Insert Transition Objects

You can insert a transition object into the respective procedure sequence.

Transition objects control the processing of a procedure. Transition logic consists of an expression that is evaluated by the batch management system when the object is encountered. The result of an expression is Boolean. If the result is False, processing stops at the transition. If the result is True, the operations or phases following the transition are processed. You can use an unlimited number of transition objects in a procedure.

To insert a transition object (method 1)

1. On the Recipe Editor dialog box, select the Operation or Phase to which you want to add a transition

2. Click the Add Unit Procedure Transition, Add Operation Transition, or Add Phase Transition icon for the unit procedure, operation, or phase that you selected earlier.

   The transition is added to the procedure.

3. Double-click the transition object. The Transition Properties dialog box appears.

   

4. On the Transition tab, do the following:

   1. Type a Label (8  characters maximum).

   2. In the Name box, type a name for the transition (16 characters maximum).

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

   4. Click Change.

   When a transition is added, it is automatically assigned a unique Label (numeric value). The Name is initially the same as the Label. You can edit these as required. However, the Label must be unique. If it is not, a warning message appears.

5. On the Expression tab, click Expression.

   The Expression Editor dialog box appears.

   

6. Use the Expression Editor to construct transition expressions.

   You can build expressions using process and transfer instance tags, mathematical operators, and pre-defined functions. Several examples of valid expressions are shown in the following tables.

   For more information on building expressions, see Chapter 16, "Expression Editor".

7. Click OK and Close.

8. On the Transition Properties dialog box, click Close.

Transition Expression Examples

Notes:

• Transition Logic is a very powerful aid in developing a complete batch system. It is intended to be a useful tool in the coordination and processing of a recipe. It is not intended to extensively replace the functionality in the control system such as the PLC.

  Where you are performing Boolean expressions that are using tags in the system, there is inherent latency due to communications to the control system. Additionally, the associated processing overhead or demand placed on AVEVA Batch Management is nearly the same as that of a phase.

  In general, if you have in excess of 50 Boolean expressions that are using tags in the system, re-evaluate your system design and incorporate more control evaluation in the control system. The greater the number of transition objects in a system, the greater the demand that is placed on AVEVA Batch Management, which can result in decreased client updates and system responsiveness.

• When you enter questions, you are limited to 40 characters. The Expression Editor allows you to enter more than 40 characters. However, during processing, the entry is truncated so that only the first 40 characters appear.