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LIN collision detection

Simona

Hi,

sorry, I don't know if I'm in the right section.

I have a question about the LIN capability detection of a collision.

I studied the specification 2.2. I understood HOW the master MANAGES a collision in case of event triggered frame. But I do not understand HOW the master KNOWS that a collision occurs. 
If we suppose that two slaves send a response, only the slave that has lost the arbitration knows it. In fact this slave sees in the bus different bits than those he injected. Perhaps this slave is able to send an error message?

Please, can you help me?

Thanks

  • 0

    The collision is supposed to be caught by the master, based on the one of the checksums ending up wrong.  Optimally the frame IDs of the set of event-triggered frames would be selected such that any combination would already invalidate the PID.

  • 0 in reply to Broeker

    Hi Broeker, Thanks you very much for your answer. I'm not sure I understood correctly, so I repeat you my understanding. 

    1. The Master sends the Event-triggered Header
    2. Slave #1 and Slave  #2 receive the Header and send their response
    3. Suppose that Slave #2 lost the arbitration. Question: Does Slave#2 stop transmission?
    4. The Master receives
      1. the Slave#1 responce if Slave#2 stops his transmission. In this case how the Master understand the collision?
      2. the dominant voltage of the two responses with the wrong CRC (if Slave#2 do not stop his transmission). So the master understand that a collision occurs.

    Thanks

    Simona

  • 0
    Simona said:
    I don't know if I'm in the right section.

    I think not!

    LIN is a network protocol:

    https://en.wikipedia.org/wiki/Local_Interconnect_Network

    It has nothing to do with Keil or ARM.