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4 Understanding Programming
CP1E CPU Unit Software User’s Manual(W480)
4-2 Tasks, Sections, and Symbols
4
4-2-3 Overview of Symbols
Addresses are allocated to symbols using one of the following methods.
• User Specified allocation
• Automatic allocation using the CX-Programmer
The area of memory used for automatic allocations is set by selecting Memory Allocation - Auto-
matic Address Allocation from the PLC Menu in the CX-Programmer.
Note “Global” and “local” indicate only the applicable scope of the symbol.
They have nothing to do with the applicable scope of memory addresses.
Therefore, a warning but not an error will occur in the following cases, and it will be possible to
transfer the user program.
• The same addresses is used for two different local symbols.
• The same addresses is used for a global symbol and a local symbol.
Additional Information
In programs in the CX-Programmer, global symbols and local symbols can be identified by the
following character colors and symbol icons.
Select Tools - Options, and select Local Symbols or Global Symbols in Appearance to change
the color.
Types of sym-
bols
Project tree in the
CX-Programmer
Scope
Address and I/O
comment (with-
out a symbol
name)
Access
using sym-
bols from a
network
Access
from other
tasks
Access
from the
local task
Global
symbols
PLC tree Not
possible.
Possible. Possible. Supported
Local
symbols
Program tree Not
possible.
Possible. Not supported
Classification Display color Example (default color)
Global symbols Black (default)
Local symbols Blue (default)
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