The LockLoss at 12:51:54 UTC was preceded by 4 seconds, by a Verbal Alarm for MC3, at 12:51:54 UTC.
Attached is a time series of the MC3 M1 OSEMS, and the H1:SUS-MC3_M1_OSEMINF_T2_OUT_DQ starts to glitch at 125.84 seconds into the plot, while the other MC3 M1 OSEMS, and Cal Delta and OMC DCPD A, are unaffected.
Other MC3 M1 OSEMS glitch next, then LockLoss.
Attachments:
- 1) 0 to 125 seconds into the plot, MC3 T2 has not glitched
- 2) 0 to 126 seconds, which includes LockLoss
- 3) 125 to 126 seconds into the plot, showing MC3 T2 glitches at 125.844 seconds into the plot, then the other MC3 OSEMS gltich, then LockLoss
While Relocking, DRMI lost lock and that also gave a Verbal Alarm for MC3.
Very interesting, good find Cheryl.
It's also in the drives, but only on MC3. So, it looks like it's something with the MC3 suspension, since if it was a glitch coming from the WFS it should show up on all of the IMC suspensions.
This happened to Sheila and me again this morning, as we were trying to finish up going to low noise at 40W, but this time it was MC1's T2 and T3. The WFS don't see anything until after the glitch, so this confirms my earlier suspicion that it is not coming from the WFS.
If MC1 and MC3 are served by the same coil driver box, it sounds a lot like it might be glitching on us.
The following units were power cycled during a lockloss:
SUS-C4 U41 S1001089 Coil Driver (MC1)
SUS-C4 U40 S1000242 Coil Driver (MC1/MC3)
SUS-C4 U39 S1001084 Coil Driver (MC3)
SUS-C4 U30 S1108081 AI
Attached are screenshots from both of these locklosses. The first screenshot shows all the top mass osem readbacks, in most of them the glitch show up slowly because it is going through the damping loops and the mechanical response of the suspension, but the glitch in T2 is much faster which indicates it is a problem with that sensor in both locklosses (MC3 T2 in Cheryl's low noise locklosses, MC1 T2 in th recent lockloss at 40W input power).
The AA (S1105215) chassis was power cycled yesterday afternoon after a lockloss.