They all look the same, but they are not the same. The cable
required is a USB Type A Male to Mini B Male Cable. But, that is not enough of a
specification. I do not know how to tell them apart other than to try different
cables.

You must also install the Prolific USB driver first. It is found here:
http://flytec.com/software.html

After you have installed the driver, when you plug in the cable connected to the
6030 (turned off) your computer should "beep." If it doesn't that means you
haven't made connection.