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Baumer_GIM500R_CANopen_MA_EN.docx
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03.19
3.3.3
Service data communication
The service data objects correspond to the standards of the CiA. It is possible to access an object via index
and subindex. The data can be requested or where applicable written into the object.
General information on the SDO
Structure of an
SDO telegram
:
COB ID
DLC
Command
Object L Object H Subindex Data 0 Data 1 Data 2 Data 3
An SDO-
COB ID
is composed as follows:
Master -> Sensor
: 600h + Node ID
Sensor -> Master
: 580h + Node ID
DLC
(data length code) describes the length of the telegram. This is composed as follows:
1 byte c 2 bytes 1 byte su no. of data bytes (0 - 4).
The
command byte
defines whether data is read or set, and how many data bytes are involved.
SDO command
Description
Data length
22h
Download request
Max. 4 Byte
Transmits parameter to sensor
23h
Download request
4 byte
2Bh
Download request
2 byte
2Fh
Download request
1 byte
60h
Download response
-
Confirms receipt to master
40h
Upload request
-
Requests parameter from sensor
42h
Upload response
Max. 4 byte
Parameter to master with max. 4 byte
43h
Upload response
4 byte
4Bh
Upload response
2 byte
4Fh
Upload response
1 byte
80h
Abort message
-
Sensor signals error code to master
An
abort message
indicates an error in the CAN communication. The SDO command byte is 80h. The
object and subindex are those of the requested object. The error code is contained in bytes 5…8.
ID
DLC
Byte 1 Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
580h + Node ID 8
80h
Object L Object H Subindex ErrByte 0 ErrByte 1 ErrByte 2 ErrByte 3