Controller Area Network

Controller Area Network
Original: unknown Vector: Pduive23 · Public domain · source
Name	Controller Area Network
Acronym	CAN
Developer	Robert Bosch GmbH
Introduced	1986
Standard	ISO 11898
Use	Automotive, Industrial Automation, Aerospace, Medical Devices

Controller Area Network Controller Area Network is a serial communication bus originally developed by Robert Bosch GmbH for robust microcontroller interconnection in automobiles. It revolutionized in-vehicle networking alongside developments from Bosch Ceres, progressed through standardization with International Organization for Standardization, and influenced protocols adopted by Toyota Motor Corporation, Volkswagen Group, and General Motors. CAN's impact echoes across implementations by Bosch Rexroth, Siemens AG, Honeywell International Inc., and research at Massachusetts Institute of Technology, enabling distributed control in systems studied at Stanford University, Imperial College London, and Technical University of Munich.

History

CAN was conceived in the early 1980s at Robert Bosch GmbH as an alternative to point-to-point wiring used in vehicles by companies like Mercedes-Benz and BMW. Researchers from institutions including University of Paderborn and collaborators with Daimler AG contributed to initial prototypes that were refined alongside standards efforts at International Organization for Standardization and incorporated into product lines of Bosch Automotive Electronics. Early commercial deployment involved suppliers such as Continental AG, Magneti Marelli, and Delphi Automotive; subsequent diffusion saw adoption by Fiat Chrysler Automobiles, Renault–Nissan, and Ford Motor Company. The ISO 11898 series codified CAN features while academic analyses from ETH Zurich and University of Michigan explored fault tolerance, leading to variants like CAN FD and research collaborations with NASA and European Space Agency for aerospace and satellite applications.

Architecture and Protocol

CAN employs a multi-master, message-based protocol developed by engineers at Robert Bosch GmbH with arbitration and nondestructive bus access mechanisms inspired by earlier work at Motorola and Intel Corporation. Logical design separates the data link and physical layers, aligned with guidance from International Organization for Standardization and engineering practices taught at Massachusetts Institute of Technology and Caltech. Arbitration uses identifier priority; prioritization schemes informed by scheduling research at Carnegie Mellon University and University of California, Berkeley. Error-detection mechanisms (CRC, ACK, bit stuffing) were refined through collaborations involving Fraunhofer Society and standards groups like International Electrotechnical Commission. Protocol enhancements such as Flexible Data-rate (CAN FD) were driven by stakeholders including Robert Bosch GmbH, NXP Semiconductors, Infineon Technologies, and Microchip Technology.

Physical Layer and Wiring

The CAN physical layer is specified in ISO 11898 and realized using transceivers from vendors like Texas Instruments, Analog Devices, Infineon Technologies, and NXP Semiconductors. Typical wiring employs twisted pair cable choices made by automotive suppliers such as Sumitomo Electric Industries and Yazaki Corporation, with termination resistors and common-mode chokes engineered by TE Connectivity and Hirose Electric Group. Connector standards and EMC mitigation reference practices from SAE International, Underwriters Laboratories, and regulatory testing at TÜV SÜD. Variants for industrial settings draw on cabling standards from International Electrotechnical Commission laboratories and fieldbus convergence with technologies used by ABB Group and Schneider Electric.

Frame Formats and Data Link Layer

CAN frame formats include base (11-bit) and extended (29-bit) identifiers; these design choices were discussed in technical forums including IEEE conferences and whitepapers from Bosch. The data link layer implements bitwise arbitration, CRC, acknowledgement, and error confinement models analyzed at Massachusetts Institute of Technology, ETH Zurich, and Delft University of Technology. Protocol timing and latency considerations were compared with solutions from Siemens AG and Rockwell Automation for real-time control in systems deployed by Siemens Mobility and Bombardier Transportation. Frame types (data, remote, error, overload) are applied in vehicle networks designed by Toyota Motor Corporation and in industrial controllers from Beckhoff Automation.

Higher-Layer Protocols and Applications

Higher-layer protocols built atop CAN include CANopen (CiA), DeviceNet (ODVA), SAE J1939, and ISO 15765 (UDS over CAN) used in diagnostics by Bosch, ZF Friedrichshafen AG, and Continental AG. CAN is used in vehicles by Ford Motor Company, Honda Motor Co., Ltd., Hyundai Motor Company, and in motorsport by teams at McLaren Racing and Scuderia Ferrari. Industrial automation uses CANopen in equipment from Siemens AG and Mitsubishi Electric Corporation, while building automation and medical devices reference standards developed by Philips, GE Healthcare, and Medtronic. Aerospace and defense programs at Lockheed Martin, Boeing, and Airbus have explored CAN and CAN FD for non-critical subsystems, with research collaboration at NASA Ames Research Center and European Space Agency.

Implementation and Tools

Microcontroller families with integrated CAN controllers include products from STMicroelectronics, NXP Semiconductors, Microchip Technology, and Renesas Electronics Corporation. Development environments and tools are provided by vendors such as Vector Informatik, Kvaser AB, PEAK-System Technik, IAR Systems, and Segger. Simulation and bus analysis use bus analyzers and oscilloscopes from Tektronix, Keysight Technologies, and software toolchains from MathWorks (Simulink) and National Instruments. Open-source stacks and projects hosted by communities around Linux Foundation initiatives, FreeRTOS integrations, and repositories from GitHub accelerate prototyping in academic labs at University of Cambridge and University of Tokyo.

Safety, Security, and Reliability

Functional safety practices for CAN deployments align with ISO 26262 guidance used by Volkswagen Group and Toyota Motor Corporation for automotive systems; fail-safe design patterns integrate redundancy and diagnostics studied at Daimler AG research centers. Security concerns (message spoofing, denial-of-service) prompted intrusion research from Klemens Tönnies-style academic teams and industry consortia including ENISA and initiatives at MITRE Corporation. Countermeasures involve gateways, message authentication, and anomaly detection employed by Bosch, Continental AG, and cybersecurity firms such as Trend Micro and Symantec Corporation. Reliability techniques like error confinement, fault-tolerant topologies, and formal verification are applied in products by ABB Group, Siemens AG, and validated in studies at ETH Zurich and Delft University of Technology.

Category:Computer buses