PLC Programming

Appendix E: Operators and Library Modules Overview
Appendix E: Operators and Library Modules Overview
The table shown below shows an overview on the operators, which are available in CoDeSys resp. in the
libraries Standard.lib and Util.lib. You find there the notation for ST and IL. For IL also the supported
modificators are listed.
Take note that for the 'IL operator' column: Only the line in which the operator is used will be displayed. A
prerequisite is that the (first) required operand have been successfully loaded in the preceding line (e.g. LD in).
The 'Mod. IL' column shows the possible modifiers in IL:
C
N
N
The command is only executed if the result of the preceding expression is TRUE.
for JMPC, CALC, RETC: The command is only executed if the result of the preceding
expression is FALSE.
otherwise: negation of the operand (not of the accumulator)
( Operator enclosed in brackets: only after the closing bracket is reached will the operation
preceding the brackets be carried out.
Please obtain a detailed description of usage from the appropriate Appendices concerning IEC
operators integrated into CoDeSys resp. the libraries.
Operators in CoDeSys:
in ST in AWL Mod.
AWL
'
..
[ ]
Description
String delimiters (e.g. 'string1')
Size of Array range (e.g. ARRAY[0..3] OF INT)
: Delimiter between Operand and Type in a
declaration (e.g. var1 : INT;)
; Termination of instruction (e.g. a:=var1;)
^
Dereferenced Pointer (e.g. pointer1^)
LD var1 N Load value of var1 in buffer
:= ST var1 N Store actual result to var1
S boolvar
R boolvar
Set boolean operand boolvar exactly then to TRUE,
when the actual result is TRUE
Set boolean operand boolvar exactly then to FALSE,
when the actual result is TRUE
JMP label CN Jump to label
CAL prog1 CN Call program prog1
CAL inst1 CN Call function block instance inst1
(vx, vy,..) vx, vy CN Call function fctname and transmit variables vx, vy
RETURN RET CN Leave POU and go back to caller
CoDeSys V2.3 10-61