Variables - Omron NA-series Startup Manual

2-2

Variables

A variable is like a container to store the I/O data exchanged with external devices and the temporal
data at internal processing. In the HMI, all the operations such as I/O data exchanging with external
devices or data arithmetic processing are performed through the variable. Therefore, it is possible to
create the HMI application that does not depend on memory addresses of hardware.
Each object on a Page accesses to the variables in global variable table of HMI as follows. There are a
variable (external variable) map onto global variable of the Controller and a variable (internal variable)
not to map onto it.
A Page
An object
Subroutine variable and global variable
A subroutine variable is readable and writable only within the subroutine. On the other hand, a global
variable is readable and writable from everywhere in the project. The application described in this guide
defines the variable accessing to pushbutton switch and lamp as global variable.
Data Type of Variable
Data type is property that defines the data format and the range of value expressed with a variable.
When the variable is defined, the data type should always be specified.
In the NA-series Programmable Terminal, the data type that is the same with the one of Visual Basic is
available. For details, refer to the NA-series Programmable Terminal Software User's Manual (V118).
NA-series Programmable Terminal Startup Guide (V120)
HMI
Global variable table of HMI
Access
Variable...external variable
new_Controller_0_SwGreen
Variable...external variable
new_Controller_0_SwYellow
Access
Variable...external variable
new_Controller_0_SwRed
Access
Variable...internal variable
abc
2 HMI Application Basics
Controller name on the project:
new_Controller_0
Global variable of the Controller
Mapping
Variable
SwGreen
Variable
SwYellow
Variable
SwRed
2
2 - 3