PLC Programming

APPENDIX
10 APPENDIX
Appendix A: IEC Operators and additional norm extending
functions
CoDeSys supports all IEC operators. In contrast with the standard functions functions (see appendix
D, Standard library), these operators are recognized implicitly throughout the project. Besides the IEC
operators CoDeSys also supports the following operators which are not prescribed by the
standard: INDEXOF and SIZEOF (see Arithmetic Operators), ADR and BITADR (see Adress
Operators).
Operators are used like functions in POU.
Attention: At operations with floating point variables the result depends on the currently used target system !
> Arithmetic operators
> Bitstring Operators
> Bit-Shift Operators
> Selection Operators
> Comparison Operators
> Address Operators
> Calling Operators
> Type Conversions
> Numeric Operators
10.1 Arithmetic Operators...
ADD
Addition of variables of the types: BYTE, WORD, DWORD, SINT, USINT, INT, UINT, DINT, UDINT,
REAL and LREAL.
Two TIME variables can also be added together resulting in another time
(e.g., t#45s + t#50s = t#1m35s)
Example in IL:
LD 7
ADD 2,4,7
ST Var 1
Example in ST:
var1 := 7+2+4+7;
Example in FBD:
CoDeSys V2.3 10-1