Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 481)

L-force | PLC Designer
IEC Operators and additional norm extending functions

DMS 3.2 EN 02/2011 TD29 479
9.6.2 LT
PLC Designer IEC operator: Less than
A Boolean operator that returns the value TRUE when the value of the first operand is
less 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
LT 30
ST Var1 (* Result is TRUE *)
Example in ST:
VAR1 := 20 < 30;
Example in FBD:
9.6.3 LE
PLC Designer IEC operator: Less than or equal to
A Boolean operator that returns the value TRUE when the value of the first operand is
less than or equal to 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
LE 30
ST Var1 (* Result is TRUE *)
Example in ST:
VAR1 := 20 <= 30;