Solution
Unfortunately, the RFmx Waveform Creator doesn’t support the use of triggers to begin signal generation.
However, there is an alternative using a LabVIEW example. Open LabVIEW, go to the Help menu, and select Find Examples… There, look for the example “RFsg Scripting with Triggers.vi”. This example will show you how to use triggers to control signal generation.
In the next picture, you can see a modification made to use one trigger to generate a specific signal (in this case the signal is generated programmatically but it could be imported from a File generated using the RFmx Waveform Generator)