Mitsubishi Electric MELSEC FX3U Programming Manual page 560

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
3) When "n" is an odd number, only the low-order byte (8 bits) of the final separation source device is
regarded as the target data as shown in the figure below.
For example, when "n" is "5", the data from
to
D
b15
+0
S
+1
+2
4) When "n" is "0", WTOB instruction is not executed.
Related instruction
Instruction
BTOW (FNC142)
Caution
Devices storing the separation source data can overlap devices storing the separated data.
When "n" is an odd number, however, the high-order byte (8 bits) of the final separation source device is
overwritten and erased.
b15
=D12
S
D13
D14
Errors
An operation error is caused in the following cases; The error flag M8067 turns ON, and the error code is
stored in D8067.
• When the separation source devices
code: K6706)
When "n" is an odd number, the number of a rounded up value decides the number of devices. (error
code: K6706)
• When the separated data destination devices
(error code: K6706)
Program example
In the program shown below, the data stored in D10 to D12 is separated in byte units, and stored in D20 to
D25.
X000
b15
D10
D11
D12
558
+4.
D
b8 b7 b0
12H 39H
56H 78H
FEH DCH
It is ignored when
"n" is "5".
Combines the low-order 8 bits (low-order byte) of consecutive 16-bit data.
b8 b7 b0
32H 31H
34H 33H
36H 35H
"36H" is ignored when "n" is "5".
Because D14 is also used in the
separation result destination devices D
and later, "36H" is erased and
overwritten.
FNC141
D10 D20
WTOBP
b8 b7 b0
FDH 58H
57H E2H
34H 44H
to the low-order byte (8 bits) of
S
b15
+0
D
+1
+2
+3
+4
"00H" is stored.
Description
b15
=D12
D
D13
D14
D15
D16
"00H" is stored.
to +n/2 are outside the specified device range (error
S S
to +n-1 are outside the specified device range
D D
K6
END
b15
D20 00H
D21 00H
D22 00H
D23 00H
D24 00H
D25 00H
"00H" is stored.
19 Data Operation 2 – FNC140 to FNC149
19.2 FNC141 – WTOB / WORD to BYTE
S
b8 b7 b0
00H 39H
00H 12H
00H 78H
00H 56H
00H DCH
b8 b7 b0
00H 31H
00H 32H
00H 33H
00H 34H
00H 35H
b8 b7 b0
58H
FDH
E2H
57H
44H
34H
+2 is stored in
When "n"
is "5"
When "n"
is "5"
6 bytes