431
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
15 External FX I/O Device – FNC 70 to FNC 79
15.10 FNC 79 – TO / Write To A Special Function Block
11
FN
C30-
FN
C39
R
o
ta
tion and
Sh
ift
12
FNC
4
0
-FNC49
D
a
ta
Op
e
ra
tio
n
13
FNC5
0
-FNC5
9
H
igh Speed
Pr
ocessi
ng
14
FM
C6
0
-F
NC6
9
H
and
y
In
st
ru
cti
o
n
15
FNC7
0
-FNC7
9
Ex
te
rn
a
l F
X
I
/O
D
evi
ce
16
FNC8
0
-FNC8
9
Ext
e
rnal
FX
D
evi
ce
17
F
N
C1
00
-F
NC
10
9
Da
ta
Tr
ansf
e
r 2
18
FN
C
110-FN
C
13
9
Fl
oat
ing P
o
in
t
19
FN
C
140-FN
C
149
Da
ta
O
per
at
io
n
2
20
FN
C
15
0-F
N
C
159
P
o
si
tioni
ng
C
ont
ro
l
15.10 FNC 79 – TO / Write To A Special Function Block
Outline
This instruction writes data from a PLC to buffer memories (BFM) in a special extension unit/block.
When a large capacity of data is written to buffer memories (BFM) by this instruction, a watchdog timer error
may occur. When splitting the data to be written does not affect the control, use WBFM (FNC279) instruction.
→
For WBFM (FNC279) instruction, refer to Section 31.2.
1. Instruction format
2. Set data
3. Applicable devices
Explanation of function and operation
1. 16-bit operation (TO and TOP)
→
For the common items between FROM instruction and TO instruction,
refer to Subsection 15.9.1.
PLC (word device)
→
Special extension unit/block (BFM)
"n"-point 16-bit data starting from
inside a PLC are transferred (written) to "n"-point buffer memories
starting from the buffer memory (BFM) # m2 inside a special extension unit/block No. m1.
Operand Type
Description
Data Type
m1
Unit number of a special extension unit/block
(K0 to K7 from the right side of the main unit)
16- or 32-bit binary
m2
Transfer destination buffer memory (BFM) number
16- or 32-bit binary
Device number storing the transfer source data
16- or 32-bit binary
n
Number of transfer points
16- or 32-bit binary
Oper-
and
Type
Bit Devices
Word Devices
Others
System User
Digit Specification
System User
Special
Unit
Index
Con-
stant
Real
Number
Charac-
ter String
Pointer
X Y M T C S D
.b KnX KnY KnM KnS
T
C
D
R U
\G
V
Z Modify K
H
E
"
"
P
m1
3 3
3 3
m2
3 3
3 3
3
3
3
3 3 3 3
3 3
3
n
3 3
3 3
P
FNC 79
TO
D
DTO
DTOP
Mnemonic
Operation Condition
32-bit Instruction
17 steps
Continuous
Operation
Pulse (Single)
Operation
16-bit Instruction
9 steps
Mnemonic
Operation Condition
Continuous
Operation
Pulse (Single)
Operation
TO
TOP
S
S
S
Command
input
FNC 79
TO
m1
m2
n
S
Unit No.
m1 = 0 to 7
Transfer source BFM #
m2 = 0 to 32766
Transfer destination
Number of transfer points
n = 1 to 32767