what is the difference between the Flushes and discards contents of the receive buffer with and without performing any I/O to the device.
Refer to the LabVIEW Help for this function for more information. You can access the help for this function by right-clicking it on the block diagram and selecting Help from the shortcut menu. or by the following link:
I would say there is no difference, but I'll gladly accept other people's solutions/suggestions.