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February 8, 2008 BAE 5030 1
In-Vehicle Networking
Lecture 4 Introduction to SAE J1850
BAE 5030 - 003
Fall 2008
Instructor: Marvin Stone
Biosystems and Agricultural Engineering
Oklahoma State University
February 8, 2008 BAE 5030 2
SAE J1850 Overview - History
• Developed as a network protocol for use in automobiles
– Driven by:
• Distributed controllers for engine, trans., instrumentation, etc.
• Need to reduce wiring cost
• Need for centralized diagnostics
• Requirements for single point emissions diagnostics
• Proprietary networks developed
– Chrysler
• SCI (Serial Communications Interface)
– Motorola SCI port, 62.5 kbps.
– A dedicated high-speed link between an engine controller and off-board test
equipment.
• CCD (Chrysler Collision Detection)
– Used in Deere tractors in the 1990s (7812.5 bps)
– GM – ALDL (Assembly Line Diagnostic Link)
• AKA 8192 UART
– Ford - ACB / ACP (Audio Control Bus or Protocol)
• Remote control of entertainment equipment.
– Others
• Recommended practice in 1987, “the” class B protocol in 1994
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