Delta ASDA-A3 Series, User Manual, Page: 669 / 845

CANopen Mode ASDA-A3
12-8
12
12.2.2.2 Service data object (SDO)
With Service data objects (SDOs), you can write or read objects. The SDO message format is
mainly composed of COB-ID and SDO data. SDO data can transmit up to 4 bytes.
Controller
Servo drive
COB-ID
600h+
Node-ID
Packet (8 bytes in total)
0 1 2
3
4 5 6 7
Byte Function
Byte 0 Command code
Byte 1 - Byte 2 Object index
Byte 3 Object sub-index
Byte 4 - Byte 7 Data
 Write data with SDO
To use an SDO to write data with the controller, you need to write the request code, index, and
data according to the SDO format. The servo drive then returns the corresponding message
based on the written data.
The following figure shows the packet format when the controller sends the SDO for writing data:
Controller Servo drive
COB-ID
600h+
Node-ID
Packet (8 bytes in total)
0 1 2
3 4
5 6 7
Function
code
Object index
Object
sub-index
Data
Description
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
23h - - - Data
Write 4 bytes of
data.
2Bh - - - Data
Write 2 bytes of
data.
2Fh - - - Data
Write 1 byte of
data.