XStep Parameters

Use

You use XStep parameters to model your data for an XStep module. The XStep parameters describe the contents of the XStep module and are valid for one XStep module only. XStep parameters also form the interface between the different XStep modules of an XStep tree and allow data to be exchanged between them. XStep parameters are therefore used as placeholders for the contents of XSteps, whose values are determined at a later point in time, or can be changed during processing.

You can use XStep parameters in the following way:

  • As a Variable

    For certain contents, for example, material numbers or material descriptions, you can define XStep parameters, which you can later use as a variable within the same XStep tree. The following contains several examples of XStep parameters being used in this way:

    • To output individual parts of a long text:

      Because you can define valuation symbols for XStep parameters, it is possible to replace individual parts of a long text. You define, for example, the long text “Add &PARAM1& Kg of material &PARAM2& ” and set the XStep parameters PARAM1 and PARAM2 as placeholders for the quantity and the material.

    • To output default values for input fields

      See also: XStep: Suggested Values in Input Fields

    • As single variables in calculation and inspection formulas, for example, for the upper and lower limit values in an inspection formula

      See also: XStep Calculations

    • For assigning values to the XStep parameters of a function module in the case of dynamic function calls

      See also:

      XStep: Dynamic Function Calls

      XStep: Function Module Parameters

    • To output descriptions for input or output fields

      See also:

      XStep: Outputs

      XStep: Inputs

  • To Allow the Exchange of Data Between XSteps Within an XStep Tree

    To transfer data between XSteps in an XStep tree, you must define reference parameters. For example, an XStep parameter at an XStep, which is located lower in the hierarchy, can be assigned the value from a higher-level XStep.Or, the XStep parameter of a higher-level XStep can be assigned the same value as a subordinated XStep (see Input and Output Parameters ).

  • Parallel Processing of Standard XStep References

    You can create references to standard XSteps in the SXS repository from the master recipe or the process order. In the application, you can assign specific values to the XStep parameters at the SXS reference interface, to meet the requirements of the particular master recipe or process order.

    See also: SXS References and Parameterization

Features

The data exchange is only possible between XSteps within the same XStep tree. Every XStep within an XStep tree is independent of the others, in terms of their contents. As a result of this, it is possible to use identical parameter names in different XSteps within an XStep tree without conflict.

  • Define XStep parameters, which should facilitate the data exchange with other XSteps within the same XStep tree, as input, output, or exchange parameters. The system writes these parameters at the parameter interface of the XSteps.

  • You define XStep parameters, which are to be used within the same XStep or are to be transferred to the XStep located immediately below in the hierarchy, as local parameters.

Data can only be exchanged directly between a higher-level XStep and the subordinated XSteps immediately below it. If you want to transfer data between two XSteps that are located at the same level within the hierarchy, you must firstly transfer the parameter value to a local parameter of the higher-level XStep, which can then be read by an input parameter of the subordinated XStep (see diagram).

Parameter Interface and Data Flow between XSteps

Definition of XStep Parameters

You define an XStep parameter for the contents of every XStep. Content values can be specified or used at a later point in time. The XStep parameters are only valid for the XStep in which they were defined. That is, they are not valid for subordinated XSteps. If the values for this XStep parameter are used in a subordinated XStep, you must transfer them using references.

If you want to create XStep parameters for an XStep, double-click the XStep node and maintain the tab pages Parameters and Valuation.

Tab PageParameters

On the Parameters tab page, create the parameter names, a description, a category and a characteristic.

Category

For every XStep parameter, you must specify whether it should:

  • Be assigned a parameter value from the higher-level XStep (category Input )

  • Transfer its own value to an XStep parameter in the higher-level XStep (category Output )

  • Be used within the same XStep, or its value be transferred to the subordinated XStep (category Local )

Category Input

You define an XStep parameter with category Input, if you want to assign a value from a higher-level XStep to this XStep parameter.

In this example, the value of the XStep parameter E should be created in the PI sheet in the higher-level XStep 1 and be displayed again in the subordinated XStep 1a. The transfer of the value from E to the subordinated XStep 1a is done using the input parameter X, which is assigned values from the reference with local parameter E.

Value

Permitted Categories for Parameter References

Use in Process Instructions

You can assign values to input parameters in the following ways:

  • Automatically

  • With a fixed value

  • With a reference parameter

  • Not at all

Input parameters of a subordinated XStep can be referenced with the XStep parameters of a higher-level XStep, which are of the following categories:

  • Input

  • Local

Input parameters can output in the process instruction. To do this, define a process instruction of type Output -> Parameter Value .

