Oshino-san, Ikeda,

We continued the recovery work for K-Log #37511 yesterday. All digital systems have now been restored.

### k1boot power investigation

k1boot is connected to the PDU and UPS. [The original sentence about the UPS battery is incomplete.]
The UPS is connected to k1boot, k1cam0, k1cam1, and k1det0. Among the systems other than k1boot, k1com had an uptime of about 8 days and k1det about 201 days.
The UPS and k1boot are connected by USB, and k1boot was shut down by apcupsd. The reason the time is shown as 02:00 still needs investigation. There were no logs from the previous momentary power outage on August 27.

Sep 21 02:08:21 k1boot apcupsd[4298]: Power failure.
Sep 21 02:08:27 k1boot apcupsd[4298]: Running on UPS batteries.
Sep 21 02:08:58 k1boot apcupsd[4298]: Reached run time limit on batteries.
Sep 21 02:08:58 k1boot apcupsd[4298]: Initiating system shutdown!
Sep 21 02:08:58 k1boot apcupsd[4298]: User logins prohibited
Sep 21 16:06:44 k1boot apcupsd[4303]: apcupsd 3.14.10 (13 September 2011) gentoo startup succeeded
Sep 21 16:06:44 k1boot apcupsd[4303]: NIS server startup succeeded

### DGS

We restored all remaining FrontEnd PCs (FEPCs). All digital systems are now running.

After all models were started, IRIGB_TIME settled at values outside the acceptable range. We restarted the IOP models, which resolved the issue.

* K1IOO, K1PR2, K1EY0: settled at 27
* K1SR3, K1SRM: settled at 43

We also started k1bcst and k1nds3, which had been missed during yesterday’s recovery work.

### HWP

After a power outage, the rotary encoders lose track of their positions, so their home positions must be found again. We found the home positions for PSL and IFO_REFL and initialized them to 0 deg.
IMC remains uninitialized at Ushiba-san’s request. It can still be operated by treating its position after the power outage—the current position—as 0 deg.
After logging in to the HWP control PC, we ran the following commands to find the home position:

Rotater iSerial values are listed here:

The command exits when the rotator reaches its home position. During normal operation, “After status” changes from 1E (moving) to 32 (finished).

After that, when the rotator is moved from MEDM, “total” indicates the angle moved from the home position above. It is 0 deg immediately after initialization. There is no need to write an initial position from MEDM or elsewhere.

We changed the initial value for the AS HWP, as addressed in K-Log #37328:

> 1. A temporary value of 150 was set to prevent the division-by-zero error.
>    [medm] sitemap → SYS → HWP OVERVIEW → count2degree

We wrote 150 to `K1:SYS-HWP_IFO_AS_CT_PER_DEG_{P,N}` using `caput`.