When the first versions of SAE J1939 emerged in the late 1980s and early 1990s, the objective was straightforward: provide a standardized communication protocol for electronic control units (ECUs) in heavy-duty trucks. At the time, vehicle manufacturers were rapidly increasing the number of electronic subsystems, creating a need for a…
Posts tagged as “CAN Bus”
If you’ve worked with SAE J1939 long enough, you’ve probably experienced the frustration of connecting two devices to a CAN bus and seeing… absolutely nothing happen. No engine data. No diagnostic messages. No responses to requests. Just silence. The good news is that most J1939 communication problems are caused by…
In previous quick demos, we focused on SAE J1939 parameters that are transmitted periodically, such as engine speed, vehicle speed, fuel level, and engine temperatures. These messages are broadcast automatically at predefined intervals, allowing any node on the network to receive the data without explicitly asking for it. The Vehicle…
Engine speed is one of the most frequently monitored parameters in any SAE J1939 network. Whether you are developing a dashboard, testing an engine ECU, validating telematics software, or learning how J1939 communication works, engine speed is often the first parameter engineers look at. In this post, we will explain…
If you are new to SAE J1939 development, you may believe that access to a truck, engine, generator, or agricultural machine is required before you can write any meaningful software. While eventually you will want to test your application on real equipment, the majority of J1939 software development can be…
Modern digital dashboards are amazing. They offer colorful displays, engine diagnostics, fuel consumption data, trip information, and customizable gauges that make a 20-year-old truck feel like a brand-new vehicle. Unfortunately, many truck owners discover a frustrating reality after installation: The dashboard powers up perfectly, but no engine data appears on…
As heavy-duty vehicles become increasingly connected, engineers are looking for ways to integrate vehicle data into fleet management systems, cloud applications, industrial control systems, and enterprise databases. The hardware needed for such integrations is readily available. Products from companies such as Red Lion, Moxa, HMS, Sierra Wireless, and many others…
One question that appears regularly in SAE J1939 discussions is whether multiple Electronic Control Units (ECUs) can transmit the same Parameter Group Number (PGN). At first glance, the answer seems straightforward: if the J1939 standard defines a message, why shouldn’t multiple devices be allowed to transmit it? In reality, the…
For engineers working with agricultural machinery, one question comes up repeatedly: “Is ISOBUS just another name for J1939?” The short answer is: Almost—but not quite. Both protocols share the same technical roots, use the same physical CAN bus technology, and exchange messages using Parameter Group Numbers (PGNs). In fact, a…
One of the questions that recently crossed my mind was whether our existing SAE J1939 gateways and monitoring tools could be useful in the agricultural sector, specifically for monitoring ISOBUS networks. The short answer appears to be: Yes, in many cases they can. The longer answer is a bit more…
