说明：  CANOpen协议是欧洲汽车行业中，CAN总线的统一应用层标准，提供了详尽的描述，非常适合于CAN总线的应用层开发！
(CANOpen agreement in the European automotive industry, CAN bus is a unified application-layer standards, provides a detailed description, very suitable for CAN bus application-layer development!)