232
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
9 Move and Compare – FNC 10 to FNC 19
9.6 FNC 15 – BMOV / Block Move
9.6.1
Function of transfer between file registers and data registers
BMOV (FNC 15) instruction has a special function for file registers (D1000 and later).
→
For the details of file registers, refer to Section 4.8.
1. What are file registers
By parameter setting, D1000 to D7999 can be handled as file registers, and written to and read from the
program memory area.
1) Outline of setting
File registers (D1000 to D7999) do not exist in the initial status. They are valid only when some number
of file registers are secured by parameter setting in a programming tool.
2) Number of file registers
In parameter setting, set 500 file registers as 1 block.
1 to 14 blocks (each of which has 500 file registers) can be set.
1 block occupies 500 steps in the program memory area.
3) Difference between BMOV (FNC 15) instruction and other instructions
The table below shows the difference between BMOV (FNC 15) instruction and other instructions with
regard to file registers (D1000 and later).
When restoring the power, data registers set as file registers are automatically copied from the file
register area [A] to the data register area [B].
Instruction
Contents of transfer
Remarks
BMOV
instruction
Can read from and write to the file register
area [A] inside the program memory.
−
Other applied
instructions
Can read from and write to the data register
area [B] inside the program memory in the
same way as general data registers.
Because the data register area [B] is provided
inside the system RAM in PLCs, its contents can be
arbitrarily changed without regard to the optional
memory format.
Data register
[B]
Inside system
RAM
Inside built-in memory
or memory cassette
Program
memory
Program/
comment
File register
[A]
D1000
500 points
×
14 blocks
maximum
(7000 points
maximum)
When power
is turned ON
When PLC
mode is
changed from
STOP to
RUN
Data
memory
Data register
Data register
D7999
D1000
D 0
Read
Write
Remaining area can be used as latched (battery backed)
type registers for general purpose.
Devices D1000 and later specified as
operands in applied instructions
except FNC 15 (BMOV), indirectly
specified values for timers or
counters or devices in RST
instruction are read from and written
to the area [B] in the same way as
general data registers.
