CAN XL – Extension of CAN Technology for data-intensive Communication Systems

CAN XL significantly broadens the application range of CAN technology beyond CAN CC and CAN FD. The decisive factor is not only the increased payload size, but also the combination of large payloads, separated arbitration and data phases, and a substantially higher effective data throughput.

CAN CC is limited to 8 bytes of payload with bit rates up to 1 Mbit/s, making it particularly well suited for small, time-critical control messages. CAN FD increases the payload to 64 bytes and typically supports data phase bit rates between 2 and 8 Mbit/s. This enables the transmission of moderate data volumes. However, protocol overhead still dominates when transferring larger data objects.

CAN XL fundamentally changes this relationship. With payloads of up to 2048 bytes, large data blocks can be transmitted in only a few frames. Arbitration intentionally remains at classic CAN bit rates of up to 1 Mbit/s, preserving deterministic bus behavior. Once arbitration is complete, data transmission proceeds at significantly higher bit rates. Practical implementations operate from several Mbit/s up to double-digit Mbit/s speeds, typically between 5 and 16 Mbit/s.

The key advantage is that effective payload efficiency increases substantially as payload size grows. As a result, CAN XL is particularly well suited for data-intensive communication while maintaining the proven strengths of CAN, such as deterministic arbitration and robust error handling. In this way, CAN XL bridges the gap between traditional CAN communication and Ethernet-based solutions.

CAN XL is primarily driven by requirements from the automotive industry. The shift from domain-based to zonal vehicle architectures, along with the growing proportion of software in modern vehicles, demands scalable communication networks that provide higher data throughput and a clearly structured protocol design.

Within these architectures, CAN CC and CAN FD increasingly reach their functional limits – particularly when intended to serve as a backbone connecting zones or ECUs. However, the technical principles behind CAN XL are not confined to automotive applications. Industrial systems are also experiencing rising communication demands due to larger data volumes, distributed intelligence, and the parallel use of multiple protocols.

CAN XL enables the targeted expansion of existing network architectures in scenarios where Ethernet may offer high performance but is not always the optimal architectural or economic choice. One of the key advantages of CAN XL is its ability to combine high data transmission capacity with deterministic bus behavior. Time-critical communication via CAN CC or CAN FD can coexist with data-intensive CAN XL transmissions within a shared network environment. This allows existing infrastructures to remain in operation and be incrementally enhanced with CAN XL – without abandoning established and proven communication concepts.

For esd electronics, CAN XL represents a natural continuation of a technology and product portfolio that has been successfully established over many years. For more than 35 years, esd has developed hardware and software solutions for CAN CC, CAN FD, and related communication architectures, supporting customers in the design, implementation, and long-term operation of CAN-based systems.

This extensive experience has given esd electronics a deep understanding of the CAN data link layer, its protocol mechanisms, and the specific requirements of industrial applications. 

The company’s focus remains on long-term reliability, technical consistency, and seamless integration into existing system environments.
Within this context, CAN XL is regarded as a complementary enhancement – one that extends established technologies without replacing proven concepts.