X & Y green arms look good. But having issues getting to the next step. In the Troubleshooting document there is mention of adjusting the COMM Offset, but that made no change (as well as adjusting the DIFF Offset). I'm tempted to just run an alignment at this point, but I'm worried that won't address anything here since problem seems to be related to X-Arm for IR or PLL for ALS. I feel like I should be focusing more on them instead of alignment.
Below are notes and observations thus far:
FIND IR Notes:
- TR_X looks to be in la la land at around 0.3. (Should normally be around 0? Wondering if a dark offset is not correct.)
- (per troubleshooting guide) Adjusting ALS COMM first
- initial values: COMM @-200.0 & DIFF @-804.2
- Adjusting COMM did nothing.
- There is a DIAG_MAIN message for "waiting for DIFF PLL to come into range" (But I'm not seeing any issues for PLL related stuff for X & Y arms from the ALS Overview.)
- Delving deeper into sub-windows, do see some "redness" for the following in COMM PLL:
- ERRORs for COMM PLL related to Beat note*
- And further upstream see COMM VCO is sweeping the Tune Ofs slider until it reaches limits
- Delving deeper into sub-windows, do see some "redness" for the following in COMM PLL:
* In the Troubleshooting Wiki there is mention of zeroing the Crystal Freq if COMM has no Beatnote, but I'm not totally familiar with that.
At this point, I'm thinking I'm at a loss. I could atleast cross something off the list, by doing an alignment, so I will run an alignment (after I have some breakfast).
Running an alignment is a fine thing to do, especially after all those trips and reboots.
For the xarm IR transmission offset, you are correct that it should be around zero if the IFO is unlocked. Its offset gets changed every lock, so likely came back a little bit wrong after the boots since it is unmonitored in the safe.snap so the most recent value wasn't captured.
To fix the offset: LSC overview screen, far left about 2/3 the way down is a button "TR CARM". On the TR CARM screen, left side top there are a few filter banks. Change the offset of the XARM one to make the offset on the front wall TV be about zero. (There are 2 filter banks for x, and 2 for y. Should be the one with the smaller offset value. Try one of the XARM banks; changing the offset on the screen should make an immediate change to the trace on the wall. If it doesn't, revert and change the other one.)
Hopefully other find ir problems will be fixed by doing the alignment and adjusting this offset.
Thanks for the quick reply! I should have looked earlier, but I focused on dark offsets and then an initial alignment that took 2hrs! Ha.
But yeah, went ahead and addressed dark offsets, and then went for an initial alignment (alog on that about to be submitted!). Got stuck on INPUT_ALIGN (due to LSC-TR_X again). So I went through alogs and saw mention of an issue with ISIs for a Dec Dolphin crash. So I did what Jim mentioned for that case (request another state and then WINDY state), and this did the trick! Anyway, more thorough diary of Initial Alignment will be posted asap!