Delta Electronics VFD-E manual SDO Service Data Object, Pdo Sdo, Emerg

Appendix E CANopen Function

	Initializing	Pre-Operational
PDO
SDO		○
SYNC		○
Time Stamp		○
EMERG		○
Boot-up	○
NMT		○

NMT Protocol is shown as follows:

Operational

○

○

○

○

○

○

Stopped

○

NMT Master Request

request

Cs

Start Remote Node			NMT Slave(s)
	byte 0	byte 1	Indication(s)
	CS	Node-ID		Indication
	COB-ID=0				Indication
					Indication

Value	Definition
1	Start
2	Stop
128	Enter Pre-Operational
129	Reset Node
130	Reset Communication

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 Revision June 2008, 04EE, SW--PW V1.11/CTL V2.11