
EtherCAT Information
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TR-Electronic GmbH 2010, All Rights Reserved
10/07/2013
TR - ECE - BA - DGB - 0080 - 05
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4.7.1 CANopen over EtherCAT protocol
4.7.1.1 Initiate SDO Download Expedited Request
Write, Client --> Server
Frame Fragment
Data field
Data type
Value / Description
Mailbox Header
Length
WORD
0x0A: Length of the mailbox service data
Address
WORD
Source station address, if Master = Client
Destination station address, if Slave = Client
Channel
unsigned:6
0x00, reserved
Priority
unsigned:2
0x00: Lowest priority
…
0x03: Highest priority
Type
unsigned:4
0x03: CANopen over EtherCAT (CoE)
reserved
unsigned:4
0x00
CANopen Header
Quantity
unsigned:9
0x00
reserved
unsigned:3
0x00
Service
unsigned:4
0x02: SDO Request
SDO
Comm
and
code (CCD
)
Size indicator
unsigned:1
0x00: Size of data (1..4) not specified
0x01: Size of data specified in data record size
Transmission type
unsigned:1
0x01: Expedited transmission
Data record size
unsigned:2
0x00: 4 byte of data
0x01: 3 byte of data
0x02: 2 byte of data
0x03: 1 byte of data
Total access
unsigned:1
0x00
Command
unsigned:3
0x01: Initiate Download Request
Index
WORD
Object index
Sub-index
BYTE
Object sub-index
Data
BYTE[4]
Object data
Table 1: CANopen Initiate SDO Download Expedited Request
The following SDO write frames can be derived from the above protocol:
CCD
Meaning
Valid for
0x23
Write 4 byte
SDO Request
0x27
Write 3 byte
SDO Request
0x2B
Write 2 byte
SDO Request
0x2F
Write 1 byte
SDO Request