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 :

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

1 TO 5 BY 1 DO i

-3, label-4, label-5> : [...] . Example: 1 , 5 , c [...] : 1, 5 If one

Counter <> 0 DO Var1 :=

Counter-1; UNTIL iCounter = 0 END