MadgeTech Blog

The Science Behind CAN Bus and Why It’s Important to Monitor

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A vehicle’s Controller Area Network System, or CAN, is the system that connects all of the essential Electrical Control Units, or ECUs. At its core, it is a centralized network of communications that allows the vehicle to operate and function. It does this by providing each individual system with the ability to communicate with one another.

While the overall system of the CAN bus is rather complex, its purpose and operation are basic. The CAN acts as a centralized hub which allows all of the vehicle’s various ECUs to communicate without requiring the point-to-point wiring. There are many benefits of having the CAN, which is why all major manufacturers have used the system for several decades.

The CAN provides the vehicle’s systems a main location for data collection, making engine, road, and diagnostic testing simple and easy. It also has the ability to prioritize data signals by importance as the CAN receives many SPNs, or suspect parameter numbers, at once.

Suspect Parameter Number

An SPN is a number assigned by the Society of Automotive Engineers (SAE) to a specific parameter within a parameter group. This number is used to describe a physical value, a status, or command. When a vehicle is running, the CAN is receiving these messages that are critical to performance and maintenance by triggering the lights on the dashboard or error messages if potential issues are detected. 

However, the data relayed to the CAN system is not legible to humans. This is where CAN Bus monitoring comes into play, decoding and translating the data into an easy-to-read format that is widely recognized as SAE J1939 compliant CAN messages.

CAN Bus Monitoring

Real-time data logging, whether it be engine or road testing, can provide users the ability to view data immediately. Features such as threshold alerts notify users of any abnormalities in the system or irregularities in driving patterns that could damage the engine or vehicle. This data can be offloaded and exported to a computer for detailed analysis and recordkeeping.

There are many benefits to logging CAN Bus communications. SPN data allows users to focus on optimizing vehicle performance through minor adjustments, and because the CAN is linked to all ECUs units, updates can be made without requiring external hardware. This data can also alert users to fault statuses that can lead to expensive damages or downtime.


MadgeTech makes it easy to monitor, record and view CAN messages in real-time. The Titan S8-CAN is a data acquisition system that can display as many as 23 SPN simultaneously. Designed for use with Tier 1 through Tier 4 diesel engines and diesel fleets, the Titan S8-CAN easily connects to the CAN via its diagnostic port for immediate use.

To learn more about the SAE J1939 compliant Titan S8-CAN, call us at (603) 456-2011 or email [email protected].

About MadgeTech Marketing:

Found in 1996, MadgeTech takes pride in maintaining our production process entirely out of our headquarters in Warner, New Hampshire. Proudly known as an industry expert, MadgeTech data logging solutions are sold in more than 100 countries around the world to the world’s most regulated industries, providing the validation needed for compliance and quality control.