Introduction
Synchronization is a common requirement for a PXI system and RF systems are no exception. The problem is that NI TClk only natively supports synchronization of the NI 5673. In order to synchronize the generation of other Vector Signal Generators (VSGs) you have to separate the Upconverter and AWG sessions.
Steps to Complete

Additional Notes
This is a very simple example and does not allow for a great deal of difference between the generation of the multiple VSGs. Also, generation begins immediately after configuration is complete. Additional customization options could easily be added to the example letting different signals be generated from the AWGs or some sort of triggering.
Another important thing to note is that this example only synchronizes the generation of the signals from the AWGs, it does not make the VSGs phase coherent.
Regards,
Dan King
Example code from the Example Code Exchange in the NI Community is licensed with the MIT license.
Thanks! This helped alot!
So... You only need add property node with OSP mod "on" and set frequency at 25Mhz.