Common Logarithm Operation On Floating-Point Data (Single Precision) - Mitsubishi Electric MELSEC-Q/L Programming Manual

Common logarithm operation on floating-point data (single
precision)
LOG10(P)
High
Basic
Process
performance
• QnU(D)(H)CPU, QnUDE(H)CPU: the serial number (first five digits) is "10102" or later
• 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)
Setting Internal device
data
Bit

(S)
(D) 
*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).
(S)+1
Log
10
32-bit floating-point
real number
• 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 89
Precautions.
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.
Error Error details
code
4100 The value specified in (S) is negative.
The value specified in (S) is 0.
4140 The specified device value is not within the following range:
-126
 | Specified device value | <2
0, 2
The value of the specified device is -0, a subnormal number, NaN (not a
number), or .
4141 The operation result exceeds the following range.
(when an overflow occurs)
|Operation result| < 2
7 APPLICATION INSTRUCTIONS
642
7.12 Special Function Instructions
Ver.
Redundant
Universal LCPU
LOG10
LOG10P
R, ZR
Word


(S) (D)+1
32-bit floating-point
real number
128
128
Command
LOG10
Command
LOG10P
J\ U\G
Bit Word
 
 
(D)
Q00J/
Q00/
Q01



S D
S D
Zn Constant
E
*1
 
 
QnH QnPH QnPRH
  
  
  
Others


QnU LCPU
 
 
 