Introduction To Ethercat; How Ethercat Works - Omron NX-ECC201 User Manual

1 EtherCAT Networks
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Introduction to EtherCAT

EtherCAT (Ethernet Control Automation Technology) is a high-performance industrial network system
that enables faster and more efficient communications based on Ethernet.
Each node achieves a short communications cycle time by transmitting Ethernet frames at high speed.
Although EtherCAT is a unique communications protocol, standard Ethernet technology is used for the
physical layer, which means you can use Ethernet cables for wider application.
And the effectiveness of EtherCAT can be fully utilized not only in large control systems that require
high processing speeds and system integrity, but also in small and medium control systems.
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How EtherCAT Works

With EtherCAT, Ethernet frames pass through all of the slave nodes.
When a frame passes through a slave node, the slave node reads and writes the data in the area that is
allocated to it in the frame in a few nanoseconds.
The Ethernet frames that are transmitted by the EtherCAT master pass through all EtherCAT slaves
without stopping. The last slave returns all of the frames, which again pass through all of the slaves
before returning to the EtherCAT master.
This mechanism ensures high speed and realtime data transmission.
EtherCAT master
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Slave Slave
Data
OUT IN
• The slave reads output data addressed to it.
• The slave writes input data.
Ethernet frames
NX-series EtherCAT Coupler Unit User's Manual (W519)
Slave