Schneider Electric IP67 manual About CANopen, Protocol, Physical Layer

CANopen Network Interface

About CANopen

Introduction	CANopen is a standard fieldbus protocol for industrial control systems. It is
	particularly well suited to real-time PLCs, as it provides an effective, low-cost
	solution for industrial applications.
The CANopen
	The CANopen protocol was created as a subset of CAL (CAN Application Layer). By
Protocol	defining profiles, it is able to be even more specifically adapted to use with standard
	industrial components. CANopen is a CiA standard (CAN in Automation) that was
	very quickly adopted by users when it was put on the market. In Europe, CANopen
	is now recognized as the industry standard for industrial systems based on a CAN
	design.
Physical Layer
	CAN uses a differentially driven two-wire bus line (common return). A CAN signal is
	the difference between the voltage levels of the CAN_H and CAN_L wires. (See
	figure below.)
	The following diagram shows the components of the physical layer of a two-wire
	CAN bus:

	5		5		5
4		1
				3
		2

1CAN_H wire

2CAN_L wire

3Potential difference between CAN-H/CAN-L signals

4Line terminator 120 Ω

5Connected devices,

4

The bus wires can be routed in parallel, twisted or shielded form in accordance with electromagnetic compatibility requirements.

1606218 02 08/2006 49