The Mapping Definition window shows the current mapping between attributes of adjacent input structures and output structures.
Right-click the connecting link, and select Mapping.
Display structure to view all attributes of the connected port and their current mappings.
Display structure and values to view the fields as well as the values of the current record. This view shows the current content of the port connecting to the link. If the port contains no data, only the port structure is shown in this window. You can populate data in a port by stepping through your project until you reach the port.