Mimaki CG-50

Hi to everyone. I am very new to sign cutting and just purchased a used mimaki cg-50 cutter plotter. However, did not come with any software or discs. Only available program is SignGo that i tried to get working but with no luck.

i have downloaded latest driver off the mimaki site for this unit, somehow cannot make it communicate with my computer, it has a serial cable all is hooked up but getting error ERR 20 I/O.

What am i doing wrong? Using windows xp.

Thanks in advance.