I don't have the plug and play RigBlaster, but came close to purchasing one so I read up on it a lot.
Anyway, with the Yaesu rigs, the data port and cat port are separate. You need to buy the cat cable that hooks up to the plug&Play and the radio before you can control it. The data cable will only key the rig and transfer sound back and forth too it.
I have the FT857D which is basically the same radio. http://www.westmountainradio.com/Image/StoreConfigs/catmini_cbl.htm
That is the cable you need, it is on the pricing page at west mountains site, and I have found it at HRO as well.