What is Data Link Layer? Many of the systems we build today, from complex vehicle safety to automated manufacturing, require the steady flow of data between multiple devices. Network communication seems simple, but to understand why it works so well, we need to look at how data moves around the system. Accuracy of that data is essential, and central to providing that accurate communication is OSI layer 2, also known as the data link layer. It oversees all data as it moves between the physical and network layers, checking for errors and fixing problems as it does. Defining the OSI Model The OSI model is the framework we use to define how network communications function. It defines the seven layers of the process, to ensure accurate, fast and efficient communications between all devices on your network. Here, we'll take a look at the data link layer. What does the OSI Data Link Layer Do? While the data link layer carries out a number of functions, it’s main function is to ensure that data transfer is reliable and accurate, spotting and correcting data errors as it is moved from the physical layer. Using a number of technologies, including framing, error and flow control, the data link layer ensures data accuracy, allowing network based systems to perform reliably. Data Link Layer in Use Well known protocols such as CAN Bus and CANopen, widely used in the automotive and manufacturing industries, show just how effective the data link layer can be. Can Bus — Commonly used in the automotive industry, and a frequent platform for industrial automation, the Controller Area Network Bus, or CAN Bus protocol provides a defined set of rules for data framing, error detection and signaling for data flows across the data link layer. In the automotive world, it is used to enable the essential low-latency, accurate communications between the ECU and other devices within a vehicle. CANopen — Built onto the CAN Bus, this is an application layer protocol that utilizes the capabilities of the data link layer to enable real-time control applications, such as sensor data exchanges, device configuration and network management. Conclusion By providing continual error checking and other tools, the data link layer delivers the robust, accurate communications that we need in todays integrated systems. Delivering seamless accuracy checks, the data link layer means we can trust that these complex systems will continue to deliver the performance and capabilities that are required.