Ring Topology - Omron Sysmac NJ Series User Manual

4 EtherCAT Network Wiring
4-1-3

Ring Topology

This topology uses Junction Slaves to connect slaves in a ring.
This section describes the features, components, and precautions for the ring topology.
Version Information
Project unit version 1.40 or later and Sysmac Studio version 1.29 or higher are required to use
the ring topology.
Features of Ring Topology
In a ring topology, the master can continue the normal communications with all the slaves even if there
is only one point of disconnection in the communications cables.
If disconnection occurs at a point between Slave #1 and Slave #2 as shown in the figure below, in
Slave #1, the output port is closed, but communications frames return at the input port. The communi-
cations frames then flow via the Junction Slave into Slave #3 and return at the output port of Slave #2.
This enable the master to continue the normal communication.
EtherCAT master
4-4
Flow of communications frames

Ring topology

Junction Slave
Slave #1
Discon-
Slave #2
nection
Slave #3
NJ/NX-series CPU Unit Built-in EtherCAT Port User's Manual (W505)
Return
Closed
Return
Input port
Output port