A Brief Explanation of CAN Bus

- May 22, 2019-

What is CAN Bus Technology?

As automobiles and other vehicles have become more environmentally friendly and more technologically advanced, it has become increasingly important to have a central networking system. This system connects all the modules working throughout the vehicle so that they can work together to run effectively and efficiently; for example, the engine reports the vehicle’s speed to the transmission, which in turn must tell other modules when to shift gears. Connecting all these individual modules to each other became too complex, so a central networking system became necessary to efficiently run the vehicle. The Controller Area Network, or CAN bus, is one of these central networking protocols used in vehicles without a host computer.

A Brief History of CAN Bus

Robert Bosch GmbH, a German engineering and electronics company with an emphasis on the automotive industry, began work on the CAN bus protocol in 1983 before releasing it at the Society of Automotive Engineers congress in 1986. The company promoted the manufacture of the BMW 850 coupe that year as the first vehicle featuring the CAN bus system. Since the wiring of the electronics in the vehicle was drastically reduced thanks to the introduction of CAN bus, the coupe itself weighed over 100 pounds less than previous models of the automobile, and the sensors worked significantly faster.

Since that time, the Society of Automotive Engineers has required that 100 percent of all automobiles sold in the United States be outfitted with the CAN bus protocol since 2008, and a similar mandate has been instituted in Europe.

The Benefits of CAN Bus

In addition to creating lighter vehicles, the CAN bus protocol has many other significant benefits. By connecting all the modules in a vehicle to one central line, the control system is simplified and more easily regulated. This design allows any connected module to alert the main controller to an event that as it occurs which will cause the rest of the system to respond accordingly. The shared data line allows multiple modules to be attached with less invasive efforts, making the potential for error much lower.

If one module on the CAN bus fails, it does not necessarily cause the failure of other modules. Unless the two systems are directly related and one cannot run without the other, the healthy modules will continue to function perfectly despite the loss of one bad module. This makes the entire system safer.

Additionally, diagnostics of the vehicle are simpler and more specific due to the specialized and self-contained nature of the modules. Diagnostics can now pinpoint the exact cause of the module failure with accuracy and speed. When one module needs maintenance, that module can simply be targeted and replaced rather than tearing apart the entire vehicle.

One of the most significant benefits of CAN bus technology is the ratio it offers of price to performance. Currently CAN bus is one of the most affordable network systems in addition to being one of the most reliable, making it the main cost-effective choice of automobile manufacturers around the world.

CAN bus offers a simple interface for attaching an additional node. The node can be used for diagnostics, reprogramming, monitoring, and more. Many tools have been created to tie into the CAN bus. Currently, there are solutions to do USB to CAN, wireless to CAN, PCIx to CAN, and even a CAN bus logger.

The Application of CAN Bus

Although the CAN bus protocol was introduced for automotive use, today the system is used in several other networking applications. With the simple system of networking individual modules into a single central line of control, many companies are taking advantage of the CAN bus protocol in assembly lines, industrial vehicles, medical machinery and any other machinery that uses multiple modules that must communicate with each other.

Autonomous industrial machinery, as well as mobile machines, have been increasingly integrating CAN bus protocol because of the embedded control in the system. Based on the reliability and efficiency of the protocol, medical and military equipment have also seen a rise in the application of CAN bus. As machinery becomes increasingly complex, the application of the CAN bus system is likely to rise with the technology.