ExST Assignment: S= When the operand of the Set assignment switches to TRUE , then TRUE is assigned to the variable to the left of the operator. The variable is set. <variable name> S= <operand name>

ExST Assignment: R= When the operand of the Reset assignment switches to TRUE , then FALSE is assigned to the variable to the left of the operator. The variable is reset. <variable name> R= <operand n

ExST Assignment as An Expression In ExST , as an extension to the IEC 61131-3 standard, CODESYS permits the use of assignments as expressions. Example 57 . Examples int_var1 := int_var2 := int_var3 +

Assignment Operator: REF= The operator generates a reference (pointer) to a value. Syntax: <variable name> REF= <variable name> ; Example 58 . Example refA : REFERENCE TO DUT; B : DUT; C : DUT; A REF=

Statements :

Object-Oriented Programming CODESYS supports object-oriented programming with function blocks and makes the following functions and objects available for this purpose: Methods Interfaces Properties In

Extension of a Function Block General The extension of a function block is based on the concept of inheritance in object-oriented programming. A derived function block "extends" a base function block

For Custom Data Types in CODESYS V3 Libraries Identifier designation recommendation for Description Example DUTs in CODESYS V3 libraries The namespace replaces the need for the library prefix. Therefo

For POUs Identifier designation recommendation for Description Example Functions, function blocks, programs Library prefix followed by an underscore and a short, informative POU name Like for variable

For POUs in CODESYS V3 Libraries Identifier designation recommendation for Description Example POU The library prefix is omitted because the namespace replaces the function of the library prefix. FUNC