SQZ Morning Troubles
After reading Tony's alog, I had the suspicion that this was the SHG power being too low, causing lock issues. I trended Sheila's SHG Power while adjusting the SHG temp to maximize. This worked to lock SQZ almost immediately - screenshot below.
However, despite SQZ locking, it looked like in trying to lock for hours the SQZ_ANG_ASC had gone awry and as the wiki put it, "ran away" I requested the reset SQZ_ANG guardian but this didn't work. Then, I saw another SQZ Angle reset guardian, called "Reset_SQZ_ANG_FDS", which immediately broke guardian. The node was in error and a bunch of settings in ZM4 abd ZM5 got changed. I reloaded the SQZ guardian and successfully got back to FREQ_DEP_SQZ. I saw there were some SDF changes that had occured so I undid them, successfully making guardian complain less and less. Then, there were 2 TCS SDF OFFSETs that were ZM4/5 M2 SAMS OFFSET and they were off by 100V, sitting at their max 200V. I recalled that when SQZ would drop out, it would notify something along the lines of "is this thing on?". I then made the assumption that because this slider was at its max, all I'd need to do was revert this change, whic happened over 3hrs ago. I did that and then we lost lock immediately.
What I think happened in order:
Now, I'm relocking, having reverted the M2 SAM OFFSETs that guardian made and having maximized the SHG Temp power (which interestingly had to go down contrary to yesterday). I've also attached as screenshot of the SDF change related to the AWC-SM4_M2_SAMS_OFFSET because I'm about to rever the change on the assumption it is erroneous.
What I find interesting is that lowering the SHG temp increases the SHG power first linearly, then after some arbitrary value, exponentially but only for one big and final jump (kind of like a temperature resonance if you can excuse my science fiction). You can see this in the SHG DC POWERMON trend that shows a huge final jump.
Recovered from Lockloss and got to OBSERVING automatically - 17:58 UTC.
Only SDF was the only change I made which was re-adjusting SHG temperature to maximize its power.
Investigating further, I realize that once I fixed the SHG temp issue, the message "SQZ ASC AS42 not on??" was the flashing notification, in which I should have followed: alog 71083. Instead, SDF led me to what the specific issue with ASC was. I will continue to monitor and investigate. Since range is fluctuating, I will probably go into comissioninbg to try and optimize squeezing once thermalized.
Ibrahim summarized this over the phone for me, and here's our summary of 4 things that need a fix or looking into (sometime):
In regards to Sheila's final bullet point above, the change to the PSAMS offsets happened as a result of Tony's misclick (alog82585) where he brought SQZ_MANAGER to 'SET_ZM_SLIDERS_IFO [52]' as reported by the Guardian log at that time:
I also show this interaction in the attached ndscope.