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5 I/O Refreshing Methods
NX-series Position Interface Units User’s Manual (W524)
5-1 I/O Refreshing for Slave Terminals
5
The operation of I/O refreshing is as follows when the built-in EtherCAT port on the NJ-series CPU Unit
is used for communications with an EtherCAT Slave Terminal.
• The (b) process data communications cycle and (c) refresh cycle of the NX bus in the above figure
are automatically synchronized with the (a) task period of the primary periodic task in the CPU Unit if
the distributed clock is enabled in the EtherCAT Coupler Unit.
• The (d) refresh cycles of the NX Units depend on the I/O refreshing methods, which are described
later.
Refer to the NX-series EtherCAT Coupler Unit User’s Manual (Cat. No. W519-E1-05 or later) for
detailed information on I/O refreshing between the built-in EtherCAT port on an NJ/NX-series CPU Unit
and EtherCAT Slave Terminals.
• You can use the priority-5 periodic task only on NX-series CPU Units.
• With an NX-series CPU Unit, you can perform process data communications in two tasks: the
primary periodic task and the priority-5 periodic task.
• With an NJ-series CPU Unit, you can perform process data communications only in the pri-
mary periodic task.
NJ-series CPU Units and I/O Refresh Operation