CAN bus: Difference between revisions
No edit summary |
|||
| Line 16: | Line 16: | ||
===CAN IDs=== | ===CAN IDs=== | ||
Lower IDs have priority over higher IDs | Lower IDs have priority over higher IDs. 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: | ||
* If multiple ECUs are transmitting at the same cycle, all must transmit recessive, or everyone will see dominant | |||
* Transition to dominant is slower than transition from dominant | |||
* Synchronization begins on the first recessive to dominant transition after an idle period ("start bit" of frame) | |||
* Resynchronization occurs on each subsequent recessive to dominant transition | |||