnosis signal is received from said multiplex transmission path; transmission path interruption means for interrupting ring formed by the transmission path at any one place of said multiplex transmission path so that said multiplex transmission path may have first and second ends thereof; first transceiving means for outputting a first diagnosis signal on the interrupted transmission path from the first end of the interrupted transmission path and for receiving a first reception confirmation signal from each of said plurality of communication nodes in response to the first diagnosis signal; second transceiving means for outputting a second diagnosis signal on the interrupted transmission path from the second end of the interrupted transmission path and for receiving a second reception confirmation signal from each of said plurality of communication nodes in response to the second diagnosis signal; and diagnosis means for diagnosing the position of a line disconnection in said transmission path or a defective node, on the basis of the reception communication signals received by said first and second transceiving means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification