The waiting structure returned by starting a transaction is dependent on the type of waiting requested. The progress of a transaction is found using usb_request_get_state(USB_RequestGetState (SWI&55390)) passing the transactions waiting structure (not the template!). Two values are returned the first is the usual result which indicates if the call was successful or not and the second shows the requests completion status (see Table A.3, “Request States”). For more details on waiting see Chapter 6, Waiting.