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Example of a 500kBit/s high-speed CAN with 11-bit ID (CAN 2.0A) on an engine control unit: | Example of a 500kBit/s high-speed CAN with 11-bit ID (CAN 2.0A) on an engine control unit: | ||
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As you can see, CAN-H and CAN-L are in phase opposition. The advantage is that this eliminates common-mode interference: | As you can see, CAN-H and CAN-L are in phase opposition. The advantage is that this eliminates common-mode interference: | ||
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Usually there are several CAN buses in the vehicle, e.g. CAN drive, CAN comfort and CAN infotainment, | Usually there are several CAN buses in the vehicle, e.g. CAN drive, CAN comfort and CAN infotainment, | ||
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Example of recorded CAN messages (CAN bus sniffing) with Kaufmann Automotive GmbH KCANMonitor: | Example of recorded CAN messages (CAN bus sniffing) with Kaufmann Automotive GmbH KCANMonitor: | ||
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Depending on the speed and bus load of the respective CAN bus, a very large number of messages can accumulate that have to be processed on the bus during " | Depending on the speed and bus load of the respective CAN bus, a very large number of messages can accumulate that have to be processed on the bus during " | ||
- | CAN is used for on-board diagnostics in most vehicles from 2008 onwards with [[obd-2]] protocol. J1939]] is widely used for diagnostics in commercial vehicles and [[NMEA]] in the maritime sector. | + | CAN is used for on-board diagnostics in most vehicles from 2008 onwards with [[obd-2]] protocol. |
At least two nodes must be used for communication on a CAN bus. Since a sent message must be acknowledged by a receiver in the ACK bit, the sending controller sends out an error flag if the message was not properly ACK-checked. | At least two nodes must be used for communication on a CAN bus. Since a sent message must be acknowledged by a receiver in the ACK bit, the sending controller sends out an error flag if the message was not properly ACK-checked. |