How to display only a math channel

Having problems ? let us know the details here
Post Reply
johnbicht
User
User
Posts: 5
Joined: Wed Jul 18, 2018 5:20 pm

How to display only a math channel

Post by johnbicht »

I have a stopband filter to eliminate 120 Hz hum (am in the US). I can't figure out how to display only the filtered data and have it not be hidden by the raw data.

Martyn
Site Admin
Site Admin
Posts: 4491
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: How to display only a math channel

Post by Martyn »

Right click on the display, click on Channels, and hide the ones you don't wish to see.
Martyn
Technical Support Manager

johnbicht
User
User
Posts: 5
Joined: Wed Jul 18, 2018 5:20 pm

Re: How to display only a math channel

Post by johnbicht »

That seems to work only when acquisition has stopped. And I am uncertain that the filter is working. bandstop(a,110,130) and I still get 120 Hz hum. Set the upper and lower limits to -.1 and .1 volt, which is the setting for channel A.

Martyn
Site Admin
Site Admin
Posts: 4491
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: How to display only a math channel

Post by Martyn »

If you are in streaming mode, where the trace is drawn from the left of the screen as the data is collected, the filter will not be applied until the trace is stopped by the user or the trace reaches the right hand edge when the complete waveform has been collected.
Martyn
Technical Support Manager

johnbicht
User
User
Posts: 5
Joined: Wed Jul 18, 2018 5:20 pm

Re: How to display only a math channel

Post by johnbicht »

That is unfortunate.

But what about... And I am uncertain that the filter is working. bandstop(a,110,130) and I still get 120 Hz hum. Set the upper and lower limits to -.1 and .1 volt, which is the setting for channel A.

Martyn
Site Admin
Site Admin
Posts: 4491
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: How to display only a math channel

Post by Martyn »

Can you post a psdata file with some raw data that you need to clean up, we can then play around with the filters and see what we can do.
Martyn
Technical Support Manager

johnbicht
User
User
Posts: 5
Joined: Wed Jul 18, 2018 5:20 pm

Re: How to display only a math channel

Post by johnbicht »

20180618-0003.psdata
(19.84 KiB) Downloaded 469 times
This is an example.

johnbicht
User
User
Posts: 5
Joined: Wed Jul 18, 2018 5:20 pm

Re: How to display only a math channel

Post by johnbicht »

Any joy with cleaning up this file? I really need to figure this filtering out for a business presentation.

bennog
Advanced User
Advanced User
Posts: 206
Joined: Mon Nov 26, 2012 9:16 am
Location: Netherlands

Re: How to display only a math channel

Post by bennog »

What about below cleanup ?
Is this what you mean ?
2018-07-25_08-05-56.png
Benno

sbabic44
User
User
Posts: 3
Joined: Thu Nov 30, 2017 10:17 pm

Re: How to display only a math channel

Post by sbabic44 »

And version with 20 Hz filtering on CH1. You can clearly see 8Hz component and slower envelope...

I tried bandpass filter and it seems to me it is not sharp enough to do what you ask...
Attachments
20180725-0001.gif

Post Reply