Hello Andreas,
I went looking through the National Instruments Instrument Driver Library, and was not able to find a LabVIEW driver for an HP 4339B. I did find one for an HP 4396A RF Network/Spectrum Analyzer. I am not sure what your instrument is, but the instrument drivers just use VISA to communicate with the instrument. If the VISA calls are similar between the 4339, and the 4396, then you may be able to use the 4396 driver.
What you need to do is use the manual for the 4339 to find out the communication strings, and the termination character that the instrument expects. These text strings can be added to an existing driver. However, I would only use a driver for a different instrument if: the two instruments do essentailly the same thing, and the commands to c
ommunicate with the instrument are "similar". In a perfect world, HP would make instruments that are controller with the same commands. This would make it unecessary to have 100's of different instrument driver for similar types of instruments.
If you find that the the instruments are not similar enough to make this method feasible, then you can request that National Instruments make a driver for you. Here is a link: http://zone.ni.com/idnet/, and from this page, you click on Other Driver Resources. Please keep in mind that National Instruments has finite resources devoted to writing 3rd party instrument drivers, and that not all requests can be honored.
