487
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
18 Floating Point – FNC110 to FNC139
18.13 FNC125 – LOGE / Floating Point Natural Logarithm
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
Program example
In the program example shown below, natural logarithm of "10" set in D50 is calculated, and stored to D30
and D31 when X000 turns ON.
X000
FNC 49
FLT
D50
Data used in the natural logarithm operation is set
([1]).
The data to be used is converted into binary floating
point (real number) ([2]).
The natural logarithm operation is executed ([3]).
D40
FNC 12
MOV
K10
D50
FNC125
DLOGE
D40
D30
END
Binary floating point
(real number) value
10
10
[1]
MOV
10
b15
b0
[2] Conversion into
binary floating point
(real number)
[3] Logarithm
operation
LOGE
D41
D40
Binary floating point
(real number) value
2.302585
D31
D30
FLT
D50
Binary value