Operation of I/O Refreshing with NX-series CPU Units
The following shows the operation of I/O refreshing when the built-in EtherCAT port on the NX-series
CPU Unit is used for communications with an EtherCAT Slave Terminal.
• The process data communications cycle in item (b) and the refresh cycle of the NX bus in item (c)
are automatically synchronized with the primary period or the task period of the priority-5 periodic
task of the CPU Unit in item (a).
*1
• The refresh cycle of each NX Unit in item (d) depends on the I/O refreshing method which is given
below.
*1. This applies when the distributed clock is enabled in the EtherCAT Coupler Unit.
The priority-5 periodic task must be supported by the connected CPU Unit model. Refer to the
NJ/NX-
series CPU Unit Software User's Manual (Cat. No. W501)
for information on the periodic tasks sup-
ported by each NX-series CPU Unit model.
Operation of I/O Refreshing with NJ-series CPU Units or NY-series
Industrial PCs
The following shows the operation of I/O refreshing when the built-in EtherCAT port on the NJ-series
CPU Unit or NY-series Industrial PC is used for communications with an EtherCAT Slave Terminal.
• The process data communications cycle in item (b) and the refresh cycle of the NX bus in item (c)
are automatically synchronized with the primary period of the CPU Unit or Industrial PC in item (a).
*1
• The refresh cycle of each NX Unit in item (d) depends on the I/O refreshing method which is given
below.
*1. This applies when the distributed clock is enabled in the EtherCAT Coupler Unit.
5-1-3
Calculating the I/O Response Time of NX Units
Depending on where the NX Unit is connected, refer to the following manuals to calculate the I/O re-
sponse times of an NX unit.
Connected to a CPU Unit
Manual for reference
Description
Software user’s manual for the connected
CPU Unit
The method for calculating the I/O response times of NX Units
in the CPU Rack with a CPU Unit is described.
NX-series Data Reference Manual
The NX Unit parameter values used for calculating the I/O re-
sponse times of NX Units are described.
Connected to a Communications Coupler Unit
Manual for reference
Description
User’s manual for the connected Communica-
tions Coupler Unit
The method for calculating the I/O response times of NX Units
on Slave Terminals is described.
5 I/O Refreshing
5 - 4
NX-series Analog I/O Units User’s Manual for High-speed Analog Input Units (W592)
