ElmoMC CANopen DS 301 Implementation Guide - Manual (Page 28)

The server response is outlined in the following table:
Byte Value Description Comment
0 %01000011 Header Bits 7…5: %010 is client command specifier
(css) for Initiate Domain Upload.
Bits 3, 2: n bits that indicate that all data
bytes are relevant.
Bits 1, 0: %11, to expedite transfer and d
contains information.
1 0x00 Index (LO)
2 0x10 Index (HI) Use little endian.
3 0 Sub-index No sub-index, so it is set to 0.
4 0x92 Data: 0x00020192 in
little endian format
5 0x01
6 0x02
7 0
Table 4-3: Expedited SDO - Server Response
4.7 Downloading Data Using an SDO
Data downloading with SDOs is very similar to data uploading. It can be handled in a
single message conversation (expedited transfer) or in a segmented conversation. A
detailed example of an expedited download transfer is given in
section 5.3.6 .
4.8 Error Correction
Included in an SDO transaction are features that enable error detection and correction.
Errors can be detected with both software and hardware. Hardware error conditions
relate to overrun, excessive line noise, broken lines or other malfunctions of the physical
layer. The toggle bit is used for software detection; it correlates each domain segment
with its previous and next segments. An unexpected toggle bit signals an error.
An Elmo slave that receives a corrupted message always terminates the SDO sequence
with an “Abort domain transfer” message, structured as follows:
CANopen DS 301 Implementation Guide Service Data Objects (SDOs)
MAN-CAN301IG (Ver. 2.1)
4-8