Lenze 931K - Manual (Page 31)

CANopen over EtherCAT (CoE)
Parameter data transfer
Differences in the state machine under CANopen and EtherCAT
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31 KHB 13.0005−EN 1.0
8.4 Parameter data transfer
All data of an SDO transfer in the case of CoE are transmitted via SDO frames.
Structure of an EtherCAT SDO frame
Mailbox
Header
CoE
Header
SDO control
byte
Index Subindex Data Data
6 bytes 2 bytes 1 byte 2 bytes 1 byte 4 bytes 1 ... n bytes
SDO frame area Description
Mailbox Header Data for mailbox communication ( length, address, and type )
CoE Header Identification of the CoE service
SDO control byte Identification for a read or write command
Index Main index of the CANopen communication object
Subindex Subindex of the CANopen communication object
Data Data contents of the CANopen communication object
Data (optional) Further optional data
This option is not supported by the 931K servo position controller since only
standard CANopen objects can be addressed.
The maximum size of these objects is 32 bits.
In order to transmit a standard CANopen object via such an SDO frame, the actual
CANopen SDO frame is packed and transmitted within an EtherCAT SDO frame.
Standard CANopen SDO frames can be used for:
ƒ Initialisation of the SDO download
ƒ Download of the SDO segment
ƒ Initialisation of the SDO upload
ƒ Upload of the SDO segment
ƒ Abort of the SDO transfer
ƒ SDO upload expedited request
ƒ SDO upload expedited response
)
Note!
All transfer types specified above are supported by the 931K servo position
controller.
Since only the standard CANopen objects the size of which is limited to 32 bits
(4 bytes) can be addressed if the CoE implementation of the 931K is used, the
transfer types are only supported up to a maximum data length of 32 bits (4
bytes).