Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

CAN bus protocol counter REC/TEC



  • Hi everyone,

    I would like to know where are this counters and how I can recover there value in Qt CAN class .

    Thank you
    Martial



  • I have found my answer in the CAN protocol here : https://en.wikipedia.org/wiki/CAN_bus

    in fact, when problem occur, node send active frame, after 127 active frame , if error is still here, node send passive error frame, and after 255 , node place in mode buss off.

    So we just need to check this type of frame and the type of enum return from Qt lib when we are in mode bus off :

    QCanBusDevice::CanBusStatus QCanBusDevice::busStatus() const
    

    Bye

    edit:
    In fact this is not 127 frame send, because counter increase by 8 bit when error occur but is when counter are 127, node emit passive frame...


Log in to reply