• State Not Answered
  • Locked Locked
  • Replies 18 replies
  • Subscribers 21 subscribers
  • Views 10714 views
  • Users 0 members are here
2025 survey

We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.

Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

CAN Node ID

Sundeep Kokkonda

Please answer me:

1. What is the difference between CAN Node ID & CAN Message ID? How the CAN Node ID helpful in Communication?

Parents
  • 0 in reply to Sundeep Kokkonda

    The CAN controller doesn't give a hoot about any protocol used. It just performs whatever ID filtering it supports based on whatever standard it supports. Then it hands over accepted frames and leaves it 100% to the source code to decide what to do next.

    Some protocols and some CAN controllers makes it easy to set up the required filtering in hardware. Some protocols/CAN controllers means you have to let the controller accept lots of frames and let the software do further filtering.

Reply
  • 0 in reply to Sundeep Kokkonda

    The CAN controller doesn't give a hoot about any protocol used. It just performs whatever ID filtering it supports based on whatever standard it supports. Then it hands over accepted frames and leaves it 100% to the source code to decide what to do next.

    Some protocols and some CAN controllers makes it easy to set up the required filtering in hardware. Some protocols/CAN controllers means you have to let the controller accept lots of frames and let the software do further filtering.

Children
  • 0 in reply to ImPer Westermark

    What CAN controller are you using?
    Does it's documentation mention UDS?

    The CAN controller likely just filters on CAN message ID, and expects YOUR software/stack to do the other work.

  • 0 in reply to Westonsupermare Pier

    ( I am not a native English speaker. )

    There are several CAN devices on a CAN-Bus.
    Device-A, Device-B, Device-C.

    Device-A is configured to only receive CAN-Messages with CAN-IDs 0xA10, 0xA50;
    Device-B is configured to only receive CAN-Messages with CAN-IDs 0xB10, 0xB50, 0xB70;
    Device-C is configured to only receive CAN-Messages with CAN-IDs 0xC10, 0xC50, 0xC90;

    So there are CAN-Nodes:
    A-0xA10, A-0xA50,
    B-0xB10, B-0xB50, B-0xB70,
    C-0xC10, C-0xC50, C-0xC90.

    TP Layer (ISO-15765) is responsible to deliver UDS (ISO-14229) Data from one device to another, even the UDS data is more than 8 bytes.

    DS Layer is on the top of TP Layer.

    Device-A:
    A-0xA10 for receiving Runtime data.
    A-0xA50 for receiving UDS data. (Runtime Diagnostic is possible)

    When Device-C wants to send UDS data to Device-A, it sends the UDS data (100 Bytes) with CAN-ID 0xA50 via TP Layer (more than 100 Bytes). Once Device-A's TP Layer receives the UDS data (more than 100 Bytes), TP Layer passes the UDS data (100 Bytes) to it's DS Layer. Device-A's DS Layer then analyzes the UDS data, fetches the Service-ID......

  • 0 in reply to John Linq

    For automotive, in the real world, the UDS solution is decided by Car manufacturers, and controlled by very less solution providers. Since you have CANoe, I believe you should have a better way to learn UDS and ISO 15765-2.

  • 0 in reply to John Linq

    Is it possible that one ECU will request another ECU for diagnostic data using Services? I think it is not possible. Tester needs to send Diag services for diagnosing the ECU. One ECU can't diagnose other ECU.

    Please let me know does CAN ID '0' is valid or not?