Instruction Manual
SBI-COP/DN-AGy Card •
Eng
lish
Chapter 3 - Integrated CANopen Interface
CANopen is a communication profile for CAL-based industrial systems. The
reference document is the CANopen CAL-Base COMMUNICATION PROFILE
for Industrial Systems; CiA Draft Standard 301 Version 3.0. Issue October
1996 by CAN in Automation e. V.
The CAN protocol (ISO 11898) is CAN2.0A with an 11-bit identifier.
The integrated CANopen interface is developed as a “Minimum Capabilty
Device”.
The data exchange is cyclic; the Master unit reads the Slave input data and
writes the Slave output data; the Baud Rates for the interface are those
foreseen by the CANopen specification.
The physical support is given bu the standard CANopen; the maximum
number of Slaves connected to the Bus is 127.
3.1 CANopen Functions
This chapter describes the controlled functions of the CANopen communica-
tion profile. The main features are:
1) The “Minimum Boot-up” is managed; the “Extended Boot-up (CAL)” is
not managed.
2) The SYNC function is implemented.
3) The PDO asynchronous assignment and RTR are managed.
4) The Node Guarding is managed.
5) The emergency message is managed (“EMERGENCY”).
6) The Dynamic ID distribution function (DBT slave) is not managed.
7) A “Pre-Defined Master/Slave connection” is implemented to simplify the
Master tasks during the initialization phase. “Inhibit-Times” (in units of
100 uS) can be modified up to a value of 1 min.
8) The high-resolution synchronization is not supported.
9) “TIME STAMP” is not managed.
10) On the access of the structured parameters, the OFFhex option subindex
(access to the whole object) is not managed.
11) In order to obtain a higher efficiency level, only the “Expedited” data
transfer (max. 4 Bytes) of the SDO services is managed.
3.1.1 Pre-defined Master/Slave Connection
The “Pre-defined Master/Slave connection” allows a peer-to-peer com
-
munication between one Master and 127 Slaves according to a predefined
array of communication objects. The devices are identified by their address
(Node-ID) located in the 7 less significant bits of the message identification
(COB-ID), with the exception of the objects addressed to the whole network
(broadcast), whose address is zero. The 4 remaining most significant bits
(function code) differentiate each single communication object.
3.1.2 NMT Services (Network Management)
The NMT “mandatory” services are:
- Enter_Pre-Operational_State
CS = 128
- Reset_Node
CS = 129
CiA : CAN in Automation, user
international group.
CAN : Controller Area Net-
work.
NMT: Network Management.
It is a service element of the
CAN Application Layer in
the CAN Reference Model;
it initializes, configures and
controls the errors of a CAN
network.
PDO: Process Data Object,
service messages without
confirmation used for the
real time data transfer from/to
the device.
DBT: Distributor. It is a service
element of the CAN Applica-
tion Layer in the CAN Refer-
ence Model; the DBT has the
task to assign COB-ID to the
COBs used by the CMS.
SDO: Service Data Object,
service messages with con-
firmation used for the acy-
clic data transfer from/to the
device.
