What the heck is CAN Bus? 

You ask Google the question “what is CAN Bus (Controller Area Network System) and it will say this: “A robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other’s applications without a host computer.”

At the start of my career, this is how I would have explained the system to clients, however it left many looking like this:


It is safe to say that this is not a particularly palatable description of such an integral part of modern transport, so I am going to try and translate this into plain English, and I will be doing it in the way of an analogy.

Just as your body’s central nervous system acts as the connector between all the parts of your body, facilitating the communication necessary for you to walk, run, jump, eat, sing and swim, so too does the CAN Bus system facilitate the communication between a machine’s parts to allow arms to move, rotors to turn, pistons to shoot and airbags to deploy.

It is this system, which has changed the ways in which ECUs communicate. Its simplicity and reliability have made it the industry standard for all vehicles and machinery, big and small. From your average Hyundai Getz to the A380 in the sky, CAN Bus systems are ubiquitous in the transport industry.

However, before CAN Bus, a much far less reliable system was in place. The old-school method of ECU communication required a series of complex, interconnected analogue wiring to facilitate the necessary information between each unit:

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Naturally, with more wiring came more problems. Errors and failures were more frequent, the weight of the system was increased, and the costs for integrating all these wires were high.

When the CAN Bus system entered the scene, it brought the opportunity for refreshing simplicity and reliability. The CAN Bus enables each ECU to communicate with the entire system via a single line instead of the overly complicated system of direct wiring.

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CAN Bus systems are ubiquitous in vehicles and machinery for four good reasons:


1. Low cost and simple 

As previously mentioned, CAN enables ECUs to communicate via a single line rather than via a series of complex, direct cabling. This results in fewer errors, a reduction in weight and lower wiring costs.

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2.    Centralised communication

The single communication line connecting the ECU to its sensors and controls makes all diagnostical data accessible from a central point. It also facilitates data logging and configuration, meaning a user can save a history of all messages being broadcast on the system for debugging purpose and give the user the ability to adjust the sensors and controls.

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3.    Reliable

The system is resilient against electrical anomalies and electromagnetic interference – making it ideal for safety-critical applications.

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4.   Efficient

CAN Bus messages are prioritised, so that critical data receives immediate bus access, without interfering with other CAN Bus messages.

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As you can see, CAN Bus systems have a bag full of advantages that can improve the efficiency of your machinery.

Thank you so much for reading!

If you have further questions relating to CAN Bus or any other tech topic, feel free to reach out to the SAPHI team here.

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