Chapter 2 Decentral block periphery CAN-Bus CANopen
Manual VIPA System 100V
2-2
HB100E - SM-CAN - Rev. 15/02
Principles of CANopen
All the modules in this chapter have got the UL Certification:
The CAN-Bus (
C
ontrol
A
rea
N
etwork) is an international open fieldbus
standard for building, manufacturing and process automation and has been
developed for automotive production.
Due to the wide range of error localization possibilities, the CAN-Bus is
seen as the bus system with the highest security with a rest error
probability of less than 4.7 x 10
-11
. Defective messages are signalized and
automatically transferred again.
In contrast to PROFIBUS and Interbus, CAN-Bus also defines several 7-
layer user profiles under the CAL-Layer-7-protocol (CAL=CAN application
layer).
One of those user profiles is CANopen, which standardization is controlled
by the CiA CAN in Automation e.V.
CANopen is the user profile for industrial real-time systems and is at this
time on its way through the manufacturing sites. CANopen has been
published as Profile DS-301 from the CAN-User Organization (C.i.A). The
communication profile DS-301 serves the standardization of the devices to
ensure the compatibility of the products from different manufacturers.
Another step is the device profile DS-401 that standardizes the device
specific and the process data of the digital and analog in-/output modules.
CANopen consists of the communication profile that defines the objects
used for the transfer of certain data, and the device profiles that define the
kind of data transferred with the objects.
The CANopen communication profile bases on an object directory
comparable to the PROFIBUS directory. The communication profile DS-301
defines two kinds of objects and some special objects:
•
Process data objects (PDO)
PDOs provide the transfer of real-time data
•
Service data objects (SDO)
SDOs allow the read and write access to the object directory
UL Certification
General
CANopen
PDO and SDO
UL-Recognition-Mark
Underwriters Laboratories (UL)
Standard UL 508, File Nr.: E234291