Jeff,
The FP-20xx series modules do not support VISA. If you have a version of the Fluke 45 driver that uses the Serial VI's then they will work. However, the IVI driver does require VISA and thus will not work. I am afraid that you will most likely have to do some programming of a driver on your own. However, other than some additional programming effort, there should be no problem with reading from the Fluke 45 and publishing the data using the FP-20xx module.
Regards,
Aaron
LabVIEW Champion, CLA, CPI