SAE規格 J2602-1, 2021: (R) LIN Network for Vehicle Applications

Description

This document covers the requirements for SAE implementations based on ISO 17987:2016. Requirements stated in this document will provide a minimum standard level of performance to which all compatible ECUs and media shall be designed. This will assure full serial data communication among all connected devices regardless of supplier.

The goal of SAE J2602-1 is to improve the interoperability and interchangeability of LIN devices within a network by adding additional requirements that are not present in ISO 17987:2016 (e.g., fault tolerant operation, network topology, etc.).

The intended audience includes, but is not limited to, ECU suppliers, LIN controller suppliers, LIN transceiver suppliers, component release engineers, and vehicle system engineers.

The term “master” has been replaced by “commander” and term “slave” with “responder” in the following sections.

Mission/Theme
This serial data link layer network is intended for use in applications where high data rate is not required and a lower data rate can achieve cost reductions in both the physical media components and in the microprocessor and/or dedicated logic devices (ASICs) which use the network.

Overview
LIN is a single wire, low cost, class A communication protocol. LIN is a commander-responder protocol, and utilizes the basic functionality of most universal asynchronous receiver transmitter (UART) or serial communication interface (SCI) devices as the protocol controllers in both commander and responder-nodes. To meet the target of “lower cost than either an OEM proprietary communications link or CAN link” for low speed data transfer requirements, a single wire transmission media based on the ISO 9141 specification was chosen. The protocol is implemented around a UART/SCI capability set, because the silicon footprint is small (lower cost). Many small microprocessors are equipped with either a UART or SCI interface (lower cost), and the software interface to these devices is relatively simple to implement (lower software cost). Finally, the relatively simplistic nature of the protocol controller (UART/SCI) and the nature of state-based operation, enable the creation of application specific integrated circuits (ASICs) to perform as input sensor gathering and actuator output controlling devices, in the vein of mechatronics.

All message traffic on the bus is initiated by the commander-node. Responder-nodes receive commands and respond to requests from the commander-node. Since the commander-node initiates all bus traffic, it follows that the responder-nodes cannot communicate unless requested by the commander-node. However, responder-nodes can generate a bus wakeup, if their inherent functionality requires this feature.

The LIN Consortium developed the set of LIN specifications. The Consortium was a group of automotive OEMs, semiconductor manufacturers, and communication software and tool developers. The LIN specification set is no longer available through the LIN Consortium. Instead, it has been converted to a series of ISO 17987 specifications.

The LIN specifications contain more than just a definition of the LIN protocol and physical layer. In addition, a work flow process, diagnostics and configuration methods, definition of an application program interface (API), file structures for a node capability file (NCF) and a LIN description file (LDF), and semantics are identified as required (mandatory in all implementations). However, since there is a great deal of flexibility in the protocol and physical layer, applicability of these specifications to SAE J2602-1 networks will be further specified in this document.

Relationship to the LIN Specifications

As described in the LIN specification package, the ISO 17987:2016 protocol specification suite consists of seven standards:

ISO 17987-1 - Road Vehicles - Local Interconnect Network (LIN) - Part 1 - General Information and Use Case Definition

This document gives an overview of the structure and the partitioning of ISO 17987 (all parts). In addition, it outlines the use case where the ISO 17987 (all parts) will be used. The terminology defined in this document is common for all LIN communication systems and is used throughout ISO 17987 (all parts). This document has been established in order to define the use cases for LIN.

ISO 17987-2 - Road Vehicles - Local Interconnect Network (LIN) - Part 2 - Transport Protocol and Network Layer Services

This document specifies a transport protocol and network layer services tailored to meet the requirements of LIN‑based vehicle network systems on local interconnect networks. The protocol specifies an unconfirmed communication.

ISO 17987-3 - Road Vehicles - Local Interconnect Network (LIN) - Part 3 - Protocol Specification

This document specifies the LIN protocol including the signal management, frame transfer, schedule table handling, task behavior and status management and LIN master and slave node. It contains also OSI layer 5 properties according to ISO 14229-7 UDS on LIN-based node configuration and identification services (SID: B016 to B816) belonging to the core protocol specification.

ISO 17987-4 - Road Vehicles - Local Interconnect Network (LIN) - Part 4 - Electrical Physical Layer (EPL) Specification 12 V and 24 V

This document specifies the 12 V and 24 V electrical physical layers (EPL) of the LIN communications system. The electrical physical layer for LIN is designed with bit rates up to 20 kbit/s. The medium that is used is a single wire for each receiver and transmitter with reference to ground. This document includes the definition of electrical characteristics of the transmission itself and also the documentation of basic functionality for bus driver devices.

ISO /TR 17987-5 - Road Vehicles - Local Interconnect Network (LIN) - Part 5 - Application Programmers Interface (API)

This document specifies the LIN application programmers interface (API) and the node configuration and identification services. The node configuration and identification services are specified in the API and define how a slave node is configured and how a slave node uses the identification service.

ISO 17987-6 - Road Vehicles - Local Interconnect Network (LIN) - Part 6 - Protocol Conformance Test Specification

This document specifies the LIN protocol conformance test. This test verifies the conformance of LIN communication controllers with respect to ISO 17987-2 and ISO 17987-3. This document provides all necessary technical information to ensure that test results are identical even on different test systems, provided that the particular test suite and the test system are compliant to the content of this document.

ISO 17987-7 - Road Vehicles - Local Interconnect Network (LIN) - Part 7 - Electrical Physical Layer (EPL) Conformance Test Specification

This document specifies the 12 V and 24 V electrical physical layers (EPL) of the LIN communications system. The electrical physical layer for LIN is designed with bit rates up to 20 kbit/s. The medium that is used is a single wire for each receiver and transmitter with reference to ground. This document includes the definition of electrical characteristics of the transmission itself and also the documentation of basic functionality for bus driver devices

The remainder of this document (SAE J2602-1) will directly reference these LIN specifications (publication date: 2016).