I added offsets to avoid zero crossings in the requested DAC outputs for the bottom stage of the SRC suspensions. I did this for SRM, SR2, and SR3 although SR3 isn't used. This didn't make any noticable difference in the DARM spectrum (see attached spectrum).
Georgia pointed out that there might have been a change in the glitches around the time that I did this, so I have turned them on and off a few times. Looking at the summary pages, it doesn't seem as though there is a repeatable difference in the glitches with the offsets on and off. Since these offsets are small (just large enough to avoid 0 crossings with a little headroom) they shouldn't impact acquisition. I have accepted them in SDF and will plan to leave them on unless there are problems.
SRC M3 offsets:
- on: 16:56:01 UTC August 4th 2022
- offsets off: 17:30:00 UTC
- offsets back on: 17:50 UTC
Tagging DetChar for input.
The distribution of certain Omicron parameters betweeen the offsets on and off periods look broadly similar (see attached), the number of counts seems approximately in line with the fact that the offsets off period is 80% the length of the offsets on period. I am making qscans of Omicron trigger clusters and will review the images in the morning to see if there's any interesting behavior. Barring anything strange in these, it looks like the new offsets are not introducing any strange glitching.
These offsets have been reverted after the SRM and SR2 M2 and M3 DACs have been upgraded from 18-bit to 20-bit DACs on Tuesday Aug 09 2022 -- see LHO:64381. Though they did not get upgraded, I also turned OFF the offsets one the M3 stage of SR3. Now all COIOUTF offsets installed in the above aLOG are OFF.