goto ebay and search nissan consult
i just brought one for my 1994 bluebird SR20 based car, see if your car is in teh list
I got the serial rs232 one as im not using that for anything. and it make no difference to the data logging display VS USB.
you can only read the data with them, if you want to update your ecu as you drive sort of thing you need get it rchipped etc