物理层，250 Kbps，非屏蔽双绞线（UTP

[中文适用范围]： 本文档描述了一种物理层，该物理层利用非屏蔽双绞线 (UTP) 电缆和延长的短截线长度，从而为 ECU 放置和网络拓扑提供灵活性。此外，未指定连接器。现在可以使用支持新推出的 CAN 灵活数据速率帧格式（称为“CAN FD”）的 CAN 控制器。这些控制器在 SAE J1939-15 网络上使用时，必须限制为仅使用符合 ISO 11898-1 (2003) 的经典帧格式。这些 SAE 建议做法适用于轻型和重型公路或越野车辆以及使用车辆衍生部件（例如发电机组）的适当固定应用。感兴趣的车辆包括但不限于：公路和非公路卡车及其拖车；建筑设备；以及农业设备和农具。 [外文原描述]： This document describes a physical layer utilizing Unshielded Twisted Pair (UTP) cable with extended stub lengths for flexibility in ECU placement and network topology. Also, connectors are not specified.CAN controllers used on SAE J1939-15 networks must be restricted to use only Classical Frames as defined in ISO 11898- 1. A network which may have legacy controllers cannot tolerate FD Frames.These SAE Recommended Practices are intended for light- and heavy-duty vehicles on- or off-road as well as appropriate stationary applications which use vehicle derived components (e.g., generator sets). Vehicles of interest include, but are not limited to: on- and off-highway trucks and their trailers; construction equipment; and agricultural equipment and implements.Cross Reference: ISO11898,J1128_201512,J1939/11_201612,J1939/13_201610