Applied Motion ST10-C-CE - Manual (Page 91)

91 920-0025 Rev K
3/5/2015
CANopen User Manual
Appendix J - SDO and PDO Access
Enable SDO Use
To enable Service Data Object (SDO) use, the NMT state must be either Pre-Operational
or Operational. Send an NMT message to put the node into either state. When completed,
the heartbeat should return either 127 (Pre-Operational) or 5 (Operational). The drive is now
ready to read and/or write all OD entries.
Building an SDO Read Data Frame - Example
This example will show how to read the heartbeat time of node 2E
h
. An SDO read request
must be sent to the drive. The default COB-ID for SDO requests is 600
h
(see CiA 301), plus
the Node-ID of 2E
h
. This results in a specific COB-ID for this message of 62E
h
. The first data
byte is reserved for the control byte, which is always 40
h
for an SDO Read. The next 2 bytes
are reserved for the OD entry address in Little Endian format. To obtain OD entry 1017, we
stuff data byte 1 with 17
h
and data byte 2 with 10
h
. Data byte 3 is reserved for the sub-index
of the OD entry, which in this case is zero. The last 4 bytes are unused for SDO reads. The
whole message appears as:
Table 27: Enable SDO Use
The drive will respond with a message with COB-ID 580
h
+ Node ID, or 5AE
h
.
For more information: see CiA 301, SDO protocol
PDO Access
Enable PDO Use
To enable Process Data Object (PDO) use, the NMT state must be set to Operational and
an NMT message sent to enable the Operational state. When completed, the heartbeat should
return a 5. The drive is now ready to receive RPDOs, and will transmit TPDOs depending on
the Transmission Type.
COB-ID Data Length Data Byte 0 1 2 3 4 5 6 7
62E
h
8 40
h
17
h
10
h
00
h
00
h
00
h
00
h
00
h
DATA BYTES