3 Protocol description
15-04-2016 21 7000.05052
3.3.2.2
SDO Block Download
The segmented SDO block download protocol is based on CiA301.
Fig. 7: Sequential diagram for the SDO block download
1) This is repeated until less than 58 bytes remain to be transmitted
Tab. 14: Request SDO Initiate Block Download (Master to Slave)
Byte
Contents
Description
1
Length
User data length >7 bytes
2
Node number
Node number
3
0x0B
Command SDO Block Write Init
4
Index LB
Index of the object entry LB
5
Index HB
Index of the object entry HB
6
Sub-index
Sub-index of the object entry
7
Data length LB
Overall length of the data to be transmitted in bytes LB
8
Data length HB
Overall length of the data to be transmitted in bytes HB
9–N
Data
Data of the first segment (max. 53 bytes)
(N+1)
CRC
Check sum
Master
Slave
optional
SeqNr = 0
[dataLen > 110]
Request_SDOBlockWriteInit(Index, Subindex, Data)
Response_SDOBlockWriteDownload(AckSeq)
Request_SDOBlockWriteDownload(SeqNr, Data)
Response_SDOBlockWriteInit(Index, Subindex,)
Response_SDOBlockWriteEnd(AckSeq)
Request_SDOBlockWriteEnd(SeqNr, Data)
SeqNr ++
(1)