You didn't say what kind of protocol converter, but assuming that you have something that converts DMX to a pixel protocol and pixels that use that protocol and everything is hooked up correctly and you are using the DMX firmware in the dongle, you just need to use something like vixen to program a sequence. You could also use the color picker or lynx deck to do simple testing.
The dongle by itself does not generate any test patterns. It just acts as an interface between the software you are using and the other hardware.
RM