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National Instruments Corporation
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Introduction
This chapter gives an overview of CAN and the NI-CAN software.
CAN Overview
History and Usage of CAN
In the past few decades, the need for improvements in automotive
technology has led to increased usage of electronic control systems for
functions such as engine timing, anti-lock brake systems, and
distributorless ignition. With conventional wiring, data is exchanged in
these systems using dedicated signal lines. As the complexity and number
of devices has increased, usage of dedicated signal lines has become
increasingly difficult and expensive.
To overcome the limitations of conventional automotive wiring, Bosch
developed the Controller Area Network (CAN) in the mid-1980s. Using
CAN, devices (controllers, sensors, and actuators) are connected on a
common serial bus. This network of devices can be thought of as a scaled
down, real-time, low cost version of networks used to connect personal
computers. Any device on a CAN network can communicate with any other
device using a common pair of wires.
As CAN implementations increased in the automotive industry, CAN was
standardized internationally as ISO 11898, and CAN chips were created by
major semiconductor manufacturers such as Intel, Motorola, and Phillips.
With these developments, many manufacturers of industrial automation
equipment began to consider CAN for usage in industrial applications.
Comparison of the requirements for automotive and industrial device
networks showed many similarities, including the transition away from
dedicated signal lines, low cost, resistance to harsh environments, and high
real-time capabilities.
Because of these similarities, CAN became widely used in industrial
applications such as textile machinery, packaging machines, and
production line equipment such as photoelectric sensors and motion
controllers. By the mid-1990s, CAN was specified as the basis of many
