Adalm Pluto transceiver design in Simulink

  • I am trying to test the DALM Pluto, configured as a simple transceiver. (tone in - tone out)

    In Simulink, I drop in the RX and TX Pluto modules and wire them up.

    I set up both modules with 2e6 sample rate, and both center frequencies 900MHz.

    I run the simulation.

    Then, using my signal generator, I send in a 900MHz tone into the RX port of the Pluto.

    I can see this tone on the virtual spectrum analyzer on Simulink, so all good so far.

    I then connect my real spectrum analyzer to the output port of the Pluto, as I want to see this tone appear here.

    Instead what I see is the tone, flicking on and off. It is not steady.

    Does anyone know why this is so?

    What can I not see the steady tone?