Omron E3NX-FA Operation Manual page 21

It is the "EtherCAT telegram" stored directly in an Ethernet frame that exchanges data regularly
between the EtherCAT Master Unit and Slave Units.
Each "EtherCAT telegram" is configured with telegram header (data length, including address of one or
more Slave Units, etc.), data, working counter (check bit).
When an Ethernet frame is compared to a "train", an EtherCAT telegram can be considered as "railway
car."
Ethernet
header
EtherCAT
header
1st EtherCAT 2nd EtherCAT
telegram
Telegram
header
E3NW-ECT EtherCAT Digital Sensor Communication Unit Operation Manual (E429)
Ethernet frame
Ethernet data (Maximum 1498 bytes)
1...n EtherCAT telegram
telegram
Data
. . . . .
n th EtherCAT
telegram
WKC
WKC : Working counter
1 EtherCAT Network
CRC
EtherCAT frame
1 - 3
1