Well, CVI is pretty easy for talking to instruments, but you will have to program. First thing is, get the GPIB card (if you haven't), then install it, and connect your instrument to it.
After that, go to http://www.ni.com/idnet. Go to Downloads and search for the instrument driver you need, in this case the 56400. Download that driver. There will be a DOC file that describes the instrument driver.
Next, go to CVI and from the Instrument menu go to Load... Find the instrument driver file (.fp) that you downloaded and load it into the menu. You will then have function panels for communicating to the instrument. If you need to learn CVI, we have a course that you can take, or you can buy the course manual and go through it yourself. Just go to htt
p://www.ni.com/custed/ to see our training options.
Best Regards,
Chris Matthews
National Instruments