AnsweredAssumed Answered

Digital Oscilloscope DAC Buffer Output Tx Playback files?

Question asked by AnhDat on Jan 26, 2015
Latest reply on Jan 28, 2015 by dpu

Is there further documentation for iio-oscilloscope beyond http://wiki.analog.com/resources/eval/user-guides/ad-fmcomms1-ebz/software/linux/applications/iio_scope?

 

I am trying to test my AD-FMCOMMS3-EBZ Tx outputs-

setup:

Tx1 Output through 16dBm of attenuation loops into RX2 input

I set RF and TX chains to 40 MHz BW, 61.44 MSPS, 2450 MHz LO

TX RF Port = A

RX RF Port = A Balanced

Tx1 Attenuation = 30 dB but I've gone less to like 10 dB

DAC Buffer Output  loaded qpsknofilt_30M

select all voltages for DAC channels

 

Questions:

* I assume DAC Channels - 0-1 are for TX1 output, 2-3 are for TX2 output?

* the DAC Buffer Output will take the signal (matlab, etc) file and load it into FPGA and then play that back through the DAC our the TX ports selected at the TX carrier/BW set in the Tranmit Chain, correct?

* the test files 30M, 20M, etc are the 30 Megabaud, 20 Megabaud, rates for the file being modulated correct?

* After confirming functionality with your test files, I can make my own .mat or .txt files in similar format to load up and playback for testing correct?

 

Issue:

I'm playing around and can't seem to get the correct QPSK, or qam16 files to appear correctly on the TX output at the frequencies I've tried... I have another test demodulator equipment I'm trying to pick up the waveforms on and can't seem to lock on anything.  I'm tranmitting these DAC Buffer test outputs incorrectly I suspect, how are they suppose to be setup?

 

THANKS!

see attached setup.

Outcomes