Sheila and I were looking at one of the most recent ETMX glitch locklosses and found something interesting. About 150ms before this particular lockloss there is a glitch that saturates L3, which seems to be between a few hundred hz and 1khz. The glitch is big enough to propagate to L2 and L1 very quickly. The IFO rides out one glitch, but seems to lose lock during a similar glitch immediately after. There were also 4 other glitches that looked kind of similar during this lock, that didn't cause a lockloss. The open loop for the ESD is around 70 hz, so we think it might be possible to add some more low pass to reduce the drive on the ESD, and reduce the chance of saturating the dac. I'm looking at that.

While trying to understand the path to the dac on this SUS, Sheila and I had a hard time finding the custom screen for the parts added to the top of the ETMX sus model for the 32-bit (-ish?) DAC on that suspension. It lives on the WD tab on the sitemap, it's called DAC_TEST. Shown in the second image. There are calibration gains of 275.310 applied to top level filter banks on the output of the model, these filter screens can be opened by clicking on the rows of black OUT GAIN and OUT VAL epics readbacks on the bottom of the screen. I don't think clicking any of the 0|1 buttons in the middle of this screen is safe.