Loop Controls

You can insert a loop control into a procedure sequence. Use loop controls to re-run unit procedures that are built inside the control. Any procedure controls, including other loops, can be placed inside a loop structure.

Insert controls within the loop by positioning the new controls over any sequence inside the loop control. The bottom portion of the loop control contains a transition control that you must define with the Expression Editor. The result of the evaluation of the expression determines whether the controls contained within the loop are re-run or not. If the expression is True, loop processing returns to the top of the loop. If the expression is False, processing proceeds below the loop.

To insert a Loop Control

1. Open the Recipe Template editor and navigate to the Procedure tab.

2. In the Procedure container, drag the Loop from the Flow Controls library to the sequence where you want to add the loop. The loop is added to the procedure.

   When a loop is inserted, it is automatically assigned a unique alias name that you can edit.

3. Click the lower portion (transition) of the loop control. The Transition Details slide-in window appears. You can specify the expression in this window.

4. In the Transition Details slide-in window, do the following:

   1. In the Alias box, type an alias name for the transition (31 characters maximum).

   2. In the Description box, optionally type a description of the transition (120 characters maximum).

5. In the Variable section, the list of valid variables is displayed. These variables are listed for the current selected Capabilities as per the selected Equipment in the Recipe Template.

6. In the Expression section, you can define the expression using the transition logic and variables. The expression is a single logic statement that is built using operands and operators and evaluates to a true/false condition at runtime. The operands can consist of Equipment Variables (defined in Equipment configuration and linked to I/O) or static values (ex. 35.8, true, “allocated”). The operators can be one of the following (AND, OR, NOT, ==, <>, >, <, *, /, +, -). For more information regarding the operators, see the Expression Operator topic.

   NOTE: When you drag a variable on to the expression control, the variable is inserted at the cursor position and the cursor position is maintained. A space may be added before and/or after the variable to maintain separation between it and anything adjacent to the cursor.

7. Click Apply and then click Close.

   NOTE: If you click the Close button without clicking the Apply button, a confirmation message "Do you want to disregard the changes and continue?" appears. Click Yes to continue or click No to save the changes.

Deleting a Loop Control

You can remove loop controls from a procedure sequence. When a loop control is dragged to the garbage can, the garbage can is highlighted and the dragged loop control is removed from the procedure container.

To delete a Loop Control

8. Open the Recipe Template editor and navigate to the Procedure tab.

9. In the Procedure container, drag the loop control that you want to delete from the sequence to the Garbage/Delete can. A confirmation message appears.

10. Click Yes.

Moving a Loop Control

You can also reorder loop controls in the procedure by moving them to some other location within the procedure container. You can move an existing loop control into a procedure sequence just by dragging (at the bottom left corner or at the top left corner) and dropping the loop control from one place to another.