Omron NX-SID Series User Manual page 54

1 Overview
 Relationship between Master and Slaves during Standard Process Data Com-
munications
The following figure shows the EtherCAT master/slave relationship during standard process data
communications.
M
NJ/NX-series
CPU Unit
The NJ/NX-series CPU Unit performs standard process data communications with the Safety CPU Unit
and the Safety I/O Units on the EtherCAT network.
In this relationship, the NJ/NX-series CPU Unit operates as the master in the standard process data
communications. Meanwhile, the Safety CPU Unit and Safety I/O Units operate as slaves in the stan-
dard process data communications. The NJ/NX-series CPU Unit cannot output signals to Safety I/O
Units.
Relationships for EtherNet/IP Network Communications
 Relationships for Safety Process Data Communications
The relationships for safety process data communications are shown in the following figure.
Standard
CPU Unit
EtherNet/IP
The Safety CPU Unit performs safety process data communications with the Safety I/O Units on the
same Slave Terminal.
Safety process data communications are not performed with Safety I/O Units on other Slave Termi-
nals on the EtherNet/IP network. Here, the Safety CPU Unit operates as the master in the safety
process data communications. Meanwhile, the Safety I/O Units operate as slaves in the safety pro-
cess data communications.
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S S S
Coupler
Safety
Unit
CPU
Unit
Coupler
Unit
Safety Control System
M
S M S
S
Coupler
Safety
Unit
CPU
Unit
S
Coupler
Unit
M Standard master
Standard slave
S
Standard process data communications
EtherCAT
S S
Safety master
Safety slave
Safety process data communications
M S
Safety
CPU
Unit
NX-series Safety Control Unit User's Manual (Z930)