1. Start the FBEditor.
2. Create a new data type in the editor by double-clicking on the Array, Direct, Enumerated, Structured or Subrange element in the template folder of the Library Navigator panel.
   • These elements are marked with the icon.
3. Edit the data type's elements:
   • Edit the data type's common properties.
   • Edit additional subtype-specific properties:
     • You can edit elements of a Structured data type graphically in the same manner as input variables of a function block type.
     • You can edit the elements of other subtypes by using the subtype node (the last node on the Element Navigator tree):
       • Double-clicking on the subtype node will bring up a dialog for editing an Array, Direct, or Subrange subtype.
       • You can add, delete, edit and rearrange elements of an Enumerated subtype by using appropriate popup menus, double-click and Drag and Drop operations on the subtype node and its children.
4. When your editing is complete, save your work with the Save As... button.
   It is a good idea to save your work from time to time while editing, too!
5. Generate and compile a Java® source file with the Save As... button.
   • For Subrange data types, the Java code includes a limitValue() method, which can be used to ensure that the variable's value is limited to stay within the subrange after performing a math operation.
6. Since data types are not event-triggered elements like function blocks, they cannot be tested directly with the Run item of the popup menu for the root node of the Element Navigator. See Testing Data Types for test strategies for the various kinds of data types.