CAN bus: Difference between revisions
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* PCA82C252/TJA1054A -- 125Kbit, highly tolerant of 11898 cable fault modes, very low EM emissions, single-wire capability (33.3Kbit/s) | * PCA82C252/TJA1054A -- 125Kbit, highly tolerant of 11898 cable fault modes, very low EM emissions, single-wire capability (33.3Kbit/s) | ||
* MC33897/AUS5790 -- 33.33 or 83.33Kbit/s single-wire CAN | * MC33897/AUS5790 -- 33.33 or 83.33Kbit/s single-wire CAN | ||
Nodes, especially e.g. sensors, typically send their state in Data Frames on a regular period. | |||
===CAN IDs=== | ===CAN IDs=== | ||
Lower IDs have priority over higher IDs, and form the 11-bit "Arbitration Field" in a CAN frame (there are 2 such fields in an Extended Frame, one of 11 and one of 18 bits, separated by two bits). While transmitting a message, each ECU must also listen. If it sees a 0 while sending a 1, it must cease to transmit until the current message ends. Logical 0 is the "dominant" signal: | Lower IDs have priority over higher IDs, and form the 11-bit "Arbitration Field" in a CAN frame (there are 2 such fields in an Extended Frame, one of 11 and one of 18 bits, separated by two bits). While transmitting a message, each ECU must also listen. If it sees a 0 while sending a 1, it must cease to transmit until the current message ends. Logical 0 is the "dominant" signal: | ||