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MELSEC-Q
10 DEVICES
10.7 File Registers (R)
(1) Definition
(a) File registers are expansion devices for data registers.
(b) File register data is stored in files in the standard RAM, the memory card.
Refer to the table as follows:
CPU Module Type
Number of File Registers
Q02CPU
32k points
Q02HCPU, Q06HCPU
64k points
Q12HCPU, Q25HCPU
128k points
Use a memory card to store much more points if necessary.
K100 R2
MOV
"100" is written to R2.
Standard RAM/Memory card
File register
R0
R1
R2
(c) File registers, which consist of 16 bits per point, read and write data in 16bit
units.
Rn
b15
b0
(d) If the file registers are used for 32-bit instructions, the data will be stored in
registers Rn and Rn + 1.
The lower 16 bits of data are stored in the file register No. (Rn) designated
in the sequence program, and the upper 16 bits of data are stored in the
designated file register No.+ 1.
For example, if file register R2 is designated in the DMOV instruction, the
lower 16 bits are stored in R2, and the upper 16 bits are stored in R3.
D0
R2
DMOV
R3
Upper 16 bits Lower 16 bits
R2
Processing object: R2, R3
Two file registers can be used to store numeric data from -2147483648 to
2147483647 or from 0
H
to FFFFFFFF
H
.
(e) The content of the file register is retained even when the power is turned off
or reset. (It is not initialized even if latch clear is performed.)
Use a sequence program to initialize the file register when the power is
turned off or reset.
For example, to clear the R0 to R2047 file registers upon power-on of the
PLC, write "0" using an FMOV instruction.
