If you have recently started working with SAE J1939, chances are your search history looks something like this: How do I monitor J1939 traffic? What hardware do I need for J1939 development? How do I simulate a J1939 ECU? How can I test my software without connecting to a real…
Posts tagged as “heavy-duty vehicle networks”
One of the more common questions when analyzing or simulating SAE J1939 traffic is surprisingly simple: “How accurate must a J1939 message frequency be?” If a message is supposed to be transmitted every 100 milliseconds, does that mean exactly 100 milliseconds? Can it be 101 milliseconds? 105 milliseconds? What happens…
When people talk about SAE J1939, they often jump straight to CAN frames, PGNs, or diagnostic trouble codes. But all of those live downstream from the most important part of the standard: the application layer. The application layer is where J1939 stops being a transport mechanism and becomes a language.…
In the late 1980s and 1990s, heavy-duty vehicles (like diesel trucks and buses) began using electronic networks to share data among engine, transmission, brake, and other control units (ECUs). The industry’s first standardized solution was a combination of SAE J1708 and SAE J1587. In this two-part system, J1708 defined the…
