Search found 211 matches

by hexamer
Sat Apr 13, 2019 2:19 pm
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Hello How can I build a signal sweep with the below characteristics: Frequency range: 100hz to 1khz Number of the cycle per frequency:5 Rest time between each frequency train:0.5 s Total number of frequency: 50 frequency in the range of 100hz to 1khz Thanks, Vahid Hello Vahid, Sorry for such a dela...
by hexamer
Tue Mar 19, 2019 12:56 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Hi Aaron, I just had an idea for a workaround against the AWG discontinuities: when you can manage to make the AWG oscillate for an exact multiple of full periods of the test frequency, the switch-off transient will be just the negative of the underlying switch-on transient. So all you would have t...
by hexamer
Mon Mar 11, 2019 2:39 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Thank you to Martyn for adding the attachments I was referring to in the prior post. The first is with 1 Hz bandwidth and the second with 0.1 Hz.
by hexamer
Mon Mar 11, 2019 2:32 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Result were indeed much better at the high frequencies, but now irregularities show up in the low frequencies. Hope this is logic for you Yes, this makes sense. When we set a fixed bandwidth, the application will try its best (within limitations of the scope's buffer size) to maintain that bandwidt...
by hexamer
Wed Mar 06, 2019 12:10 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

I thought, FRA4PicoScope is a personal private programming project of yours. So I am quite astonished to read that you'll "file an enhancement request on the Bitbucket project". It is a personal project, but I like to follow good development practice so I don't lose track of things. Please don't ta...
by hexamer
Tue Mar 05, 2019 11:44 pm
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Is the apparent contradiction possibly due to a misunderstanding when talking to the PicoTech applications engineer ? During sweep mode of the AWG apparently no reloading of the waveform table is necessary. Did you already think about this ? Firstly, I do believe the Picoscope is using DDS. The app...
by hexamer
Tue Mar 05, 2019 11:33 pm
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Will you be providing a new version of FRA4PicoScope improved with respect to this effect ? I'm not sure it will be worth enhancing adaptive stimulus mode any further. It's mainly for SMPS stability measurements, and the next planned enhancement for SMPS measurements will be a way to setup a multi-...
by hexamer
Tue Mar 05, 2019 5:35 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

@Aaron, can you make a screenshot of the settings you used? When I can get some more time I will :) Briefly though, on the plots I took with PS2204A, the cleanest one was done with all default settings, except for Extra Settling time, which I set to 1000 ms. In the meantime, if your curious, anothe...
by hexamer
Tue Mar 05, 2019 5:22 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

I think, now I understand, what you mean with AWG discontinuities and what the problem is. Your discontinuity comes from off- & on-switching of the stimulus. My advice is, don't do that, let it run at fixed amplitude and just change the frequency between measurement intervalls. I agree that this sh...
by hexamer
Tue Mar 05, 2019 5:07 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

could you give hints to literature about the "generalized Goertzel"-algorithm ? Here is the reference: Goertzel algorithm generalized to non-integer multiples of fundamental frequency Petr Sysel and Pavel Rajmic EURASIP Journal on Advances in Signal Processing 2012 2012:56. https://asp-eurasipjourn...
by hexamer
Sat Mar 02, 2019 10:54 pm
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

The FFT phase result is always depending on how much signal cycles fit into the time intervall. The phase error is zero, when an integer number fits exactly in. It is totally predictable, when non-integer numbers of cycles are in the intervall. But you can put this in different terms: it is possibl...
by hexamer
Thu Feb 28, 2019 1:44 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Kai, Your results are a bit perplexing. I would like to see if I can reproduce them. Your description should help. Here is what I can tell you for now: A primary reason for the extra settling time is that the Picoscope's AWG transition has discontinuities which can affect measurement. I'd be curious...
by hexamer
Tue Feb 26, 2019 11:36 pm
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Hi Hexamer, I solved the problem of returning the message log. I declared the P/Invoke to return and InPtr, and converted this InPtr using Marshal.PtrToStringUni(ptr) directly instead of calling Marshal.ReadIntPtr(pptr) first as I found in interop examples. Now it works perfectly, and I learned a b...
by hexamer
Thu Feb 14, 2019 4:22 am
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Full source code is available at: https://github.com/WimHuyghe/FRA-Impedance-Viewer Very nice work, Wim! I'll have to try this our soon. BTW, this is one of the kinds of application I had in mind when I made the API version of FRA4PicoScope. Had you considered integrating it that way? Should be pre...
by hexamer
Thu Jan 24, 2019 1:14 pm
Forum: Applications
Topic: Frequency Response Analyzer with Bode Plots
Replies: 420
Views: 166413

Re: Frequency Response Analyzer with Bode Plots

Hi, I'm having issues with the app after downloading and installing the latest .msi It worked before that, but after I installed it, I try to open the app and it thinks about it then fails to launch, no prompt as to why. Using a PS 5554B. Just want to confirm a few things to help you out: 1) I assu...