How to synchronize the RF in and out?

[kylongmu]

I'm using a RF-out to produce a SAWU waveform, this is used to control a VCO to produce a LFCW signal.
And i need both the RF-in channels to capture the LFCW reflect signal synchronized.
So it's nessasary to set the ADC's triger based on the SAWU's falling edge, is there some way to synchronize the RF in and out channels?

[Nils Roos]

You can only trigger the oscilloscope on the start of the moment of enablement of the awg, not on the waveform that is being generated.