This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TCAN4550EVM: Does the TCAN4550EVM (TCAN4550-Q1) support buses configured with classical CAN?

Part Number: TCAN4550EVM
Other Parts Discussed in Thread: TCAN4550

I am trying to connect to a classical CAN Bus using the TCAN4550EVM, but I am not receiving a CAN message.

I got the version of the board I am using with SPI, but it is 3.2.1 from the following.

address:0x1000 value:0x32150320
address:0x1004 value:0x87654321

The specification says "• Classic CAN Backwards Compatible", so I think I can connect.However, I have not been able to receive the Classical CAN message.

I downloaded TCAN4550 Demo Software and tried to send a message from Kvaser's USB CAN I / F with FDOE of Control Register set to 0, but the reception process does not work.

When receiving in a classical CAN environment, is there a place other than FDOE to change the setting to CAN FD?

  • Hi User,

    Welcome to E2E! 

    TCAN4550 is capable of sending and receiving both classic CAN and CAN FD frames. The default configuration from the demo software should allow reception of classic CAN frames without issue. When receiving a classic CAN frame, this should be evident by the FDF diagnostic flag in the message header. Both types of received frames will be stored in the same FIFO

    • Have you been able to test that TCAN4550 receives a CAN FD frame successfully? I'm curious if this issue is specific to a classic CAN frame.
    • What are the states of the interrupt registers after you send the classic CAN message?
      • If no interrupts are set after the message is sent (nINT LED doesn't assert after message), please check the CAN lines with an oscilloscope so we can confirm that valid levels are being seen by the receiver. If this is the case, can you confirm if other CAN receivers been able to receive CAN frames using this setup?
    • Can you ensure that TCAN4550 is not asleep when this message is sent? The device will automatically timeout a few minutes after startup if it doesn't receive any signals. This can be checked with the status of the INH pin (LED indicates). 

    Please share any other info about your findings or setup that may be relevant to the questions above, and let me know if you have any more questions in the meantime.

    Eric Schott

  • Thank you for your reply.
    I checked the demo software as it is after download with 500k and confirmed that I can receive classic CAN.
    Thank you very much.

    > As for your question, have you tested that the TCAN4550 can receive CAN FD frames successfully? I am wondering if this is a problem specific to classic CAN frames.
    Sorry, I don't have a device that can input/output CAN FD, so I couldn't check.

    > What is the status of the interrupt register after sending a Classic CAN message?
    I confirmed that I was able to receive interrupts with the demo software.

    > If the interrupt is not set after sending the message (nINT LED does not assert after sending the message), please check the CAN line with an oscilloscope to see the valid level at the receiver. In that case, can you check if other CAN receivers were able to receive CAN frames with this setting?
    I have not checked because I was able to receive.

    > Can you confirm that the TCAN4550 is not in sleep mode when this message is sent? After startup, if no signal is received, it will automatically time out after a few minutes. This can be checked by the status of the INH pin (indicated by the LED).
    Even if it does not receive the signal, we have confirmed that it does not receive the signal before it goes into sleep, so we do not think that sleep has any effect on it.
    Sorry, I think my extra fix was the reason why I couldn't receive the classic CAN.

  • Hi,

    Glad to hear you were able to find a solution. Feel free to respond to this thread or create a new one if you have any more questions.

    Eric Schott