You might add a call to DXLSync after the execute request to ensure that
the execution has completed before you change the file name.
Using DX 4.3 under Linux 9.0 from the Python interface, I have no problem
reading any number of files. However, my files aren't changed quickly.
That's where the DXLSync might help.
You might also try something like
DXLSend( conn, "dxl_inputfile = \"/tmp/temp.dx\"; " )
instead of using DXLSetValue. I've had no trouble with the latter but know
the former works well.
Kent