Omron NX-EC0222 User Manual

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5 I/O Refreshing Methods
NX-series Position Interface Units User’s Manual (W524)
5-2 I/O Refreshing Methods
5
5-2-3 I/O Refreshing Method Operation
The I/O refreshing method between the EtherCAT Coupler Unit and the Position Interface Units
depends on the Enable Distributed Clock setting in the EtherCAT Coupler Unit.
Free-Run refreshing is always used as the I/O refreshing method between the EtherNet/IP Coupler Unit
and the Position Interface Units. There is no setting for the I/O refreshing method.
This section describes the operation of the following I/O refreshing methods: Free-Run refreshing, syn-
chronous I/O refreshing, and task period prioritized refreshing.
With Free-Run refreshing, the refresh cycle of the NX bus and the I/O cycle of the NX Units operate
asynchronously.
Additional Information
The Position Interface Unit cannot be assigned as an axis when Free-Run refreshing is used
(distributed clock disabled).
Free-Run refreshing operates as follows:
• The Communications Coupler Unit refreshes the I/O of the NX Units in order. (Refer to figure (a) in
the diagram below.)
• When the I/O is refreshed, the NX Unit reads the inputs and updates the outputs. (See following fig-
ure (b).)
• When the I/O is refreshed, the Communications Coupler Unit reads the most recent input values and
the NX Units control the outputs with the most recent output values. However, I/O is refreshed in
order, so even within the same Slave Terminal, the timing of reading inputs and updating output is not
the same for all of the NX Units. (See following figure (c).)
• The I/O refreshing interval changes according to the processing conditions of the Communications
Coupler Unit and host communications master. Therefore, the interval for reading inputs and updat-
ing outputs for NX Unit is not constant. (See following figure (d).)
• To read the correct input values, the input must be set before the input read timing of the NX Units for
the total time of the ON/OFF response time and input filter time.
EtherCAT Coupler Unit
Enable Distributed Clock setting
in the EtherCAT Coupler Unit
Position Interface Units
Enabled (DC for synchronization) Operates with synchronous I/O refreshing
Enabled (DC with priority in cycle time) Operates with task period prioritized
refreshing.
*1
*1. Unit version 1.2 or later and an NX-ECC203 EtherCAT Coupler Unit are required to use task period pri-
oritized refreshing. If you use unit version 1.1 or earlier and an NX-ECC203 EtherCAT Coupler Unit,
operation is performed with synchronous I/O refreshing.
Disabled (FreeRun) Operates with Free-Run refreshing
EtherNet/IP Coupler Unit
5-2-3 I/O Refreshing Method Operation
Operation of Free-Run Refreshing

Omron NX-EC0222 Specifications

General

Brand	Omron
Model	NX-EC0222
Category	Controller
Language	English