question about ad9361 tx 60M data


   I have used matlab to generate .mat file, which is of 60M sampling rate, 20MHz BW data. And I load it to our custom board with ad9361 on it, which has been transplanted the IIO Oscilloscope software. I load the .mat file to the iio oscilloscope, and set RF Bandwith to 20MHz, set sampling rate to 60MSPS. The output waveform is strange a s below:

  The .mat file itself is ok ,cause I have load it to zc706+fmcomms3, the output waveform is ok as below:

    We are using 1R1T, Dual Port Full Duplex DDR mode, with swap ports enabled. I read the UG-570, it says in this mode, maximum data date is 61.44MSPS(combined I and Q words). What reason could cause this situation?  Is my setting inappropriate for 60M sampling rate data to tx? Could you please give some advice?

   Thanks a lot. Looking forward to your reply.

[edited by: xiji at 9:20 AM (GMT 0) on 19 Jun 2019]