Introduction to CAN (Control Area Network)
Originally developed by Robert Bosch for automobile in vehicle network Multi-drop,Multi-master serial bus provides communication between controllers,sensors and actuators Very reliable and robust,well proven technology Inexpensive
Standards
CAN 2.0 A -Standard format
CAN 2.0 B -Extended format
International Standard ISO 11898 -ISO 11898-2 high speed applications up to 1 mbps -ISO 11898-3 Low speed applications up to 125 Kbps
Applications of CAN
Automotive Military Vehicle Industrial Machinery Medical Systems Agricultural Machinery Marine control and navigation Elevator Control Systems
CAN Characteristics
All messages are broadcast Any node is allowed to broadcast message Each message contains an ID that identifies the source or content of a message Each receive decided to process or ignore each device
Network Size
The maximum number of nodes is not specified Networks are limited by electrical loading,up to 64 nodes is normal
Four Message Types
1.Data Frame -Used to transmit data
2.Remote Frame -Used to request data transmission
3.Error Frame -Sent by a node that detects an error
4.Overload Frame -Sent by a node to request a delay transmission
Error Detection Capabilities
Bit error Acknowledge error Form error CRC error Stuff error
