5 - 3
5 I/O Refreshing
NX-series Analog I/O Units User’s Manual for Analog Input Units and Analog Output Units (W522)
5-
1 I/O Refresh
ing
5
5-
1-2 I/O Refr
eshing
from CPU U
nit
s
or
Industrial PC
s to Slave T
er
m
in
al
The CPU Unit or Industrial PC cyclically performs I/O refreshing with the Slave Terminal through the
Communications Master and Communications Coupler Units.
The following four cycles affect operation of the I/O refreshing between the NX Unit on a Slave Terminal
and the CPU Unit or Industrial PC.
(a) Cycle time of the CPU Unit or Industrial PC
(b) Communications cycle of the host network
(c) Refresh cycle of the NX bus
(d) Refresh cycle of each NX Unit
The cycle time of the CPU Unit or Industrial PC and communications cycle of the host network and the
I/O refresh cycle of the NX bus are determined by the CPU Unit or Industrial PC types and the
communications types.
The following explains operations when the built-in EtherCAT port on the NJ/NX-series CPU Unit or
NY-series Industrial PC is used for communications with an EtherCAT Slave Terminal, with symbols in
the figure.
Refer to the user’s manual for the connected Communications Coupler Unit for details on the operation
of I/O refreshing on Slave Terminals other than EtherCAT Slave Terminals.
5-1-2
I/O Refreshing from CPU Units or Industrial PCs to Slave Termi-
nal
Data exchange between the
user program and I/O Units
Communications Master Unit
CPU Unit or
Industrial PC
(a) Cycle
time
(b) Communications cycle of the host network
(c) Refresh cycle of the NX bus
Communi-
cations
Coupler
Unit
NX Unit
NX Unit
NX Unit
Communications path
Other communications
slaves
(d) Refresh cycle of each NX Unit
Slave Terminal
Summary of Contents for NX-AD series
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