ElmoMC CANopen DS 301 Implementation Guide - Manual (Page 23)

4.2 Download SDO Protocol
This protocol is used to implement the Download SDO Segment service.
Client to server:
0
1 8
7…5 4 3…1 0
css = 0 t n c seg-data (segment data)
Server to client:
0
1 8
7…5 4 3…0
scs = 1 t x reserved
where:
css
Client command specifier
0: Download segment request
scs Server command specifier
1: Download segment response
seg-data Maximum seven bytes of segment data downloaded. Encoding depends
on type of data referenced by index and sub-index.
n Number of bytes in seg-data that do not contain segment data. Bytes
[8-n, 7] do not contain segment data. n = 0 if no segment size is indicated.
c Whether or not there are still more segments to be downloaded:
0: More segments to be downloaded
1: No more segments to be downloaded
t Toggle bit, which alternates for each subsequent segment to be
downloaded. First segment has toggle-bit set to 0. Toggle bit is equal for
request and response message.
x Not used; always 0.
reserved Reserved for future use; always 0.
CANopen DS 301 Implementation Guide Service Data Objects (SDOs)
MAN-CAN301IG (Ver. 2.1)
4-3