Cariboulite TX light does not illuminate when "Transmitting" via a SoapyAPI

[PeterQFR]

Hi
I'm transmitting a signal to a SoapyCustomSink that is connected to a SoapySDRserver that is handling traffic to a cariboulite.

When I transmit a signal, an offset to a carrier wave, the Cariboulite does not illuminate its TX light which it does when I run the cariboulite_util.

I have a minimal setup:

but with the sink setup as follows:

but when I start it no TX light illuminates and no RF signal is generated (measured by other SDR)

[londero-usp]

any progress? It appears that much of the path used to transmit using I/Q is unfinished. And the lack of progress is making me somewhat suspicious about the continuation of this project.