Справочник Пользователя для National Instruments NI-DNET

Скачать
Страница из 86
© National Instruments Corporation
A-1
A
DeviceNet Overview
This appendix gives an overview of DeviceNet.
History of DeviceNet
The Controller Area Network (CAN) was developed in the early 1980s by 
Bosch, a leading automotive equipment supplier. CAN was developed to 
overcome the limitations of conventional automotive wiring harnesses. 
CAN connects devices such as engine controllers, anti-lock brake 
controllers, and various sensors and actuators on a common serial bus. 
By using a common pair of signal wires, any device on a CAN network can 
communicate with any other device.
As CAN implementations became widespread throughout the automotive 
industry, CAN was standardized internationally as ISO 11898, and major 
semiconductor manufacturers such as Intel, Motorola, and Philips began 
producing CAN chips. With these developments, many manufacturers of 
industrial automation equipment began to consider other applications of 
CAN technology. Automotive and industrial device networks showed 
many similarities, including the transition away from dedicated signal 
lines, low cost, resistance to harsh environments, and excellent real-time 
capabilities.
In response to these similarities, Allen-Bradley developed DeviceNet, an 
industrial networking protocol based on CAN. DeviceNet built on CAN’s 
communication facilities to provide higher-level features which allow 
industrial devices from different vendors to operate on the same network.
Soon after DeviceNet was developed, Allen-Bradley transferred the 
specification to an independent organization called the Open DeviceNet 
Vendor’s Association (ODVA). ODVA formally manages the DeviceNet 
Specification
 and provides services to facilitate development of DeviceNet 
devices and tools by various vendors. Due in large part to the efforts of 
ODVA, hundreds of different vendors now provide DeviceNet products for 
a wide range of applications.