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SAE J1708 - Serial Data Communications Between Microcomputer Systems in Heavy-Duty Vehicle Applications

This Fact Sheet was written on October 01, 2005. The status of the standard at the time was: Published in August 2004.

This Fact Sheet was last verified on October 14, 2009

 Check the ITS Standards Search to see if there has been subsequent development activity.

Overview

This standard, SAE J1708 - Serial Data Communications Between Microcomputer Systems in Heavy-Duty Vehicle Applications, defines a recommended practice for implementing a bi-directional, serial communication link among modules containing microcomputers. The primary focus of the standard is on heavy-duty vehicles, namely, transit buses and commercial vehicles such as trucks. This document defines those parameters of the serial link that relate primarily to hardware and basic software compatibility such as interface requirements, system protocol, and message format.

The goals of the organization that developed this document included:

Minimization of hardware cost and overhead;

Flexibility for expansion and technological advancements with minimum hardware/software impacts on in-place assemblies;

Utilization of widely accepted electronics industry standard hardware and protocols for flexibility in parts selection;

Provision of a high degree of electromagnetic compatibility; and

Provision of flexibility to allow customization for product individuality and proprietary considerations.

What are these standards for?

The purpose of this document is to define a general-purpose serial data communication link that may be utilized in heavy-duty vehicle applications. It is intended to serve as a guide to promote serial communication compatibility among microcomputer-based modules.

Who uses them?

This standard, SAE J1708 - Serial Data Communications Between Microcomputer Systems in Heavy-Duty Vehicle Applications, is intended for use by system and communications engineers, designers, developers, and users of ITS systems, as well as those interested in communications technologies and practices for public transit and commercial vehicle operations.

How are they used?

The primary use of this standard is to guide the design of systems that allow electronic modules that contain microcomputers to share data, thereby cost effectively enhancing their operation. Systems that require a dedicated communication link between modules to implement a specific function may require the use of other standards.

Scope

This standard, SAE J1708 - Serial Data Communications Between Microcomputer Systems in Heavy-Duty Vehicle Applications, defines the interface requirements and connecting devices necessary for the transmission of signals and information among electronic components in trucks and buses.

The following standards and documents, while not part of the ITS standards, should be considered when using this standard:

• SAE J1455 – Electronic Equipment Design (Heavy-Duty Trucks)
• SAE J1587 – Electronic Data Interchange Between Microcomputer Systems in Heavy-Duty Vehicle Applications
• SAE J1922 – Powertrain Control Interface for Electronic Controls Used in Medium and Heavy-Duty Diesel On-Highway Vehicle Applications
• SAE J2497 -- Power Line Carrier Communications for Commercial Vehicles
• TIA/EIA-485-A-98, Electrical Characteristics of Generators and Receivers for Use in Balanced Digital Multipoint Systems

How to obtain Standards

• https://www.sae.org/ Phone: 877-606-7323
  

Society of Automotive Engineers 1-877-606-7323 https://www.sae.org/