Справочник Пользователя для Mitsubishi Electronics MELSEC -Q/L
7 APPLICATION INSTRUCTIONS
7.12 Special Function Instructions
643
7
Common logarithm operation on floating-point data (single
precision)
precision)
LOG10(P)
*1 Available only for real number.
Processing details
• This instruction obtains the value specified by (S) for common logarithm (logarithm with base 10), and then stores the
operation result into the device specified by (D).
• Only positive values can be specified by (S). (Operation cannot be performed on negative numbers.)
• If the value resulted from the operation is -0 or an underflow occurs, the result will be processed as 0.
• When an input value is set using a programming tool, a rounding error may occur. For precautions, refer to Page 90
• If the value resulted from the operation is -0 or an underflow occurs, the result will be processed as 0.
• When an input value is set using a programming tool, a rounding error may occur. For precautions, refer to Page 90
Operation error
• In any of the following cases, an operation error occurs, the error flag (SM0) turns ON, and an error code is stored into SD0.
• QnU(D)(H)CPU, QnUDE(H)CPU: the serial number (first five digits) is "10102" or later
• Q00UJCPU, Q00UCPU, Q01UCPU, QnUDVCPU: Supported
• Q00UJCPU, Q00UCPU, Q01UCPU, QnUDVCPU: Supported
(S): Data of which the common logarithm is obtained or head number of the devices where the data are stored (real number)
(D): Head number of the devices where the operation result will be stored (real number)
(D): Head number of the devices where the operation result will be stored (real number)
Setting
data
data
Internal device
R, ZR
J\
U\G
Zn
Constant
E
E
Others
Bit
Word
Bit
Word
(S)
(D)
Error
code
code
Error details
Q00J/
Q00/
Q01
Q00/
Q01
QnH
QnPH
QnPRH QnU
LCPU
4100
The value specified in (S) is negative.
The value specified in (S) is 0.
The value specified in (S) is 0.
4140
The specified device value is not within the following range:
0, 2
0, 2
-126
| Specified device value | <2
128
The value specified in (S) is -0.
4141
The operation result is within the following range
(when an overflow occurs)
2
(when an overflow occurs)
2
128
| Operation result |
Basic
High
performance
Process
Redundant
Universal
LCPU
Ver.
LOG10P
LOG10
LOG10P
LOG10
S
D
S
D
Command
Command
Log
10
S
S
+1
32-bit floating-point
data type real number
32-bit floating-point
data type real number
D
D
+1