Ethernet Header
14 Byte
EtherCAT Frame Header
2 Byte
Ethernet FCS
4 Byte
EtherCAT Protocol Data
… Byte
EtherCAT Frame [ETG]
Ethernet Frame [IEEE 802.3]
Ether type:
0x88A4 =EtherCAT
Type:
4= Process data communication
5= Mailbox communication
1st Process Data
… Byte
Process Data Frame Header
12 Byte
PDO Header
8 Byte
PDO
(PDO Mapping: 0x1600/0x1A ...)
… Byte
Mailbox Header
6 Byte
Error Code
2 Byte
Data
1 … 5 | 6 … n Byte
CoE Data
… Byte
CoE Header
2 Byte
Type:
0x03= CoE
Service:
0x01= Emergency
0x02= SDO request
0x03= SDO response
0x08= SDO Information
Error Register
1 Byte
Process Data Object Frame
Process Data Frame
Mailbox Frame
Emergency Frame
SDO Request Frame/SDO Response Frame
SDO Information Frame
Index
2 Byte
Data
1 … 4 | 5 … n Byte
SDO control
1 Byte
Subindex
4 Byte
SDO Info Header
2 Byte
SDO Info Service Data
… Byte
Mailbox Header
6 Byte
EoE Header
3 Byte
Type:
0x02= EoE
EoE Data
… Byte
EoE Frame
Standard CANopen SDO Frame
Standard CANopen Emergency Frame
Standard CANopen PDO Frame
CoE Frame
Fig. 105 Layout of the Ethernet and EtherCAT frame
11.4
EtherCAT final state machine
The EtherCAT final state machine contains all statuses needed to establish CMMT communication in
an EtherCAT network. After a reboot (Power ON or Reset), the CMMT is initialized by the controller
(Master). In the following sequence, communication is established for mailbox data and process data.
EtherCAT
520
Festo — CMMT-ST-SW — 2019-02
Summary of Contents for CMMT-ST-SW
Page 615: ......
