4DSP Support Forum

Public Access => General Discussion => Topic started by: lufang on April 01, 2014, 01:52 AM

Title: FMC Analyzer oscilloscope does not work (not show the waveform)
Post by: lufang on April 01, 2014, 01:52 AM
Hi,
We are trying to use FMC Analyzer on FMC110 and ML605 platform via Ethernet, the firmware we use is the bit-stream in "4dsp\Common\Firmware\Recovery078_ml605_fmc110" folder.


"Open Device" is success and the spectrum chart works, but nothing is shown in the chart when switches to oscilloscope type (the screen capture is uploaded for a attachment).

ADC inputs are floating and internal clock is used, and raw ADC data can be save to a file, it seems that it is a software bug.

We install/re-install the 4FM SDK for 2 versions (Installer Version 2.225.1 & 2.219.2), but it goes the same.



Would you please give me some advices for the problem?


Thanks,
lufang
Title: Re: FMC Analyzer oscilloscope does not work (not show the waveform)
Post by: tonyku on April 01, 2014, 11:28 AM

Ok, we will take a look.

A quick question - what type of signal are you sending?   If it's a sinewave does it cross 0?   The software uses a zero crossing detection to trigger the sampling to prevent jitter, so if it doesn't detect a zero crossing, nothing will be displayed.  The frequency plot won't show this because it simply does an FFT calculation.

If the ADC inputs are left floating, then nothing will be shown because there will be no zero crossings. 

The ADC samples though should show whether there is a zero crossing or not.


Title: Re: FMC Analyzer oscilloscope does not work (not show the waveform)
Post by: lufang on April 03, 2014, 10:33 PM

Waveform works when we connect the DAC output to the ADC input. It is the reason of zero crossing.

Thanks for your reply!
Title: Re: FMC Analyzer oscilloscope does not work (not show the waveform)
Post by: arnaudNL on April 04, 2014, 03:56 AM
This topic is being closed because the issue is considered as resolved by 4DSP. Feel free to create a new topic for any further inquiries.