PicoScope 7 Software
Available on Windows, Mac and Linux
Pico 2204A: Only 4096 bins on spectrum mode
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Hansebenger
- Newbie
- Posts: 1
- Joined: Sat Oct 17, 2020 9:36 am
Pico 2204A: Only 4096 bins on spectrum mode
Hi,
I use Pico 2204A on spectrum mode. While I can change the bins to more than 4096 in the spectrum options I think that it doesn't has any effect:
Spectrum doesn't seem to get finer when zooming in
CSV Export is always limited to 4096 bins
I have tried a lot of things to export more than 4096 bins in CSV until I stopped at thinking it's because of the model 2204A.
Am I right?
Which model has more bins?
Where does this limitation appear in the documentation?
I use Pico 2204A on spectrum mode. While I can change the bins to more than 4096 in the spectrum options I think that it doesn't has any effect:
Spectrum doesn't seem to get finer when zooming in
CSV Export is always limited to 4096 bins
I have tried a lot of things to export more than 4096 bins in CSV until I stopped at thinking it's because of the model 2204A.
Am I right?
Which model has more bins?
Where does this limitation appear in the documentation?
Re: Pico 2204A: Only 4096 bins on spectrum mode
Hi Hansebenger,
The number of Spectrum bins correlate approximately to half the number of samples used in the calculation of the FFT, which is half the number of samples that can be stored in the Buffer Memory of the Hardware PicoScope. In our Specifications, under Spectrum Analyzer, we state that the 'Number of FFT points' is "Selectable from 128 to half available buffer memory in powers of 2, up to a maximum of 1 048 576 points". As the 2204A only has a 8k Buffer Memory the maximum number of points or bins are 4096.
Even though the specifications are correct, I can see where they could be misunderstood, so I will submit a request to make this specification clearer.
Regards,
Gerry
The number of Spectrum bins correlate approximately to half the number of samples used in the calculation of the FFT, which is half the number of samples that can be stored in the Buffer Memory of the Hardware PicoScope. In our Specifications, under Spectrum Analyzer, we state that the 'Number of FFT points' is "Selectable from 128 to half available buffer memory in powers of 2, up to a maximum of 1 048 576 points". As the 2204A only has a 8k Buffer Memory the maximum number of points or bins are 4096.
Even though the specifications are correct, I can see where they could be misunderstood, so I will submit a request to make this specification clearer.
Regards,
Gerry
Gerry
Technical Specialist
Technical Specialist
Re: Pico 2204A: Only 4096 bins on spectrum mode
Hi Hansebenger,
Following on from my previous comment, If you are viewing lower bandwidth signals then there is a method that you can use to increase the bin count significantly. If you use Scope Mode to select a Timebase of 100ms/div, and then open a Secondary View in Spectrum Mode (Views->Add View->Spectrum) you will be streaming the data to the computer, and the FFT can use more data points to plot the Spectrum giving you up to 524288 bins. If you use Timebases slower than 100ms/div and then make sure that the 'Number of samples' requested is 3MS or greater, you will be able to plot up to the maximum of 1048576 bins (as shown below).
Regards,
Gerry
Following on from my previous comment, If you are viewing lower bandwidth signals then there is a method that you can use to increase the bin count significantly. If you use Scope Mode to select a Timebase of 100ms/div, and then open a Secondary View in Spectrum Mode (Views->Add View->Spectrum) you will be streaming the data to the computer, and the FFT can use more data points to plot the Spectrum giving you up to 524288 bins. If you use Timebases slower than 100ms/div and then make sure that the 'Number of samples' requested is 3MS or greater, you will be able to plot up to the maximum of 1048576 bins (as shown below).
Regards,
Gerry
Gerry
Technical Specialist
Technical Specialist
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Hansebenger
- Newbie
- Posts: 1
- Joined: Sat Oct 17, 2020 9:36 am
Re: Pico 2204A: Only 4096 bins on spectrum mode
Thanks for this clear answer!
This means that by upgrading to a bigger model I don't lose resolution. Great message for us all!
This means that by upgrading to a bigger model I don't lose resolution. Great message for us all!