Asynchronous calls: I am currently trying to execute a function module that writes data in a text file; therefore the function module doesn't have to have output parameters. This particular function module takes 3 minutes to execute because of the large amount of data it has to gather. When I use the GuiXT "call" command to execute the function module GuiXT waits for the function module to be completed and so the SAP GUI and all the screens that use GuiXT freeze until the function module is complete. Is there a GuiXT option that enables us to execute the call asynchronously?

GuiXT doesn't provide asynchronous calls but you can use the following solution: Write an additional function module F1 that calls up your time-consuming function F2 using an asynchronous ABAP call (e.g. Call... in Update Task, or create a batch job).