CAN node state transition

In CAN communication, a CAN node may be in three states: active error state, passive error state, and bus-off state. When an error occurs in the active error state, the CAN node sends an error frame. When the send error counter or the receive error counter is greater than 127, the CAN node will enter the passive error state and send an error frame. When the send error counter is greater than 255, the CAN node will enter the bus-off state and leave the CAN bus without affecting the communication of other CAN nodes.