SAE規格 J2602-2, 2021: (R) LIN Network for Vehicle Applications Conformance Test

Description

This document covers the tests to be performed on all SAE J2602-1 (2021 revision) devices. Tests described in this document will ensure a minimum standard level of performance to which all compatible electronic control units (ECUs) and media shall be designed. This will assure full serial data communication among all connected devices regardless of supplier.

The goal of SAE J2602-2 is to improve the interoperability and interchangeability of LIN devices within a network by verifying the devices pass a minimum set of tests.

To allow for easy cross-reference, this document is arranged such that the conformance test for a given section in SAE J2602-1 (2021 revision) is in the same section in SAE J2602-2.

This document is to be referenced by the particular vehicle original equipment manufacturer (OEM) component technical specification that describes any given ECU in which the LIN data link controller and physical layer interface is located. Primarily, the performance of the physical layer is specified in this document. ECU environmental and other requirements, when provided in the component technical specification, shall supersede the requirements of this document.

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The term “master” has been replaced by “commander” and term “slave” with “responder” in the following sections.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 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 controller area network (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 conformance test specifications contains tests for the physical layer, data link layer, node configuration, and network management.

Relationship to the LIN Conformance Test Specification

This document includes complete information for testing SAE J2602-1 (2021 revision) compliant devices. ISO 17987 is referenced only for optional behaviors not defined in SAE J2602-1.