PLC Programming

IEC Operators and additional norm extending functions
b := INT_TO_BOOL(0); (* Result is FALSE *)
b := TIME_TO_BOOL(T#5ms); (* Result is TRUE *)
b := STRING_TO_BOOL('TRUE'); (* Result is TRUE *)
Conversion between Integral Number Types
Conversion from an integral number type to another number type:
When you perform a type conversion from a larger to a smaller type, you risk losing some information.
If the number you are converting exceeds the range limit, the first bytes for the number will be ignored.
Example in ST:
si := INT_TO_SINT(4223); (* Result is 127 *)
If you save the integer 4223 (16#107f represented hexadecimally) as a SINT variable, it will appear as
127 (16#7f represented hexadecimally).
Example in IL:
LD 2
INT_TO_REAL
MUL 3.5
Example in FBD:
REAL_TO-/ LREAL_TO Conversions
Converting from the variable type REAL or LREAL to a different type:
The value will be rounded up or down to the nearest whole number and converted into the new
variable type. Exceptions to this are the variable types STRING, BOOL, REAL and LREAL.
Please regard at a conversion to type STRING that the total number of digits is limited to 16. If the
(L)REAL-number has more digits, then the sixteenth will be rounded. If the length of the STRING is
defined to short, it will be cut beginning from the right end.
When you perform a type conversion from a larger to a smaller type, you risk losing some information.
Example in ST:
i := REAL_TO_INT(1.5); (* Result is 2 *)
j := REAL_TO_INT(1.4); (* Result is 1 *)
i := REAL_TO_INT(-1.5); (* result is -2 *)
j := REAL_TO_INT(-1.4); (* result is -1 *)
Example in IL:
LD 2.7
REAL_TO_INT
GE
%MW8
Example in FBD:
CoDeSys V2.3 10-17