Configure Formula Parameters for Automatic Process Phases

There are three types of formula parameters; input, output, and process variable. Process variable parameters are used to represent data such as set points and rates, input and output parameters are used when material tracking is required. Also, you must assign a specific data class type to each formula parameter. The available data class options are analog, discrete, string, and variable type parameters. Tag assignments to the elements associated with each parameter correspond to the assigned data class of the parameter. For example, only analog tags can be assigned to the elements of an analog process variable parameter.

Input parameters have seven elements. The parameter name defines a family of information while elements define the members of the family. The seven elements for input parameters are Target, Actual, High Deviation, Low Deviation, Preact, Lot Code, and Material ID.

Output parameters have three elements. The parameter name defines a family of information while elements define the members of the family. The three elements for output parameters are Target, Actual, and Material ID.

Process variables have six elements. The parameter name defines a family of information. Elements define the members of the family. The six elements for process variables are Target, Actual, High Deviation, Low Deviation, High Limit, and Low Limit.

The configuration of the parameter type, data class, and elements is extremely important. The AVEVA Batch Management System controls a phase and interacts with both the control system and the operator based on the configuration of the parameters.

The following sections contain a detailed explanation of the results that you can achieve for different parameter configurations.

Target Element

The target element is available for all parameter and data class combinations.

To configure the target element

• Select the Enable Display check box if the target value is to be shown during the run-time processing of the phase. If a tag is assigned to the element, the value assigned in the recipe is written to the control system by the AVEVA Batch Management System prior to the start of the phase. Typically, the phase logic uses the target value to determine when to end the phase.

• If the operator is allowed to modify the target, enable the Edit Allowed check box.

• If the operator must modify the target, enable the Edit Required check box.

• You can assign a Default Value to the target element for process variable parameters of any data class.

Configure the Actual Element

The Actual element is available for all parameter and data class combinations.

To configure the Actual element

• Select the Enable Display check box if the actual value is to be shown during the run-time processing of the phase. If a tag is assigned to the element, the AVEVA Batch Management System reads the value of the tag, in real time, from the control system during the processing of the phase.

• If the operator is allowed to modify the Actual value, enable the Edit Allowed check box.

• If the operator must modify the Actual value, enable the Edit Required check box.

Configure the High and Low Deviation Elements

High and Low Deviation elements are available for analog process variable parameters and analog input parameters and are expressed as a percentage of the target value. If tags are assigned, the AVEVA Batch Management System calculates and writes the deviation values to the control system prior to the start of the phase. Deviations are recalculated if changes are made to the target or deviation elements. For example, if the target value is 100, the high deviation is 3%, and the low deviation is 5%, the down-loaded high and low deviation values are 3 and 5, respectively.

To configure High and Low Deviation elements

1. Select the appropriate Enable Display check box if either of the element values are to be shown during the run-time processing of the phase. Typically, the phase logic uses the deviations to establish alarm limits or an acceptable phase completion range for the actual value of the parameter.

2. If the operator is allowed to modify either of the deviation values, enable the Edit Allowed check box.

3. If the operator must modify either of the deviation values, enable the Edit Required check box.

4. You can assign a Default Value to the high and low deviation elements for analog process variable parameters only.

Configure the High and Low Limit Elements

The high and low limit elements are available for analog process variable parameters and are used by the Recipe Editor and the AVEVA Batch Management System to prevent the entry of out-of-range values. If tags are assigned, the AVEVA Batch Management System writes the limit values to the control system before the start of the phase.

To configure High and Low Limit elements

5. If either of the element values are to be shown during the run-time processing of the phase, select the appropriate Enable Display check box.

6. You can assign a Default Value to the high and low limit elements.

Configure the Preact Element

The preact element is available for analog input parameters.

To configure the Preact element

7. If the Preact value is to be shown during the run-time processing of the phase, select the Enable Display check box.

8. If a tag is assigned to the element, the Preact value defined in the process model is written to the control system by the AVEVA Batch Management System prior to the start of the phase.

Configure the Lot Code Element

The lot code element is available for analog input parameters.

To configure the Lot Code element

9. If the Lot Code value is to be shown during the run-time processing of the phase, select the Enable Display check box.

10. If the operator is allowed to modify the Lot Code, enable the Edit Allowed check box.

11. If the operator must modify the Lot Code, enable the Edit Required check box.

12. If a tag is assigned to the element, the value assigned by the operator or the control system is to be written to the AVEVA Batch Management System during the processing of the phase.

Configure the Material ID Element

The Material ID element is available for analog input and output parameters.

To configure the Material ID element

13. If the Material ID value is to be shown during the run-time processing of the phase, select the Enable Display check box.

14. If the operator is allowed to modify the Material ID, enable the Edit Allowed check box.

15. If the operator must modify the Material ID, enable the Edit Required check box.

Formula parameter configurations for the automatic process phase examples given earlier are shown in the following table.