1-7
Section 1 Specifications
1-3-3 Standard memory area
The standard memory area is used for auxiliary relays that are used internally in the PLC.
G
Key points:
1) In the direct addressing mode, this memory area is specified in he format of %M
o
1. ... (replace o with any of X, W, or D).
Usually, since a variable declaration is used to assign memory to an application program, you may neglect addresses in
programming. See “1-5 variables” for details.
2) The specified memory area is reset to (0) zero when self-PLC is started.
3) 4K words from the top of the standard memory is the area where data access in the CPU is processed at high speed.
4) The sizes of the standard memory areas can be changed taking those of other areas into account. Note that the size of
the high-speed access memory area is fixed to 4K words and cannot be changed.
For the details of memory size change, see “3-3-2 CPU memory size definition.”
5) No continuous access is allowed to the high-speed access memory area and the boundaries between other areas.
For example, an array or structure cannot lie across the boundary
………………………………
……
%MW1.0
%MW1.4095
%MW1.4096
Standard memory
(high speed)
(M)
4K words
Standard memory
(M)
Unit with 14/24 points
: 0K word
Unit with 32/40/60 points
: 4K words
15……………………………0
IEC representation
