说明：  The CAN network is not only used for diagnostic application, the goal of the first use of this network is to carry out the intersystem communications, the related message set don t comply with the specification established in this document. Thus these 2 types of application shall be able to cohabit on the bus without trouble. Closely links are made between documents related to both application. Although this specification is written to meet the diagnostic application requirements, the scheme of message segmentation can be apply to another application involving messages with more than 7 data bytes. This document does not specify any requirement for legislated on board diagnostic "OBD" purpose. Refer to the ISO document [REF 5] for its implementation in the emission-related systems. No restriction , no specific implementation is allowed, full compliance with the standard is requisite