Siemens 353 - Ln - Natural Logarithm; Log - Logarithm Base 10

Function Blocks UM353-1B
April 2012
3-48
3.2.47 LN_ - NATURAL LOGARITHM
LN_ function blocks will output the natural logarithm of input X.
When the input is <= 0.0, the input will be treated as the smallest
number greater than 0.0 (i.e. 1.17....e-38) and the LN will be computed
accordingly.
BLOCK DIAGRAM
O1X
Input
X
O
utput
1
.
.
LNe (X)
3.2.48 LOG_ - LOGARITHM BASE 10
LOG__ function blocks will output the logarithm to the base 10
of input X. When the input is <= 0.0, the input will be treated as
the smallest number greater than 0.0 (i.e. 1.17....e-38) and the
LOG will be computed accordingly.
BLOCK DIAGRAM
O1X
Input
X
O
utput
1
.
.
LOG10 (X)
Input
X
LOGARITHM BASE 10
O1
O
utput
1
O
1
= LOG (X)
LOG
ESN =
000
X
E
E
xec.
S
eq.
N
o. ..................... 000 to 250 (000)
X
T
U
P
N
I
INPUT X
..............
loop tag.block tag.output (null)
SN
Input
X
NATURAL LOGARITHM
O1
O
utput
1
O
1
=LNe (X)
LN
ESN =
000
X
E
E
xec.
S
eq.
N
o. ..................... 000 to 250 (000)
X
T
U
P
N
I
INPUT X
..............
loop tag.block tag.output (null)
SN