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TCAN4550EVM: ACK with WUF enabled receiver

Part Number: TCAN4550EVM


We are trying to design a new CAN-FD based partial-network test bench.

I understand that when we try to send a CAN message which is not matching with WUF masked ID to sleeping network, it is normal to occur no-ACK error for sender ECU. 

What I want to ask is, does no-ACK error also occur if we send a CAN message which is matching with WUF masked message ID, but not matching with non of recievers data field mask?

In other words, does reciver tranciever do ack to WUF message that match with ID mask, but not matching with data field mast?

Thank you

Best regards,

  • Sangwoo,

    To make sure I understand the question, you're asking if a WUF receiver ACKs a WUF that matches the ID mask, but not the data mask, is that correct? In my understanding, if a device is in sleep mode and waiting for a WUF, even if that WUF is correct, it will not send an ACK bit to the bus.

    Please let me know if my understanding of your question was correct.


    Eric Hackett 

  • Yes, that was the my question!

    This is my understanding scenario for WUF wake up based on your answer, 

    1) Even WUF message match with masking, that WUF message itself would cause no-ACK to Tx ECU
    2) But Rx ECU soon wake up from sleep mode since WUF was correct
    3) Rx ECU will ACK to next Tx message from the Tx ECU.
    4) That ACK will clear the no-ACK counter in Tx ECU.

    If I misundertood something, Please let me konw.

    thank you very much, It was great help for us.


  • Sangwoo,

    That is all correct. If you have any other questions please don't hesitate to ask.


    Eric Hackett