I just took a look at the "driver" on NI's driver network and see your problem(s). Do you have any of the functions of the Spec An implemented at this point? If so all you need, from a LabVIEW side, are a couple of sub-vi's to build the needed strings. I haven't worked with this particular SA in a very long time, so I don't remember specifically, but basically you manually set it up to make the measurements and then look up the commands strings required to do that and write them out to the instrument in LV. On some HP instruments, the mneumonics (the sh<>ortened command) will be high lighted, or underlined, on the screen. The drivers shown on the NI web page, while requiring 6.x or 7.x to run, are old, as they aren't using VISA, make heavy use of sequence structures, etc. (and the copyright notice is from 1993! LabVIEW 2.5.x era!)
Let me know what version of LabVIEW you are using and how much or what driver(s) you already have. Also whether you have access to the instrument and hopefully its command set and we'll see where to go from there.
Certified LabVIEW Developer
Senior Test Engineer North Shore Technology, Inc.
Currently using LV 2012-LabVIEW 2018, RT8.5