PLC Programming

IEC Operators and additional norm extending functions
STRING_TO Conversions
Converting from the variable type STRING to a different type:
The operand from the STRING type variable must contain a value that is valid in the target variable
type, otherwise the result will be 0.
Examples in St:
b :=STRING_TO_BOOL('TRUE'); (* Result is TRUE *)
w :=STRING_TO_WORD('abc34'); (* Result is 0 *)
t :=STRING_TO_TIME('T#127ms'); (* Result is T#127ms *)
TRUNC
Converting from REAL to INT. The whole number portion of the value will be used.
When you perform a type conversion from a larger to a smaller type, you risk losing some information.
Examples in ST:
i:=TRUNC(1.9); (* Result is 1 *)
i:=TRUNC(-1.4); (* result is -1 *).
Example in IL:
LD 2.7
TRUNC
GE
%MW8
10.9 Numeric Operators...
ABS
Returns the absolute value of a number. ABS(-2) equals 2.
The following type combinations for input and output variables are possible:
IN
INT
REAL
BYTE
OUT
INT, REAL, WORD, DWORD, DINT
REAL
INT, REAL, BYTE, WORD, DWORD, DINT
WORD INT, REAL, WORD, DWORD, DINT
DWORD REAL, DWORD, DINT
SINT REAL
USINT
UINT
DINT
UDINT
REAL
INT, REAL, WORD, DWORD, DINT, UDINT, UINT
REAL, DWORD, DINT
REAL, DWORD, DINT, UDINT
CoDeSys V2.3 10-19