Omron NX-SID800 User Manual

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7 Programming
NX-series Safety Control Unit User’s Manual (Z930)
7-2 Variables
7
7-2-3 Types of User-defined Variables
A local variable can be read and written only inside the POU (program or function block) in which it is
defined. “Local variables” is the generic term for internal variables, input variables, output variables,
and external variables.
 Internal Variables
An internal variable can be used only within one POU.
An internal variable is declared in the local variable table of the POU.
You cannot access the values of internal variables from outside of the POU.
You can declare an internal variable with the same name in different POUs. In this case, memory is
allocated separately for each variable.
 Input Variables
When a POU is called, the values of the input parameters are assigned to the input variables from
the calling POU. An input variable is declared in the local variable table of the POU.
 Output Variables
Before processing a POU is completed, the output parameters returned to the calling POU are
assigned to the output variables. An output variable is declared in the local variable table of the
POU.
 External Variables
External variables are used to access global variables from a POU.
You declare global variables in the global variable table.
Device variables that are automatically created from the Slave Terminal configuration are automatically
registered as global variables.
Local Variables
Global Variables

Omron NX-SID800 Specifications

General

Brand	Omron
Model	NX-SID800
Category	Controller
Language	English