Parallel recording of low and high frequency data

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Nepomukkk
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Joined: Thu Dec 05, 2019 6:40 pm

Parallel recording of low and high frequency data

Post by Nepomukkk »

With the picoscope 4824 I have to record oscillations from 0-100kHz over a channel, but with a second channel up to 5MHz (Both spectrum). So far I have not been able to do this over the settings. Do you have an idea how to do this?

Gerry
PICO STAFF
PICO STAFF
Posts: 1145
Joined: Mon Aug 11, 2014 11:14 am

Re: Parallel recording of low and high frequency data

Post by Gerry »

Hi Nepomukkk,

If you are in a Spectrum view then the bandwidth you set is for all channels, so you can't perform live Spectrum captures on 2 channels using different Bandwidths.

However, what you can do is use 2 different types of Spectrum views on data once it has been captured, as follows:
1/ Turn on channel B and connect your 2 inputs to both channels.
2/ Switch to Spectrum Mode (by clicking on the 'Spectrum Mode' icon) and set the bandwidth to 100kHz, and turn off channel A from being displayed in the spectrum plot (by going to 'Views->channels' and deselecting 'channel A').
3/ Switch back to 'Scope Mode', and perform a single capture
4/ Select a second view to automatically perform the spectrum plot (by going to 'Views->Add view->Spectrum') at 5MHz. (Setting the Timebase to a value of 10ms/div generates a sample rate of 10MHz, and the spectrum plot in the secondary view will always have a bandwidth equal to the Nyquist frequency of the Time Domain plot, i.e. in this case 5MHz.)
5/ Resize the spectrum view so that it is large enough and turn off channel B from being displayed in the spectrum plot (by going to 'Views->channels' and deselecting 'channel B').
6/ Once the capture is complete you can switch to Spectrum Mode again (to plot a Spectrum as a primary view) and you should now also have a 100kHz plot of the same data on Channel B.
7/ You can switch backwards and forwards between the display modes to show the channel A and channel B plots, or go to the Scope mode plot perform another capture and then switch between the channels again (if the data is changing when you switch channels then you may have remove the channel A input to stop it re-triggering when you switch view modes.)

I have attached 2 psdata files for the 2 different types of views (as PicoScope 6 will only save one type of view at a time) which have the channels setup as I described and shows the 2 different spectrum plots.

Secondary view Spectrum plot.psdata
(1.54 MiB) Downloaded 404 times
Primary view Spectrum plot.psdata
(88.6 KiB) Downloaded 406 times

Regards,

Gerry
Gerry
Technical Specialist

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