L9E_LOGFP: Floating Point Common Logarithm
(Original Document)
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Naming
Name in LL984 Editor
Function Block Name
name of legacy 984 instruction
name in other tools and editors like:
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Function Description
The L9E_LOGFP DFB calculates the common logarithm of a floating point value and stores the result in an array.
Representation
Parameters
Input Pin
Name
Data Type
Address Range
Meaning
Top
ENABLE
BOOL
–
ON = calculates the common log of the value
Node
Node Type
Name
Data Type
Address Range
Meaning
Top
IN
VALUE1
ARRAY[1...2] OF UINT
%MW
value > 0 in floating point format
VALUE1 stores the value > 0 in floating point format.
If the value ≤ 0, an invalid result will be returned in RESULT and an event will be logged in the L9E_ERLOG DFB.
Middle
IN/OUT
RESULT
ARRAY[1...4] OF UINT
%MW
common logarithm of VALUE1
The common logarithm of VALUE1 is posted in floating point format in word 3 and 4.
Word 1 and 2 are not used but allocation is required.
Note: To preserve space, you can make the %MW reference numbers assigned to word 1 and 2 equal to VALUE1, since word 1 and 2 are not used.
Output Pin
Name
Data Type
Address Range
Meaning
Top
OUT
BOOL
–
ON = operation successful