No obvious cause but there was TCS CO2 steps happening at the time, and our funny LSC-DARM wiggle ~100ms before lockloss.
I looked at the quad L2 & L3 MASTER_OUT channels as well as the ETMX L2 NOISEMON and FASTIMON channels that you looked at for the 10/18 01:53UTC lockloss in 73552, and noticed a couple of things:
- this glitch was also seen by all of the other quad L2 MASTER_OUT channels as well as ASC-AS_A(attachment1)
- to me it seems very clear that the first channel to see this pre-lockloss glitch is ETMX_L3_MASTER_OUT(attachment2-zoomedin, attachment3-zoomedout)
Comparing this to the two recent locklosses that had pre-lockloss glitches, 10/15 08:53UTC and 10/18 01:53UTC(73552), both had not been caught by other quads or ASC-AS_A, and in regards to which channel had seen the glitch first, for the 10/15 LL I could not tell who saw it first (I had said that it had hit ETMX L3 first in 73552 but I think that was wrong), and for the 10/18 01:53 LL we previously discovered that either DARM or the DCPDs saw it first.
| LL | Time before LL (s) | Seen First By | Also Seen By |
|---|---|---|---|
| 10/15 08:53UTC | ~0.5 | either DARM, DCPDs, ETMX L3 | NOISEMON, FASTIMON, ETMX_L2 |
| 10/18 01:53UTC (73552) | ~0.17 | DARM or DCPDs | NOISEMON, FASTIMON, ETMX_L2 |
| 10/18 20:42UTC | ~0.1 | ETMX L3 | NOISEMON, FASTIMON, ETMX_L2, ITMs_L2, ETMY_L2, ASC-AS_A |
