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Math Channels Filters

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Math Channels Filters

Postby Robsan » Thu Aug 14, 2014 1:09 pm

I am currently running 6.10.2.2 and 6.9.14 with a 6404B interface. I can not get the Math Channels Filters to work properly. For example if I setup a HighPass(A,1000) to filter out 60Hz noise The filter does very little to suppress the 60Hz noise, about -6dB is all I get with a filter set to 1000Hz. I couldn't get the band reject filter to work properly either, there seems to be some resonance in the filters that adds gain to the 60Hz signal. What kind of filters are these and how can I achieve my objective?

Thank you,

Rob
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Re: Math Channels Filters

Postby Martyn » Wed Aug 20, 2014 8:55 am

Can you post a psdata file, File->SaveAs and save the current waveform only, so that we can take a look at your data and settings.
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Re: Math Channels Filters

Postby simonj72 » Thu Oct 08, 2015 4:43 pm

I have a similar problem as Robsan.

I have setup two different math channels one with bandpass and one with highpass filter.

BandPass(A,500000,1600000)
Highpass(A,500000)

The bandpass filter suppress a 4 MHz disturbance OK but suppresses a 10 kHz disturbance very little
The highpass filter suppress the 10 kHz disturbance a little maybe 6 dB.

I use PicoScope software 6.10.18.1052

The data I am analyzing was captured with a PicoScope 5444A
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Re: Math Channels Filters

Postby Martyn » Fri Oct 09, 2015 7:17 am

Can you post a data file, either here or send to support@picotech.com, we can then take a look and see what is happening.
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Re: Math Channels Filters

Postby simonj72 » Thu Oct 15, 2015 12:37 pm

Hi,

I just tried to attach the file but it does not seem to work. The file is quite big, 86 MB, so that might be the problem.

/John
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Re: Math Channels Filters

Postby Martyn » Mon Oct 19, 2015 9:55 am

Can you post the file on a file sharing site, and send the details to support@picotech.com ?

or reduce the file size by just saving one waveform, rather than all buffers.
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Re: Math Channels Filters

Postby Martyn » Thu Oct 22, 2015 2:03 pm

Thank you for the file, we will let you know what we find.
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Re: Math Channels Filters

Postby Hitesh » Wed Nov 04, 2015 10:54 am

Hi simonj72,

I have responded via the e-mail support ticket that you have with us.

Below is a modified version:

'When using the filtering or Maths Channel feature, the number of samples across the screen is limited to 5MS (when using the PicoScope 6.11 Beta software). If you are collecting less than this amount, please try increasing the number of samples.

Otherwise if you could please provide further information indicating where the problem is occurring (an annotated screenshot would be fine) I would be happy to investigate further.'

Regards,
Hitesh

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Re: Math Channels Filters

Postby simonj72 » Mon Nov 23, 2015 4:16 pm

Hi Hitesh,

I transferred the file a to Martyn a while ago, see post before your post. It was quite big so I had to use Onedrive.

It would be easier if you just get the file from Martyn and open the file?

Best Regards
John
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Re: Math Channels Filters

Postby Hitesh » Tue Nov 24, 2015 8:53 am

Hi John,

I sent you a response via e-mail but if you have not received it below is the main part of the message:

'When using the filtering or Maths Channel feature, the number of samples across the screen is limited to 5MS. If you are collecting less than this amount, please try increasing the number of samples.

Otherwise if you could please provide further information indicating where the problem is occurring (an annotated screenshot would be fine) I would be happy to investigate further.'

Regards,
Hitesh

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