Calculating The Common Logarithm Of Single-Precision Real Number - Mitsubishi Electric MELSEC iQ-F FX5 Programming Manual

Calculating the common logarithm of single-precision real
number
LOG10(P)/DLOG10(P)
These instructions calculate the common logarithm (the logarithm whose base is 10) of a value specified by (s), and store the
operation result in the device specified by (d).
The LOG10(P) instructions can also be used as DLOG10(P).
Ladder diagram
(s) (d)
FBD/LD
EN ENO
s d
Setting data
■Descriptions, ranges, and data types
Operand Description
(s) Data whose common logarithm is calculated or head device
number where the data is stored
(d) Head device number for storing the operation result
EN Execution condition
ENO Execution result
■Applicable devices
Operand Bit
X, Y, M, L, SM,
F, B, SB, S
(s) 

(d)
Processing details
• These instructions calculate the common logarithm (the logarithm whose base is 10) of a value specified by (s), and store
the operation result in the device specified by (d).
log ( (s)+1 (s) )
10
Single-precision real number
• Only a positive value can be set in (s). (The common logarithm operation cannot be executed for a negative value).
• The table below shows the related devices.
Device Name
SM700 Carry
SM8020 Zero
SM8021 Borrow
SM8022 Carry
Word
T, ST, C, D, W, U\G
SD, SW, R
 
 
(d)+1 (d)
Single-precision real number
Description
Condition
The absolute value of the operation result  2
The operation result is true "0".
(The mantissa part is "0").
The absolute value of the operation result < 2
The absolute value of the operation result  2
Structured text
ENO:=LOG10(EN,s,d);
ENO:=LOG10P(EN,s,d);
Range Data type
 Single-precision real number

Single-precision real number

Bit

Bit
Double word Indirect
specification
Z LC LZ
   
   
Operation
128
The value of (d) is the maximum value (2
numbers and the carry flag SM700 turns on.
The zero flag SM8020 turns on.
-126
The value of (d) is the minimum value (2
numbers and the borrow flag SM8021 turns on.
128
The value of (d) is the maximum value (2
numbers and the carry flag SM8022 turns on.
Data type (label)
ANYREAL_32
ANYREAL_32
BOOL
BOOL
Constant Others
K, H E $
   
   
128
) of 32-bit real
-126
) of 32-bit real
128
) of 32-bit real
8 APPLICATION INSTRUCTION
8.9 Real Number Instruction
8
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