Form Data Update Tool is used to update the information in forms that have already been submitted. This is typically used for processing existing forms and updating fields based on business rules or data from external systems. Note that trying to use this tool for a form that has not yet been submitted will result in an exception. For pre-filling form fields of new forms, consider using either the Preset Form Data Tool, or you may use hash variables in your forms.
Figure 1: Form Data Update Tool Properties
Fields to be updated.
Which record row to update?
By default, it will try to look for record with the same id of the process instance it is currently in. However, you may also specify your own record id by explicating defining a "id" field and value.