Solution
Frequency modulation involves varying the frequency of a carrier in order to transmit a signal. RFmx Waveform Creator supports generation of an FM Mono, FM Stereo, and FM RDS signal. However, the software limits the modulation parameters. No matter the hardware or the FM signal of choice, the modulating frequency can be in the range of100 Hz to 15 KHz, and the frequency deviation can take a value between 1 Hz and 5 MHz. There is no way to remove this software limitation.
The only available workaround to overcome this is to use the LabVIEW Modulation Toolkit. When using this Toolkit to modulate an FM signal, there is no software limitation to the value the Deviation Frequency and the Modulating Frequency can take. Using this Toolkit, a user can create an FM waveform and then access the IQ data. This IQ data must be saved to a .txt file. Then, a user can access the IQ data in the .txt file using the niRFSG Write Arb Waveform (I-Q).vi from the API of the NI-RFSG driver. This NI-RFSG driver also ships with an example that shows how to do this, named RFSG Write Waveform From Text File.vi.