CANopen
• 85
Network Communication
WAGO-I/O-SYSTEM 750
CANopen
4.3.1.2.1 SDO Protocol
A specific protocol overhead that is indispensable for transmission and con-
tains the command specifier, the index and the sub-index of the entry to be
read/written.
4.3.1.2.1.1 General Design
Client
Client
Receive Service Data Object (RxSDO)
Transmit Service Data Object (TxSDO)
COB-ID = 1536 + Module ID
COB-ID = 1408 + Module ID
Data
Data
Sub
Index
Sub
Index
Index
High Byte
Index
High Byte
Index
Low Byte
Index
Low Byte
Command
specifier
Command
specifier
0
0
1
1
2
2
3
3
4
4
8
8
Server
Server
Fig. 4-3: SDO Protokoll
g012405x
4.3.1.2.1.2 Download SDO Protocol
This protocol is used to write data from the master into the bus coupler.
4.3.1.2.1.2.1
Initiate SDO Download
This protocol is used to initiate the data transmission from the master to the
bus coupler. When transmitting data of max. 4 bytes, these are also transmitted
within the protocol.
