I/O Refreshing From Cpu Units Or Industrial Pcs To Slave Terminal - Omron NX-ID User Manual

5-1-2 I/O Refreshing from CPU Units or Industrial PCs to Slave
Terminal
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
CPU Unit or
Industrial PC Communications Master Unit
Data exchange between the
user program and I/O Units
(a) Cycle
time
Slave Terminal
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.
NX-series Digital I/O Unit User's Manual (W521)
(b) Communications cycle of the host network
Communi- NX Unit NX Unit
cations
Coupler
Unit
(c) Refresh cycle of the NX bus
Communications path
NX Unit
Other communications
slaves
(d) Refresh cycle of each NX Unit
5 I/O Refreshing
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