MQB-sniffer for Volkswagen Golf MK7
电动汽车上CAN报文解析
常用车辆CAN总线通讯协议，大多直接采用SAE-J1939的形式制定。电动汽车首先遇到了电池系统，电机系统等新加入电气需要重新设定PGN码等问题。CAN协议始终处在诸侯割据的状态。在过去的几年中，国家及相关机构也一直在对电动汽车的CAN通讯协议进行研究，希望形成统一的协议体系。统一的CAN协议，首先是零部件供应商的福音。当前主流主机厂，每家都有自己的整车通讯协议，各个供应商，需要根据整车厂的定义，修改零部件的CAN协议。
制定电动汽车的CAN协议，基本的思路是在SAE-J1939的基础上，根据自身电动汽车的需求，做出必要的调整。
ISO 11898-2003 download
NXP S32K146 Evaluation Board
CAN Network layer from ISO 15765-4
Network Iayer interface and Standardized diagnostic CAN identifiers from 15765-3
8.Standardized diagnostic CAN identifiers
Mapping of the N_PDU fields - from ISO15765-2
Addressing formats
The exchange of network layer data is supported by three addressing formats: normal, extended and mixed addressing. Each addressing format requires a different number of CAN frame data bytes to encapsulate the addressing information associated with the data to be exchanged. Consequently, the number of data bytes transported within a single CAN frame depends on the type of addressing format chosen.
The following (7.3.2 to 7.3.5) specifies the mapping mechanisms for each addressing format, based on the data link layer services and service parameters defined in ISO 11898-1.
ISO 15765-2
Road vehicles — Diagnostics on Controller Area Networks (CAN) —
Part 2:Network layer services : ISO 15765-2:2004(E)
J1939协议与CAN2.0对应关系图表
CAN2.0是一种总线规范，是数据链路层的技术。J1939是SAE（美国汽车协会）定义的基于CAN总线的规范，目的是解决不同发动机厂商、不同ECU厂商的兼容性问题。