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LOGD(P)
7.12.24 Natural logarithm operation on floating-point data
(Double precision) (LOGD(P))
LOGD(P)
Function
(1) Returns the natural logarithm of the value designated by taking (e) as base, and stores
operation results at device designated by .
(2) Only positive values can be designated by . (Operation cannot be performed on negative
numbers.)
(3) When the operation results in -0 or an underflow, the result is processed as 0.
Operation Error
(1) In any of the following cases, an operation error occurs, the error flag (SM0) turns ON, and
an error code is stored into SD0.
• The value designated by is negative. (Error code: 4100)
• The value designated by is 0. (Error code: 4100)
• The value of the specified device is not in the following range: (Error code: 4140)
0,2
-1022
| value of specified device | < 2
1024
• The value of the designated device is 0. (Error code: 4140)
• The result exceeds the following range (Operation results in an overflow):
2
1024
| Operation result | (Error code: 4141)
: Data of which the natural logarithm is obtained or head number of the devices where the data is stored
(real number)
: Head number of the devices where the operation result will be stored (real number)
Settiing
Data
Internal Devices
R, ZR
J\
U\G
Zn
Constants
E
Other
Bit Word Bit Word
–– –– ––
–– –– –– ––
Universal
Basic
Process
High
performance
Redundant
Command
Command
LOGDP
LOGD
LOGDP
LOGD
S D
S D
S
D
S
D
S
D
log
(
)(
)
64-bit floating-point
real number
64-bit floating-point
real number
+3
S
+2
S
S
+1
S
+3
D
+2
D
D
+1
D
S
S
S