Data Items

Data items are data bound to data sources that are external to the current workflow. If the data item has a defined data type, then the data item acts as a local variable of that data type.

For example, you can create a data item bound to the value of an iFIX tag. Each time the data item is accessed, the current value of the iFIX tag is returned. You can use this data item in an expression to determine a branching condition, which uses external data to drive execution of the workflow.
Note: You can configure up to 50 data items for each workflow definition.

Parameterized Data Items

A parameterized data item allows you to select a template data source (a preconfigured resource) both at the workflow level and at the subprocess level. A parameterized data item is different because you can select a different data source at run time. You can use parameterized data items when you configure schedules, run a test workflow, or invoke a Start Workflow activity.

You can specify the run-time data source data items in both Workflow Schedules and in the Workflow Editor Test tab. The data item configured in the workflow is used as a template to validate that the one chosen in the schedule is the correct data type.

In order for a parameterized data item to be effective, a run-time data source must be in a workflow. The parameterized data item on a subprocess cannot be directly linked to a data source; it must be bound to a workflow data item. This also means that it cannot be bound to a parameterized data item defined on another subprocess. If the parameterized data items are either unbound or are bound to an incompatible workflow data item, your workflow will not be valid.

Binding Data Items

Data items can be used directly in activity binds and expressions; that is, you can bind activity properties to a data source through a data item when the data item has a defined type. They can also be used as the target or source of a Write activity. For specific activities such as Read Data Items or Write Data Items, data items can be used as the target of these activities.

Data items are also used indirectly. For example, when you use multiple columns of data, or when advanced configuration of the read or write is required, you must use a Read Data Items or Write Data Items activity to access the data item.

Data items can also be used in Create Event activity expressions by binding an event variable to a data item. For more information, see Conditional Events.

Data Item Attributes

Note: Values displayed in the activity configuration panel are the default values of the selected data item. If you change the values in this configuration panel when configuring an activity, then these new values will be used.

The following table describes the available options.

AttributeValueDescription
ListN/ADisplays the items created for the current workflow or subprocess.
AddN/AClick to add.
RemoveN/AClick to delete the selection.
NameUser-definedSpecifies a display name for the selected property.
Data SourceSystem-definedClick the ellipsis button to open the Configure Data Source dialog box to select the specific data source you want this data item to bind to.
Make this data item a parameterSystem-definedSelect this check box, to configure the data source in Workflow Schedules and the Workflow Editor Test tab.
TypeSystem-definedDisplays the data type of the selected data source.
ReadableSystem-definedIndicates that the data source property can be read. This information displays after you have added a data source.
WriteableSystem-definedIndicates that the data source property can be written to. This information displays after you have added a data source.
Valid Event VariableSystem-definedIndicates that the data item can be used as an event variable. This information displays after you have added a data source. For more information, see Condition Event ExpressionVariables.
DescriptionUser-definedProvides more information that a user may find helpful.