Technical Manual N5 (CANopen)
8 CANopen
•
3 byte data length:
27
h
•
4 byte data length:
23
h
The
<Data>
field is written with the data that are to be written; the LSB of the data is entered in byte 4.
The answer from the server is either a confirmation of the write operation or an error message
(structure of the messages: see following figure). In the latter case, the reason for the error is also sent
with the data (see list of the SDO error messages in section SDO error messages).
0x00
CAN ID
Data
Byte 1
Byte 2
580+NodeID
0x60
<IDX>
Byte 3
Byte 4
<SUBIDX>
Byte 5
Byte 6
Byte 7
Byte 0
0x00
Init SDO Download confirm (OK)
0x00
0x00
0x00
0x00
CAN ID
Data
Byte 1
Byte 2
580+NodeID
0x80
<IDX>
Byte 3
Byte 4
<SUBIDX>
Byte 5
Byte 6
Byte 7
Byte 0
<ERROR CODE>
Init SDO Download confirm (error)
Client
Server
Example: Set object 607A
h
:00
h
(target position, SIGNED32) to value
3E8
h
(=1000
d
) of a controller with
node-ID 3:
603 | 23 7A 60 00 E8 03 00 00
Where
•
Byte 1 (
23
h
): SDO expedited download, 4 bytes of data (SIGNED32)
•
Bytes 2 and 3 (
7A
h
60
h
): index of object is
607A
h
•
Byte 4 (
00
h
): subindex of object is
00
h
•
Bytes 5 to 8 (
E8
h
03
h
00
h
00
h
): value of object:
000003E8
h
If successful, the controller responds with this message:
583 | 60 7A 60 00 00 00 00 00
SDO upload
A CAN message for reading an object from the object dictionary has the following structure:
CAN ID
Data
Byte 1
Byte 2
600+NodeID
0x40
<IDX>
Byte 3
Byte 4
<SUBIDX>
Byte 5
Byte 6
Byte 7
Byte 0
0x00
Init SDO Upload request
Client
Server
0x00
0x00
0x00
The server responds with one of the following messages.
Version: 2.0.1 / FIR-v1650
108
