3 the canopen protocol, The canopen protocol – NORD Drivesystems BU0060 User Manual

Page 56

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CANopen – Supplementary manual options for NORD - Frequency Inverters

56

BU 0060 GB-4112

4.3 The CANopen protocol

Object Index (OI)

The OI contains all objects of the device. Objects depict the visible functionality. They
contain data, parameters or functions. Access is gained via SDOs. An object is
addressed via the Index (16 Bit) and the SubIndex (8Bit). The OI is divided into the
following areas:
0000h...1FFFh: Communication specific objects
2000h...5FFFh: Manufacturer-specific objects
6000h...9FFFh: Standardised device profile objects
A000h...FFFFh: Reserved

Service data obj.
(SDO)

SDOs are used for confirmed transfer of data of any length between two network
subscribers: The SDO client is the initiating subscriber and has direct access to the OI
inputs of the SDO server (read and write). The SDO transfer is normally used for
parameterisation and service purposes.

Process data obj.
(PDO)

PDOs are used for transferring process data. The process data can contain a maximum
of 8 bytes. Transfer is made without confirmation. The significance of the data
transferred is determined by the identifier and the set PDO mapping. A PDO always has
a producer (transmitter). Several consumers (receivers) may exist.

PDO mapping

In objects 1600h-1603h / 1A00h..1A03h it is possible to set which objects
(setpoint/actual values) are transferred into the PDO telegrams.

Identifier

Every CAN message has an 11 bit identifier. This identifier is used for addressing and
priority assignment.
CANopen defines a preset identifier assignment which facilitates communication
between a higher level device and up to 127 other devices. The 11 bit identifier is
broken down as follows:

10

8

8

7

6

5

4

3

2

1

0

Function code

Node identifiers (1-127)

Object

Function code

Resulting COB-ID

OI entry

NMT

0000

0

SYNC

0001

80h

1005h-1007h

Time stamp

0010

100h

1012h, 1013h

Emergency

0001

81h – FFh

1014h, 1015h

PDO1 (Tx)

0011

181h – 1FFh

1800h, 1A00h

PDO1 (Rx)

0100

201h – 27Fh

1400h, 1600h

PDO2 (Tx)

0101

281h – 2FFh

1801h, 1A01h

PDO2 (Rx)

0110

301h – 37Fh

1401h, 1601h

PDO3 (Tx)

0111

381h – 3FFh

1802h, 1A02h

PDO3 (Rx)

1000

401h – 47Fh

1403h, 1602h

PDO4 (Tx)

1001

481h – 4FFh

1803h, 1A03h

PDO4 (Rx)

1010

501h – 57Fh

1403h, 1603h

SDO (Tx)

1011

581h – 5FFh

1200h

SDO (Rx)

1100

601h – 67Fh

1200h

NMT Error Control

1110

701h – 77Fh

1016h, 1017h


Pos : 86 /Anl eitungen/ Elektroni k/ Bus s yst eme/4. Kommuni kati on und Prot okoll + Proz ess datentr ans fer /CAN open [ BU 0060]/D as C ANopen Pr ot okoll/N et z wer k M anag ement (NMT) [CAN open] @ 1\ mod_1342093966683_388. doc x @ 32048 @ 3 @ 1

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