This behavior i am experiencing is on the 2017/2018 Image:
I am running into an issue where no matter how I've created an IIO buffer to be transmitted the buffer is always repeatedly being transmitted as if it was in cyclic mode. The attached example sets-up a local IIO context and a TX buffer to transmit just once. The TX buffer is created using the IIO API
iio_device_create_buffer(tx, TRANSMIT_FRAMESIZE , false)
Despite just "one" transfer, opening up IIO-Oscilloscope reveals that this waveform is being repeatedly sent if you examine the receiver Channel1 I/Q (voltage0_i, voltage_q).
Terminating the C-application will destroy the Tx buffer and end the repeated transmission.