Danfoss CAN Controller User guide

CAN

Controller

Area

Network

Technical

Information

		174
		155
		POWER
		SYSTEM
	55,75	60,25
	8,5	8,5
		10
	9
	10

123,5

10,5

AMP Stecker

AMP Connector

1	14
15	28

29

42

55

	CAN Controller Area Network
	Technical Information
	Overview
HISTORY	Forced by the increasing number of distributed control systems in cars and the
	increasing wiring costs of electronics, the availability of a powerful and reliable data
	communication system for the exchange of information between the different control
	units was becoming urgent.
	This was the starting point for BOSCH, a main provider of electronic car equipment to
	develop the CAN protocol and standardize it as an international standard in ISO 11898.
	1989 the first protocol controller chip was provided by INTEL.
WHAT IS CAN	CAN is a serial bus system which is especially suited for connecting devices within a
	system or sub-system.These devices (nodes) can be intelligent devices as well as sensors
	and actuators.
	CAN is a serial bus system with multi-master capabilities, that means that all CAN
	nodes are able to transmit data and several CAN nodes can request access to the bus
	simultaneously. A transmitter sends a message to all CAN nodes (broadcasting).
	A CAN message can transmit from 0 up to 8 bytes of user information. Each CAN Message
	starts with a so called identifier followed by the data bytes.This identifier can be 11
	Bit or 29 Bit wide. If the identifier is 11 bit wide, than it is a message in„standard
	format“ (CAN specification 2.0 Part A). Otherwise it is a message in the„extended format“
	(CAN specification 2.0 Part B). Please be aware that not all CAN controller supports the
	extended format.
	Each node decides on the basis of the identifier received whether it should process the
	message or not.The identifier also determines the priority that the message have in
	competition for bus access.
	One of the outstanding features of the CAN bus is its high transmission reliability.The
	CAN protocol controller detects a stations error and evaluates it statistically in order to
	take appropriate actions.These may extend to disconnecting the CAN node producing
	the errors.
BENEFITS	The use of a CAN system increases the flexibility of a system. One of the most obvious
	benefits is reduced wiring. A single two-wire bus is all that is needed to connect several
	CAN devices.This reduces costs, simplifies mechanical design, and makes it easier to
	insert additional devices into a system.
	The key benefit of CAN, like any network, is that it makes it possible to share resources
	and information between devices. This means that one sensor can easily be shared
	between two or more controllers, or two controllers may share information about their
	respective subsystems. Instead of using point to point communications, any device on a
	CAN network can communicate with any other.
	An additional benefit of this is that system diagnostics can be centralized and simplified.
	As a single device can access all of the devices on the CAN, it is possible to centralize
	diagnostic tools to a single access point.
	© 2001, Sauer-Danfoss
	Sauer-Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Sauer -Danfoss reserves the
	right to alter its products without prior notice.This also applies to products already ordered provided that such alterations can be made without
	subsequent changes being necessary in specifications already agreed. All trademarks in this material are properties of the respective companies.
	Sauer-Danfoss and the Sauer-Danfoss logotype are trademarks of the Sauer-Danfoss Group. All rights reserved.
2	BLN-96-9916-E • Rev. A • 08/2001