Accessing I/O; Types Of Variables - Omron NJ-series User Manual

2 CPU Unit Operation
2-3

Accessing I/O

The CPU Unit uses variables to access I/O. This section describes how variables are used to access
I/O.
In this manual, I/O on EtherCAT slaves and CJ-series Units are treated as I/O. Refer to the NJ-series
CPU Unit Built-in EtherNet/IP Port User's Manual (Cat. No. W506) for details on how to access data in
other Controllers with tag data links.
2-3-1

Types of Variables

In an NJ-series CPU Unit, you use variables in the user program to access I/O and memory in the CPU
Unit.
The type of a variable depends on whether it has attributes that are set by the user, and what it can
access.
User-defined variables
Semi-user-defined
variables
System-defined
variables
*1 Refer to Device Variable Attributes on page 3-11 for the attributes that can be set.
*2 "EtherCAT slaves" includes any NX Units on EtherCAT Slave Terminals.
*3 With the Sysmac Studio version 1.09 or higher, the EtherCAT slaves to which axes are assigned can also be
accessed via EtherCAT slave device variables.
User-defined Variables
The user defines all of the attributes of a user-defined variable. Refer to 6-3 Variables for details on
user-defined variables.
2-10
Variables
Device variables Device variables
for EtherCAT
slaves
Device variables
for CJ-series
Units
Cam data variables
System-defined variables for PLC
Function Module
System-defined MC Common
variables for Variable
motion control
Axis Variables
Axes Group Vari-
ables
System-defined variables for Ether-
Net/IP
System-defined variables for Ether-
CAT master
Attribute set-
Accessed data
tings
All attributes can CPU Unit
be set.
Some attributes EtherCAT slaves to which axes
*1
can be set. are not assigned
CJ-series Basic I/O Units and
CJ-series Special Units
Servo Drives, encoder input
slaves, and CPU Unit
No attributes can CPU Unit
be set.
Servo Drives, encoder input
slaves, and CPU Unit
Built-in EtherNet/IP port
Built-in EtherCAT master port
NJ-series CPU Unit Software User's Manual (W501)
*2*3