Lenze PLC Designer PLC Designer (R3-1) - Manual (Page 1072)

L-force | PLC Designer
Programming Reference
1070 DMS 4.1 EN 03/2011 TD29
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Examples in IL:
(* Result is FALSE *)
(* Result is 29952 *)
(* Result is 129 *)
(* Result is 'DT#1998-02-13-14:20' *)
Examples in ST:
b :=DATE_TO_BOOL(D#1970-01-01); (* Result is FALSE *)
i :=DATE_TO_INT(D#1970-01-15); (* Result is 29952 *)
byt :=DT_TO_BYTE(DT#1970-01-15-05:05:05); (* Result is 129 *)
str:=DT_TO_STRING(DT#1998-02-13-14:20); (* Result is 'DT#1998-02-13-14:20' *)
Examples in FBD:
STRING_TO Conversions
IEC Operator: Converting from the variable type STRING to a different type.
The conversion works according to the standard C compilation mechanism: STRING to
INT and then INT to BYTE. The higher byte will be cut, thus only values of 0-255 result.
This way it is possible on most processors to generate optimal code because the
conversion can be performed by a single machine instruction.
Syntax for the conversion operator:
STRING_TO_<data 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.