E.1.4.2 Sdo (Service Data Object) - Delta Electronics AC Motor Drive VFD-E User Manual

Appendix E CANopen Function |
PDO
SDO
SYNC
Time Stamp
EMERG
Boot-up
NMT
NMT Protocol is shown as follows:
NMT Master
Request
request
Cs
Value
1
2
128
129
130

E.1.4.2 SDO (Service Data Object)

SDO is used to access the Object Dictionary in every CANopen node by Client/Server model.
One SDO has two COB-ID (request SDO and response SDO) to upload or download data
between two nodes. No data limit for SDOs to transfer data. But it needs to transfer by
segment when data exceeds 4 bytes with an end signal in the last segment.
The Object Dictionary (OD) is a group of objects in CANopen node. Every node has an OD
in the system, and OD contains all parameters describing the device and its network
behavior. The access path of OD is the index and sub-index, each object has a unique index
in OD, and has sub-index if necessary.
The request and response frame structure of SDO communication is shown as follows:
E-6
Initializing
○
Start Remote Node
byte 0
CS
COB-ID=0
Definition
Start
Stop
Enter Pre-Operational
Reset Node
Reset Communication
Pre-Operational
○
○
○
○
○
byte 1
Node-ID
Revision June 2008, 04EE, SW--PW V1.11/CTL V2.11
Operational Stopped
○
○
○
○
○
○
NMT Slave(s)
Indication(s)
Indication
Indication
Indication
○