In my application I have to receve 24 message id (standard format) . I supposed to assing some message to a Message object and all the other to 15 object. I do not know if this solves my problem, but however if I do: CanGetMOId, I get 0x1fffffff then I call CanSetMOId to a vaule, calling CanGetMOId I get 0x1fffffff againg . And all RX Message are waken-up with the mask of the lowest index of the MO I define as RX ??