TJ, Josh, Andy, Joe

We used the ~18 hours of low noise data on October 12th to do a systematic check for DAC calibration glitches in the suspensions and found no clear evidence of any glitches due to calibration coupling into DARM. This check looks at crossings of 0 and +/- 2^16 for all SUS MASTER_OUT channels being sent to the DAC.

There were a few channels that showed zero or 2^16 crossings in coincidence with glitches in DARM, but these seem to be due to large glitches in the DARM loop driving the DAC output through 2^16 rather than the DAC output crossing through 2^16 and causing glitches.

We think some zero-crossings in PR3 might be coupling noticeably into PRCL, but we're still looking into this. The NOISEMON channel for PR3 M3 seems like it might be in need of a tune-up, it doesn't seem consistent with what we're seeing from other NOISEMONs.

A summary of our findings is stored at the following wiki: https://wiki.ligo.org/viewauth/DetChar/ER8DACglitchHveto