Data transmission method and system therefor
First Claim
1. In a data transmission system for a vehicle, including a plurality of control systems installed on said vehicle, and a network bus connecting said plurality of control systems with each other for circulating a transmission right through said plurality of control systems to thereby perform transmission of a message between said plurality of control systems,the improvement wherein each one of said plurality of control systems comprises:
- transmitter-receiver means for transmitting data to or receiving data from other ones of said plurality of control systems via said network bus;
transmission failure-detecting means for detecting a failure in transmission of said data;
failure type-identifying means for identifying a type of said failure in transmission of said data;
retransmission control means for determining a maximum number of times of retransmission to be permitted according to said type of failure in transmission identified by said failure type-identifying means, and for causing said transmitter-receiver means to retransmit said data so long as the number of times of retransmission of said data does not exceed the maximum number of times of retransmission to be permitted;
wherein said transmitter-receiver means includes means for transferring the transmission right to another control system when the number of times of failure to retransmit said data exceeds the maximum number of times of retransmission to be permitted;
wherein the failure type-identifying means comprises means for detecting whether an acknowledging response is present, and whether an error in transmission has occurred; and
wherein said transmission failure-detecting means comprises monitoring means for determining that said error in transmission has occurred when data being transmitted does not coincide with data loaded on said network bus.
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Accused Products
Abstract
A data transmission system for a vehicle includes a plurality of control systems installed on the vehicle, and a network bus connecting the plurality of control systems with each other for circulating a transmission right through the plurality of control systems to thereby perform transmission of a message between the plurality of control systems. According to a first aspect, each of the control systems starts transmitting data when it is detected that the transmission right is not generated or lost from the system, and continues transmitting the data when no collision of data transmitted from the present control system with data transmitted from the rest of the plurality of control systems, or when by mediation for avoiding the collision is detected, it is determined to continue data transmission. According to another aspect, the maximum number of times of retransmission to be permitted is determined according to a type of failure in transmission identified, and the retransmission is performed so long as the number times of retransmission of the data does not exceed the maximum number of times of retransmission to be permitted. According to a still another aspect, the message comprises a first response field for receiving a first acknowledging response output from a control system having received the transmission right, and a second response field for receiving a second acknowledging response output from a control system having received data.
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Citations
3 Claims
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1. In a data transmission system for a vehicle, including a plurality of control systems installed on said vehicle, and a network bus connecting said plurality of control systems with each other for circulating a transmission right through said plurality of control systems to thereby perform transmission of a message between said plurality of control systems,
the improvement wherein each one of said plurality of control systems comprises: -
transmitter-receiver means for transmitting data to or receiving data from other ones of said plurality of control systems via said network bus; transmission failure-detecting means for detecting a failure in transmission of said data; failure type-identifying means for identifying a type of said failure in transmission of said data; retransmission control means for determining a maximum number of times of retransmission to be permitted according to said type of failure in transmission identified by said failure type-identifying means, and for causing said transmitter-receiver means to retransmit said data so long as the number of times of retransmission of said data does not exceed the maximum number of times of retransmission to be permitted; wherein said transmitter-receiver means includes means for transferring the transmission right to another control system when the number of times of failure to retransmit said data exceeds the maximum number of times of retransmission to be permitted; wherein the failure type-identifying means comprises means for detecting whether an acknowledging response is present, and whether an error in transmission has occurred; and wherein said transmission failure-detecting means comprises monitoring means for determining that said error in transmission has occurred when data being transmitted does not coincide with data loaded on said network bus. - View Dependent Claims (2)
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3. In a data transmission system for a vehicle, including a plurality of control systems installed on said vehicle, and a network bus connecting said plurality of control systems with each other for circulating a transmission right through said plurality of control systems to thereby perform transmission of a message between said plurality of control systems,
the improvement wherein each one of said plurality of control systems comprises: -
transmitter-receiver means for transmitting data to or receiving data from other ones of said plurality of control systems via said network bus; transmission failure-detecting means for detecting a failure in transmission of said data; failure type-identifying means for identifying a type of said failure in transmission of said data; retransmission control means for determining a maximum number of times of retransmission to be permitted according to said type of failure in transmission identified by said failure type-identifying means, and for causing said transmitter-receiver means to retransmit said data so long as the number of times of retransmission of said data does not exceed the maximum number of times of retransmission to be permitted; and
wherein;the failure type-identifying means comprises means for detecting whether an acknowledging response is present, and whether an error in transmission has occurred; and said retransmission control means sets the maximum number of times of retransmission to be permitted to a larger number when said error in transmission is detected than when no acknowledging response is detected; wherein said transmission failure-detecting means includes monitoring means for determining that said error in transmission has occurred when data being transmitted does not coincide with data loaded on said network bus.
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Specification