Mitsubishi Electronics FX3G User Manual

Page of 964
259
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
 Series
Programming Manual - Basic & Applied Instruction Edition
9 Move and Compare – FNC 10 to FNC 19
9.6 FNC 15 – BMOV / Block Move
1
Introdu
ction
2
Ov
ervi
ew
3
Instruction 
Li
st
4
D
evices 
in Det
ai
l
5
Specifi
ed the
De
vice
 &
 
C
onst
ant
6
Bef
ore
 
Pr
og
ra
mmi
ng
7
Bas
ic 
Instruction
8
FN
C00-FN
C0
9
Program Fl
ow
9
FNC
10-FN
C19
Mov
e & Com
pare
10
FNC
20-FNC
29
Arith. & Lo
gi
Operati
on
5) Handling of the memory cassette
When changing the contents of file registers secured inside the memory cassette, confirm the following
conditions:
- Set the protect switch of the memory cassette to OFF.
- Do not turn OFF the power while the contents of file registers are changed. 
If the power is turned OFF during the change, the data stored in file registers may be filled with unexpected 
values, or a parameter error may occur.
6) Execution time for writing data to file registers
- In  FX
3U
/FX
3UC
 PLCs
It takes 66 to 132 ms to write data in one continuous block (500 points) to the memory cassette (flash memory).
Execution of the program is paused during this period. Because the watchdog timer is not refreshed during this 
period, it is necessary to take proper countermeasures such as inserting the WDT instruction into the sequence 
program.
It takes longer time to write data to file registers stored in a memory cassette (flash memory) compared to writing 
data to file registers stored in the built-in memory.
- In  FX
3S
/FX
3G
/FX
3GC
 PLCs
It takes 80 ms to write data in one continuous block (500 points) to file registers.
Note that execution of the program is paused during this period, but the watchdog timer is automatically 
refreshed.
The time for writing data is same between file registers stored in the built-in memory and file registers stored in a 
memory cassette (EEPROM).
7) Allowable number of times of writing to the memory
Data can be written to the memory cassette up to 10,000 times, and to the memory (EEPROM) built in FX
3S
/
FX
3G
/FX
3GC
 PLCs up to 20,000 times.  
When a continuous operation type instruction is used for data writing in a program, data is written to the memory
in every operation cycle of the PLC.  To prevent this, make sure to use a pulse operation type instruction
(BMOVP).
8) File register operation
File registers are secured inside the built-in memory or memory cassette.
Different from general data registers, file registers can be read and written only by peripheral equipment or BMOV
(FNC 15) instruction.
9) If a file register is not specified as the destination in BMOV (FNC 15) instruction, the file register is not accessed.
a) Outline of memory operation
b) Program example
When X000 is set to ON, the data register area [B] is read.
A file register can be specified as 
.  But if the same number with 
 is specified, the same-number
register update mode is selected.
However, even if a file register having different number is specified for 
 and 
 respectively, data
cannot be transferred from the file register area to another file register area.  In such a case, read the contents
of a file register specified as 
 in the same-number register update mode to the data register area [B]
once, and then write the data.
→ For the same-number register update mode of file registers, refer to Subsection 4.9.4.
Data register
[B]
Inside system
RAM
Inside built-in memory 
or memory cassette
Program
memory
Program/
comment
File register
[A]
D1000
Image
memory
Data register
Data register
D7999
D599
D 0
D200
Read
D1499
D1100
500 points 
×
14 blocks
maximum
(7000 points
maximum)
X000
FNC 15
BMOVP
D1100
D200
K400
n
   
D
   
S
   
S
   
D
   
S