3 functions, Functions, The software model – Lenze DDS v2.0 User Manual
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Introduction to IEC 61131-3 programming
The software model
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DDS-IEC61131 EN 2.0
2.2.3
Functions
Unlike FBs, functions cannot buffer their internal values. Thus, they cannot use global variables,
access function blocks and declare directly addressable variables. All functions have in common
that they return the same output parameters if the input parameters are the same.
Overview: IEC 61131-3 standard functions
Type conversion functions
..._TO_...
Conversion between integers
BOOL_TO
BOOL
Þ Type X
TO_BOOL
Type X
Þ BOOL
TIME_TO / TIME_OF_DAY
TIME / TIME_OF_DAY
Þ Type X
DATE_TO / DT_TO
DATE / DATE_AND_TIME
Þ Type X
STRING_TO
STRING
Þ Type X
TRUNC
REAL
Þ INT
Numeric functions
ABS
Absolute value
SQRT
Square root
LN
Natural logarithm
LOG
Logarithm to the base 10
EXP
Exponential function
SIN
Sine calculation in rad
COS
Cosine calculation in rad
TAN
Tangent calculation in rad
ASIN
Arcus sine calculation in rad
ACOS
Arcus cosine calculation in rad
ATAN
Arcus tangent calculation in rad
EXPT
Exponentiation of one variable with another
STRING functions
LEN
Indicates the string length
LEFT
Shows a left initial string
RIGHT
Shows a right initial string
MID
Shows a part of a string
CONCAT
Concatenation (connection) of two strings
INSERT
Inserts a string at a certain position into another string
DELETE
Deletes a part of a string
REPLACE
Replaces a part of a string by another part
FIND
Finds a part of a string
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