Welcome to

Everything about the CAN bus or Controller Area Network


This Page is dedicated to North American Users and Developers of Controller Area Network applications
Also see www.CANopen.us - everything about the higher-layer CAN protocol CANopen

NOTE: This is not the CiA.
The official, international CAN pages are maintained by the CiA (CAN in Automation users and manufacturers group)

Visit CANopenStore US or CANopenStore EU

Upcoming ESAcademy Classes

CAN (also referred to as CANbus or CAN bus) is a network used in many every-day products consisting of multiple microcontrollers that need to communicate with each other. CAN is implemented in hardware in microcontrollers of about 25 chip manufacturers. If you don't know much about the CAN bus, here is a historic summary of almost 25 years of CAN.

The original CAN specification from Robert Bosch is available here: CAN Spec

CAN provides a safe communication channel to exchange up to 8 bytes between several network nodes. Additional network functionality like which node talks to which others,  when to trigger transmit messages, how to transmit data longer than 8 byte - all of these functions are specified in so-called higher-layer protocols (in network terms, CAN is a layer 2 implementation - higher layers are implemented in software). Some of the more popular higher-layer CAN bus protocols are CANopen, DeviceNet and J1939.

The lastet add-on to the specification is called CAN-FD where FD stands for Flexible Datarate. In CAN-FD version the data size is increased of up to 64 bytes and the bitrate in the data field can be multiplied. First implementations and products are available. The specification is here: CAN-FD Spec

A list of Frequently Asked Questions also covering CAN issues are available on CANopen.us.

Usually a high-layer CAN protocol is used "on top" of CAN to provide extended functionality, such as node detection and management, various communication services. One of the popular protocols is CANopen. The educational version of the program CANopen Magic from ESAcademy is a CANopen monitor, analyzer and simulator. It can be downloaded for free and can be used to simulate multiple CANopen devices.

External CAN bus links listed on this page:

CAN Books available in English

Controller Area Network
by Konrad Etschberger, 2001
Check reviews, pricing and availability: amazon.com

CAN System Engineering: From Theory to Practical Applications
by Wolfhard Lawrenz, 1997
Check reviews, pricing and availability: amazon.com

Embedded Networking with CAN and CANopen
by Olaf Pfeiffer, Andrew Ayre, Christian Keydel, 2003
Check reviews, pricing and availability: amazon.com

  • Reading & Learning
    • Selecting a CAN controller
      There are about 25 chip manufacturers producing microcontrollers with on-chip CAN interfaces. Many differ substantially from each other - what are the selection criteria we can go by?
    • Betting on CAN and CANopen
      An article giving answers to questions like: In which market segments are CAN and CANopen used today? How many CAN nodes are out there? In which market segments will CAN and CANopen be used in the future?


CANbus.us is maintained by
the Tutors of ESAcademy