ST Editor The ST editor is a textual editor used for the implementation of code in Structured Text (ST) and Extended Structured Text (ExST). The line numbering is displayed on the left side of the edi

ST Editor in Online Mode In online mode, CODESYS  displays the variables and expressions in the ST editor ( Monitoring of Values ). The writing and forcing of variables and expressions as well as debu

ST Expressions An expression is a construct that returns a value following its evaluation. Expressions consist of operators and operands. In Extended Structured Text (ExST) , you can also use assignme

Assignments :

ST Assignment Operator Syntax: <operand> := <expression> This assignment operator executes the same function as the MOVE operator. :

ST Assignment Operator for Outputs The assignment operator => assigns the output of a function, a function block, or a method to a variable. The position on the right side of the operator can also be

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

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 :