PLC Programming

IEC Operators and additional norm extending functions
LIMIT 30,80
ST Var 1 (*Result is 80 *)
Example in ST:
Var1:=LIMIT(30,90,80); (* Result is 80 *);
MUX
Multiplexer
OUT := MUX(K, IN0,...,INn) means:
OUT := INK.
IN0, ...,INn and OUT can be any type of variable. K must be BYTE, WORD, DWORD, SINT, USINT,
INT, UINT, DINT or UDINT. MUX selects the Kth value from among a group of values.
Example in IL:
LD 0
MUX 30,40,50,60,70,80
ST Var 1 (*Result is 30 *)
Example in ST:
Var1:=MUX(0,30,40,50,60,70,80); (* Result is 30 *);
Note:
Note that an expression occurring ahead of an input other than INK will not be processed to save run
time ! Only in simulation mode all expressions will be executed.
10.5 Comparison Operators...
GT
Greater than
A Boolean operator which returns the value TRUE when the value of the first operand is greater than
that of the second. The operands can be BOOL, BYTE, WORD, DWORD, SINT, USINT, INT, UINT,
DINT, UDINT, REAL, LREAL, TIME, DATE, TIME_OF_DAY, DATE_AND_TIME and STRING.
Example in IL:
LD 20
GT 30
ST Var 1 (* Result is FALSE *)
Example in ST:
VAR1 := 20 > 30 > 40 > 50 > 60 > 70;
Example in FBD:
CoDeSys V2.3 10-11