Fault localization and health indication for a controller area network
First Claim
1. A method of determining a location of a fault comprising the following steps:
- a) detecting a first error message from a receive line of a node;
b) detecting a second error message from a transmit line of the node;
c) if the first error message is detected before the second error message, determining that the node did not first transmit the second error message; and
, d) if the second error message is detected before the first error message, determining that the node may have first transmitted the second error message.
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Accused Products
Abstract
A node of a network comprises an error message detector arranged to detect error messages transmitted over the network, a counter arranged to count the error messages in order to produce an error message count, and a controller arranged to count valid messages in order to produce a count of valid messages. The controller is arranged to compare the error message count to the valid message count to indicate the health of the network. The node further comprises a transceiver, a controller coupled to the transceiver by a receive line and a transmit line, and error message first logic coupled to the receive and transmit lines. The error message first logic is arranged to detect a first error message from the receive line and a second error message from the transmit line, and to determine whether the node is closest to a fault by comparing timing between the first error message and the second error message.
55 Citations
22 Claims
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1. A method of determining a location of a fault comprising the following steps:
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a) detecting a first error message from a receive line of a node;
b) detecting a second error message from a transmit line of the node;
c) if the first error message is detected before the second error message, determining that the node did not first transmit the second error message; and
,d) if the second error message is detected before the first error message, determining that the node may have first transmitted the second error message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
d1) determining a time difference between the first and second error messages; and
,d2) determining that the node did first transmit the second error message if the time difference is greater than a transceiver delay.
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3. The method of claim 1 wherein step d) comprises the following steps:
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d1) determining a time difference between the first and second error messages; and
,d2) determining that the node did not first transmit the second error message if the time difference is less than a transceiver delay.
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4. The method of claim 3 wherein step d) further comprises the following step:
d3) determining that the node did first transmit the second error message if the time difference is greater than the transceiver delay.
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5. The method of claim 1 further comprising the step of transmitting a message indicating first detection of a fault.
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6. The method of claim 1 further comprising the step of counting a number of times that the node did first transmit the second error message.
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7. The method of claim 6 wherein step d) comprises the following steps:
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d1) determining a time difference between the first and second error messages; and
,d2) determining that the node did first transmit the second error message if the time difference is greater than a transceiver delay.
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8. The method of claim 6 wherein step d) comprises the following steps:
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d1) determining a time difference between the first and second error messages; and
,d2) determining that the node did not first transmit the second error message if the time difference is less than a transceiver delay.
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9. The method of claim 8 wherein step d) further comprises the following step:
d3) determining that the node did first transmit the second error message if the time difference is greater than the transceiver delay.
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10. The method of claim 6 further comprising the step of transmitting a message indicating the number.
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11. A node comprising:
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a transceiver coupled to a communication line;
a controller coupled to the transceiver by a receive line and a transmit line; and
,error message first logic coupled to the receive and transmit lines, wherein the error message first logic is arranged to detect a first error message from the receive line and a second error message from the transmit line, and wherein the error message first logic is arranged to determine whether the node is closest to a fault by comparing timing between the first error message and the second error message. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification