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 :

ST Statement: IF The IF statement is used for checking a condition and, depending on this condition, for executing the subsequent statements. A condition is coded as an expression that returns a Boole

ST Statement: FOR The FOR loop is used to execute statements with a certain number of repetitions. Syntax: FOR <counter> := <start value> TO <end value> {BY <increment> } DO <instructions> END_FOR; Th

ST Statement: CASE The CASE statement is a conditional control structure which causes a statement or a section of a statement to be executed only under a specific condition. The section which is execu

ST Statement: RETURN Use the RETURN statement in order to exit from a function block. You can make this dependent on a condition , for example. Example 64 . Example IF xIsDone THEN RETURN; END_IF; iCo

Keywords In all editors, you must capitalize keywords that for example denote scopes, data types, or operators. Keywords cannot be used as variable names. Example 282 . Example VAR END_VAR BOOL_TO_INT

Error Messages and Warnings :