Chapter 3. Program Data
30
PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual
GFK-2950C
3.1
Variables
A variable is a named storage space for data values. It represents a memory location in the target
PACSystems CPU.
A variable can be mapped to a reference address (for example, %R00001). If you do not map a
variable to a specific reference address, it is considered a
symbolic variable
. The programming
software handles the mapping for symbolic variables in a special portion of PACSystems user space
memory.
The kinds of values a variable can store depend on its data type. For example, variables with a UINT
data type store unsigned whole numbers with no fractional part. Data types are described in
Program Functions Handle Numerical Data
In the programming software, all variables in a project are displayed in the Variables tab of the
Navigator. You create, edit, and delete variables in the Variables tab. Some variables are also created
automatically by certain components (such as TIMER variables when you add a Timer instruction to
ladder logic). The data type and other properties of a variable, such as reference address are
configured in the Inspector.
For more information about
system variables,
which are created when you create a target in the
programming software, refer to
3.1.1
Mapped Variables
Mapped (manually located) variables are assigned a specific reference address. For details on the
types of Reference Memory and their uses, refer to
Summary of Contents for PACSystems RSTi-EP
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