Category Output   

You define an XStep parameter with category Output, if you want to transfer the value of this XStep parameter to the higher-level XStep, which is located directly above the XStep in the hierarchy.

In this example, the value of the XStep parameter X should be created in the PI sheet in the subordinated XStep and be displayed again in the higher-level XStep. The transfer of the value from X to the higher-level XStep is done using the output parameter X, which is assigned values from the reference with local parameter E.

Value

Permitted Categories for Parameter References

Use in Process Instructions

You can assign values to output parameters in the following ways:

  • With a reference parameter

  • Not at all

Output parameters of a subordinated XStep can be referenced with the XStep parameters of a higher-level XStep, which are of the following categories:

  • Output

  • Local

You can create output parameters in the process instruction. To do this, define a process instruction of type Input -> Parameter Value .

  • Exchange     

    This category is a combination of Input and Output. The XStep parameter should be assigned a value and this should then be transferred.

  • Local      

    You define an XStep parameter of category Local , if:

    • The value of an XStep parameter should be used as a variable within an XStep, for example, as a suggested value.

    • The value of the XStep parameter should be transferred to an input parameter in the subordinated XStep

    • The XStep parameter should be assigned values using the value of an output parameter in the subordinated XStep.

      Value

      Use in Process Instructions

      You can assign values to local parameters in the following ways:

      • Automatically

      • Fixed

      • Not at all

      You can use local parameters in the process instruction in the following ways:

      • As input, if the XStep parameter has not been assigned values

      • As output, if the XStep parameter has been assigned fixed values, or been assigned values automatically.

Characteristic

You must assign a characteristic to every XStep parameter. The characteristic only specifies the data type of the XStep parameter. It can therefore be used several times.

Caution Caution

Note, that some business characteristics (for example, PPPI_MATERIAL or PPPI_BATCH) contain suggested input values and input validation. In the PI sheet, input fields which have been assigned such characteristics as data type, can only be filled with a value which is appropriate in that particular business context.

End of the caution.
Tab PageValuation

On the Valuation tab page, enter a valuation type for each XStep parameter and create a value and valuation symbol if required.

Depending on the chosen category, you can value XStep parameters in the following way:

  • None

    The XStep parameter should either be used at a later point in the PI sheet, or not at all.

  • Automatically    

    The value of the XStep parameter should be determined automatically by the system on creation of the control recipe. You must specify a valuation symbol. The application context replaces the valuation symbols with specific values depending on the application context. The number of the header material in an order can, for example, be assigned automatically.

  • Fixed Value

    You define a fixed value to meet your requirements. In addition you can also define a valuation symbol. This is only appropriate, if you want to automatically assign a material description to the corresponding material in the PI sheet, for example.

  • Reference

    In this case, you assign the value of one XStep parameter to another XStep parameter. In doing so, you can only use a reference to XStep parameters that you have previously defined in the higher-level XStep. You specify an XStep parameter as a valuation from the higher-level XStep, whose value should be transferred to the current XStep parameter. When doing this, you must ensure that the categories of the two XStep parameters match. For example, an XStep parameter of category Input cannot be referenced with an XStep parameter of category Output (see category Permitted Categories for Parameter References )

    Note Note

    Note the following when working with reference parameters:

    The referenced XStep parameter must have been previously defined in the higher-level XStep.

    The characteristics of the XStep parameter in the higher-level and subordinated XStep must be the same.

    At the XStep tree node, you cannot assign values to the XStep parameter with valuation type Reference .

    End of the note.

    Permitted Valuation Types for Categories

Only certain valuation types are permitted depending upon which categories you have defined for an XStep parameter. The following diagram gives an overview of the permitted combinations.

Permitted Categories for Parameter References

If you have defined an XStep parameter, which is to be assigned values using a reference to a different XStep parameter, then the XStep parameter categories of the higher-level XStep and the subordinated XStep must match. The following diagram gives an overview of the permitted combinations.

Live Parameters

You use assign values using a live parameter, if you want to transfer data between two different PI sheets. In this case, you must set the Live Parameter indicator at the XStep parameter for both XSteps. The data exchange is done automatically using Manufacturing Data Access

Caution Caution

Note that parameters for tabular values cannot be defined as live parameters.

For further information on tabular values, see XStep Parameters for Tabular Values .

End of the caution.