Controller area networks (CAN) are serial communication buses designed for use in harsh environments.
A CAN bus is a multi-master message-based protocol where all CAN devices share equal opportunities to start communication with each other.
CAN buses find applications in the electronic networking used in vehicles.
CAN serial communication is popular in automotive applications
Controller area network (CAN) serial communication is popular in automotive applications, as it offers low-level networking solutions for onboard communication in vehicles. Controller area networks allow electronic control units in vehicles to communicate over a single pair of wires. These networks are employed for communication between the central locking system, gear shift control, engine management system, lighting control, ABS, air conditioner, and various other systems in automobiles.
CAN Serial Communication
Controller area networks (CAN) are serial communication buses designed for use in harsh environments. They offer flexible and robust performance with reduced cable wiring. With a single pair of wires, CAN serial communication can establish networking within high-speed vehicles or in any real-time system. The standard CAN serial communication data transfer rate reaches up to 1Mbps and provides outstanding error detection and correction capabilities. The multi-drop bus protocol of a CAN bus supports multiple communication nodes and is best suited for distributed systems. In distributed systems, the CAN bus offers a communication protocol for exchanging data between connected devices and microcontrollers.
CAN Bus Protocol
CAN bus protocol links electronic subsystems in vehicles or in industrial systems and allows their interaction in a network. The CAN bus is a bidirectional serial communication protocol that uses a two-wire system to connect different devices. This multi-master message-based protocol ensures all CAN devices share equal opportunities to start communication with each other.
CAN bus protocol can be described by the following points:
- CAN bus protocol utilizes differential signaling over twisted pair wires.
- There is no addressing system in CAN bus serial communication; it is based on a prioritized message system.
- Access to the CAN bus is controlled using non-destructive bit-wise arbitration.
- CAN bus messages are at least 8 data bits protected by a checksum.
- When a message is not received properly, the error handling scheme in the CAN bus communication protocol resends the message.
- CAN bus protocols are good at isolating faults as well as removing faulty nodes from the bus.
CAN Bus Versions
- CAN 2.0 A - The low-speed version, also known as standard or basic CAN. This CAN version, defined by the ISO11519 standard, uses an 11-bit message identifier.
- CAN 2.0 B - CAN 2.0 B is the high-speed version, referred to as full CAN or extended-frame CAN. This version is defined by the ISO11898 standard and uses a 29-bit message identifier.
- CAN FD - This is the CAN protocol that uses a flexible data rate, where the data rate can go up to 15 Mbps and a bus length around 10 meters.
CAN Bus Advantages
- CAN buses offer a durable and inexpensive communication network that doesn’t require separate analog and digital inputs to connected devices. The capability of a single CAN interface reduces the cost and weight of communication buses in vehicles.
- Priority-based message transmission supports the uninterrupted sharing of high-priority messages and allows the CAN bus protocol to meet deterministic timing constraints.
- The structure of a CAN bus is such that it allows modifications in the network with minimal impact.
- Upon detection of errors, nodes are either prevented from sending errors or completely disconnected from the network.
CAN Bus Applications
CAN buses are used in the electronic networking used in vehicles as well as other industries. In railways, CAN bus protocol is used for linking door units, passenger counting units, and brake controllers. The CAN bus assists the communication of navigation systems, cockpit PCs, and flight-state sensors in aircraft as well. An embedded network of medical devices can be managed using CAN serial communication. Non-industrial applications of CAN serial communication include coffee machines, automatic doors, sports cameras, telescopes, and laboratory equipment.
CAN bus serial communication is the core of in-vehicle communication systems as well as industrial communication networks. This low-cost, lightweight communication protocol is suitable for high-level networking applications.
Cadence software can help you design CAN bus architecture for automotive and industrial systems. Cadence offers a set of powerful PCB design features and simulation tools that help build communication systems.
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