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19 SINGLE NUMBER VARIABLE FUNCTIONS
19.4 Calculating the Common Logarithm
19.4
Calculating the Common Logarithm
LOG(_E)
These functions output the operation result of the common logarithm (the logarithm whose base is 10) of an input value.
Setting data
■
Descriptions, types, and data types
Processing details
■
Operation processing
• These functions calculate the logarithm whose base is "10" of the REAL type data input to (s), and output from (d).
• These functions are expressed as follows when the input value is "A" and the output operation result is "B".
• A value input to (s) is the REAL type data value.
• Only a positive value can be set in (s). (The logarithm operation cannot be executed for a negative value).
• When the operation result is -0 or underflow occurs, the operation result is regarded as 0.
■
Operation result
1.
Function without EN/ENO
The following table lists the operation results.
2.
Function with EN/ENO
The following table lists the execution conditions and operation results.
*1 When FALSE is output from ENO, data output from (d) is undefined. In that case, modify a program so that the data output from (d) is
not used.
Ladder diagram, FBD/LD
Structured text
[Without EN/ENO]
[With EN/ENO]
[Without EN/ENO]
d:=LOG(s);
[With EN/ENO]
d:=LOG_E(EN,ENO,s);
Argument
Description
Type
Data type
EN
Execution condition (TRUE: Execution, FALSE: Stop)
Input variable
BOOL
s(IN)
Input
Input variable
REAL
ENO
Output condition (TRUE: Normal, FALSE: Abnormal)
Output variable
BOOL
d(LOG(_E))
Output
Output variable
REAL
B=log
10
A
Operation result
(d)
No operation error occurred
Operation output value
An operation error occurred
Indefinite value
Execution condition
Operation result
EN
ENO
(d)
TRUE (Executes operation)
TRUE (Operation error did not occur)
Operation output value
FALSE (Operation error occurred)
Indefinite value
FALSE (Stops operation)
FALSE
Indefinite value
s
d
EN
ENO
d
s
Summary of Contents for MELSEC iQ-F FX5
Page 1: ...MELSEC iQ F FX5 Programming Manual Instructions Standard Functions Function Blocks ...
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Page 1068: ...1066 29 COUNTER FUNCTION BLOCKS 29 4 Counter Function Block Operation error There is no error ...
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