I am trying to create reference for check from payment document. I ran FCHU targeting "Assignment" field. When I execute FCHU it shows the documents but when I go back to the document, the assignment field is not updated.
Any assitance is greatly appreciated.
Functionally for updating the PAYR table you need to execute the transaction code FCH5 to create the check information first. Once this is created the program in the background of transaction code FCHN updates the check number in the selected target filed (assignment field in your case).
Hope that helps you.