I/O Refreshing From Cpu Units To Nx Units; I/O Refreshing - Omron NX-ID User Manual

5 I/O Refreshing

5-1 I/O Refreshing
This section describes I/O refreshing for NX Unit.
5-1-1

I/O Refreshing from CPU Units to NX Units

An NX-series NX1P2 CPU Unit cyclically performs I/O refreshing with the NX Units.
The following period and two cycles affect operation of the I/O refreshing between the CPU Unit and the
NX Units.
(a) Primary period in CPU Unit
(b) Refresh cycle of the NX bus
(c) Refresh cycle of each NX Unit
CPU Unit
(a) Primary
period in CPU
Unit
Data exchange between the
user program and I/O Units
The following operation occurs.
• The refresh cycle of the NX bus in item (b) is automatically synchronized with the primary period of
the CPU Unit in item (a).
• The refresh cycle of each NX Unit in item (c) depends on the I/O refreshing method which is given
below.
Refer to the NJ/NX-series CPU Unit Software User's Manual (Cat. No. W501-E1-16 or later) for
detailed information on I/O refreshing between the NX1P2 CPU Unit and the NX Units.
Refer to the NJ/NX-series CPU Unit Software User's Manual (Cat. No. W501-E1-16 or later) for the I/O
response times of NX Units in a CPU Rack.
5 - 2
NX Unit NX Unit NX Unit
(b) Refresh cycle of the NX bus
(c) Refresh cycle of each NX Unit
NX-series Digital I/O Unit User's Manual (W521)