[Dsg-hallb_magnets] Filtered Torus Fast-Daq data

[Ruben Fair]

Ok thanks Tyler. 

I'll leave it up to you to pull the relevant people together when you are ready. 

Cheers 

Ruben 



From: "Tyler Lemon" <tlemon at jlab.org> 
To: "dsg-hallb magnets" <dsg-hallb_magnets at jlab.org> 
Sent: Monday, January 23, 2017 4:46:25 PM 
Subject: Re: [Dsg-hallb_magnets] Filtered Torus Fast-Daq data 

Nick, 
The filtering version has now been deployed. 

Ruben, 
I would like to try changing the cutoff frequency to 45Hz and 40Hz. This should further attenuate any high frequency noise and also maybe stop the amplitude oscillations seen. 
After that, it would be good to have a meeting to discuss where to go from there in regards to what permanent changes should be made. 

Best regards, 
Tyler 



From: "Ruben Fair" <rfair at jlab.org> 
To: "Tyler Lemon" <tlemon at jlab.org> 
Cc: "Probir Ghoshal" <ghoshal at jlab.org> 
Sent: Monday, January 23, 2017 3:49:41 PM 
Subject: Re: [Dsg-hallb_magnets] Filtered Torus Fast-Daq data 

Tyler, 

Is it worth having a face-to-face discussion of these results before you do any more work - unless you already know what you would like to try next? 

Should we bring in anybody else to look at these results? 

Can you set something up? 

Regards 

Ruben 



From: "Tyler Lemon" <tlemon at jlab.org> 
To: "dsg-hallb magnets" <dsg-hallb_magnets at jlab.org> 
Sent: Monday, January 23, 2017 2:59:06 PM 
Subject: [Dsg-hallb_magnets] Filtered Torus Fast-Daq data 

Hello Ruben and Probir, 

A lowpass filter with cutoff frequency 50Hz was deployed to the Torus Fast-Daq cRIO. Attached are screenshots of the EPICS Live Fast-Daq screen from before and after the filter is applied. 

When the filter is applied, there appears to be an offset for scaled voltage taps. The offset seems to be about the signal average before the filter was applied (unfiltered average noted in attached "Unfiltered Voltage Tap Statistics 2017-01-23.JPG"). Some filtered signals also appear to oscillate in amplitude. Amplitude oscillations can be seen when comparing "01 Filtered Fast-Daq 2017-01-23.JPG" and "02 Filtered Fast-Daq 2017-01-23.JPG". The amplitude oscillations are probably due to frequency changes in the unfiltered noise, as the unfiltered signal's frequency determines the filtered signal's attenuation. 

Fast-Daq data was also recorded via EPICS during test with file names below: 
file name time length filter applied 
torus_20170123_141100.root 1 minute no filter 
torus_20170123_142200.root 1 minute lowpass filter, cutoff frequency 50Hz 
torus_20170123_142600.root 5 minutes lowpass filter, cutoff frequency 50Hz 

For now, the original Fast-Daq program without any filtering has been redeployed. 

If the filtered Fast-Daq program should be deployed for other tests or so anyone can see resulting signals for themselves, it can be done. 

Best regards, 
Tyler 


_______________________________________________ 
Dsg-hallb_magnets mailing list 
Dsg-hallb_magnets at jlab.org 
https://mailman.jlab.org/mailman/listinfo/dsg-hallb_magnets 


_______________________________________________ 
Dsg-hallb_magnets mailing list 
Dsg-hallb_magnets at jlab.org 
https://mailman.jlab.org/mailman/listinfo/dsg-hallb_magnets 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/dsg-hallb_magnets/attachments/20170123/c47309a6/attachment.html>