<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Ok thanks Tyler.<br></div><div><br data-mce-bogus="1"></div><div>I'll leave it up to you to pull the relevant people together when you are ready.<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Cheers<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Ruben<br data-mce-bogus="1"></div><div><br></div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"Tyler Lemon" <tlemon@jlab.org><br><b>To: </b>"dsg-hallb magnets" <dsg-hallb_magnets@jlab.org><br><b>Sent: </b>Monday, January 23, 2017 4:46:25 PM<br><b>Subject: </b>Re: [Dsg-hallb_magnets] Filtered Torus Fast-Daq data<br></div><div><br></div><div data-marker="__QUOTED_TEXT__"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div>Nick,<br></div><div>The filtering version has now been deployed.<br></div><br><div>Ruben,<br></div><div>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. </div><div>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.<br></div><br><div>Best regards,<br></div><div>Tyler<br></div><br><br><hr id="zwchr"><div><b>From: </b>"Ruben Fair" <rfair@jlab.org><br><b>To: </b>"Tyler Lemon" <tlemon@jlab.org><br><b>Cc: </b>"Probir Ghoshal" <ghoshal@jlab.org><br><b>Sent: </b>Monday, January 23, 2017 3:49:41 PM<br><b>Subject: </b>Re: [Dsg-hallb_magnets] Filtered Torus Fast-Daq data<br></div><br><div><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Tyler,</div><br><div>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?<br></div><br><div>Should we bring in anybody else to look at these results?<br></div><br><div>Can you set something up?<br></div><br><div>Regards<br></div><br><div>Ruben<br></div><br><br><hr id="zwchr"><div><b>From: </b>"Tyler Lemon" <tlemon@jlab.org><br><b>To: </b>"dsg-hallb magnets" <dsg-hallb_magnets@jlab.org><br><b>Sent: </b>Monday, January 23, 2017 2:59:06 PM<br><b>Subject: </b>[Dsg-hallb_magnets] Filtered Torus Fast-Daq data<br></div><br><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div>Hello Ruben and Probir,<br></div><br><div>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.<br></div><br><div>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. <br></div><br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000">Fast-Daq data was also recorded via EPICS during test with file names below:<br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000">file name time length filter applied<br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000">torus_20170123_141100.root 1 minute no filter<br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000">torus_20170123_142200.root 1 minute lowpass filter, cutoff frequency 50Hz<br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000">torus_20170123_142600.root 5 minutes lowpass filter, cutoff frequency 50Hz</div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><br></div>For now, the original Fast-Daq program without any filtering has been redeployed.</div><br><div>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.<br></div></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><br><div>Best regards,<br></div><div>Tyler</div></div></div></div></div></div><br></div></div><br>_______________________________________________<br>Dsg-hallb_magnets mailing list<br>Dsg-hallb_magnets@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/dsg-hallb_magnets</div></div></div></div><br></div></div><br>_______________________________________________<br>Dsg-hallb_magnets mailing list<br>Dsg-hallb_magnets@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/dsg-hallb_magnets<br></div></div></body></html>