Attached is a plot of the round trip delay times of EPICS PULL (active read) EPICS PUSH (active write) and EPICS PUSH/PULL (active write to 3rd channel, followed by active read from that channel).

PUSH and PUSH/PULL are dominated by a 2Hz update cycle. PULL sees a 8Hz update cycle.

The minimum delay for PUSH is around 110msec, for PULL and PUSH/PULL it is about twice that.

The delay for all three channels is about 10x too slow to be really useful (i.e. for acknowledgment returns shorter than the blink of an eye.)

Log from last Friday, 1 Nov 2013.  Took a look at the ITMx after setting up the Brunson optical square from the End-X station.  Position errors and pitch/yaw as of 1 Nov 2013 are:

• Longitudinal: -6.2 mm (South)
  • Tolerance: ±3.0 mm
• Lateral: -0.1 mm (East)
  • Tolerance: ±1.0 mm
• Vertical: -3.6 mm (low)
  • Tolerance: ±1.0 mm
• Pitch: -1007 µrad (down)
  • Target: 971 µrad
  • Error: -36 µrad (down)
  • Tolerance: ±50 µrad
• Yaw: +274 µrad (CCW)
  • Target: 0 µrad
  • Error: +274 µrad
  • Tolerance: ±50 µrad

I took down the IAS equipment Friday afternoon to allow for this morning's cryopump baffle installation.  While that is happening SUS and SEI are making alignment adjustments.  When the cryopump baffle installation is completed I will set the IAS equipment up again and measure the results of the moves.

Betsy, Travis

On Friday, we rebalanced the SRM suspension adding enough weight to the middle mass to bring it down such that the 2 AOSEMs which were maxed out in Z-position could be aligned.  These AOSEM brackets were poorly designed and we have found that many of the HSTSes at LHO (and likely at LLO, but awaiting their response) are built with the brackets at a range extreme.  So, while the SRM passed TFs the other week, we had to start over with balancing in order to bring these AOSEMs into alignment with a little bit of range adjustment.  Previously, the SRM had been balanced to within tolerance at ~0.75mm high.  Friday, we added enough weight to bring it to ~0.25mm low in order to bring the middle mass down a bit.  Note none of the other 12 OSEMs were out of range, just the 2 top ones on the middle mass.  Because of the rebalancing, Phase 2b TFs need to be run and evaluated again.

Maybe not necessary but caution is OK.  I locked the HEPI before ACB is swung back and SUS moves in to push the suspension around.

^* Level1 locked is just using the outer vertical & four outer horizontal lock bolts.  The others are extemely difficult to access and for the entire platform, overkill.

Alexa, Keita, Stefan and Sheila-

We have the last optic mounted and balanced in a tip tilt (SN 33) for HAM 6 (OM3).  We had difficulty balancing this the optic in this tip tilt,  even with a short bolt, 2 nuts and a washer on the back side we could not balance it.  Keita brought out SN20 and 25 which are intended for India (and do not have cables attached).  We had a similar problem balancing one of these.  Keita then noticed that there is slop in the four scews that attach the piece that clamps the wire to the rest of the mirror holder (picture attached, these are the 2 bolts on top and the 2 bolts on the bottom of the photo.) The tip tilts we were able to balance had those screws centered in their holes while they were off center in the tip tilts we were unable to balance.  We centered them on the india tip tilt and then we were able to balance it using a dummy optic.  We then did the same thing on the TT that was originally intended to be the H1 spare (SN33).

In the process we used a dummy optic from iLIGO that has a scratch in the center to avoid chipping more real optics.  

We took parts from TT SN9:  the peak nudge  (which was missing from SN33), the small screw that tightens the balancing bolt (we dropped this) and one of the OSEM flags (one flag on SN33 was bent).  

In the end, we have not changed anything for the india tip tilts (SN 20 and 25) except correcting the position of the small bolts, we have 3 balanced and ready for HAM6 (SN2,4, and 33) and one H1 spare (SN9) which is missing parts and needs the wires reclamped.  

On monday I will double check all of the serial nubers written in this alog to make sure they are right.  

Chris S. Joe D. Greg G.

With the help of Joe and Chris the SM1 mirrors (SN 3,4) were cleaned and are air-baking now, they should be done Monday evening. The SM2 mirrors were also completed recently and are wrapped and bagged and ready for install.

(Stefan Ballmer - not Jeff)

I set up a test for diagnosing front end to front end communications via 4 separate routes:
1) IPC
2) EPICS read (pull data)
3) EPICS write (push data)
4) EPICS write and read, via a third epics server (push to 3rd server, pull from 3rd server)

The setup has a counter on H1odcmaster, this is sent via temporary IPC to h1ascimc, and then returned back to h1odcmaster via the 4 routes described above. For IPC and epics read operations I get an error flag, which I am reporting. No such thing is available for an epics write operation.

h1odcmaster is currently running at 32k, h1ascimc is running at 2k.

I calculated the following quantities
- DELAY          : round trip delay in sec
- DELAY mean     : averaged DELAY
- DELAY max:     : largest DELAY observed
- JITTER MAX     : largest time interval between updates
- JITTER MIN     : shortest time interval between updates
- JITTER MAX-MIN : = JITTER MAX - JITTER MIN, the peak-to-peak jitter
- JITTER RMS     : root-mean-square of the time interval between updates

Conclusion for now:
- No errors observed in the ~1h this was running
- No jitter on IPCs
- epics read has a faster update rate (~8Hz) than epics write (~2Hz)
- as a result the delay is shorter for epics read
- the jitter MAX-MIN is about 40msec for EPICS access - the RMS jitter is about 4msec

I turned on recording for all the fast return channels over the weekend.

The modifications to h1ascimc and h1odcmaster will be backed out on Monday.

The ref cav was not locked all day, I didn't get a chance to look at it until just now, but it seems like the problem is actually with the PMC. 

The indicators on the medm screen seem to think that the PMC is locked, but it does not look locked in the camera, and the reflected power is 12.5 W. 

TF's running on ETMX ISI. More reps, so this test will take longer. Running on opsws6.

Sometime yesterday one of the leads for the DC power cable between a lab power supply and the Comtrol at end Y got disconnected. Richard went out and fixed it. I restarted the IOC for the attached dust monitor at 13:37. I later burtrestored it.

Roofers on the roof!
Removal of east and west doors from Ham 3 – Apollo
Checking dust monitors in LVEA – Richard
Dust monitor (unit #10) installed by HAM 3 – Richard
Baffle work in LVEA (West bay) – Mitchel/Thomas Vo
Working at End Y – Alexa
WBSC9 ETMx Alignment - Jason
Cable work from HAM3 to HAM6 – Filiberto
Delivery for Richard – PLATT Electric Supply
Vented sleeve surrounding GV6's gate annulus piping leak - Kyle

Took a look at the ETMx this morning to asses the alignment after the HEPI actuator install was completed.  As a reminder the large X axis positional error has been signed off by SYS, no correction will be performed.

• X axis Position: 3,999,485.0 mm
  • Target: 3,999,498.0 mm
  • Error: -13.0 mm
  • Tolerance: ±3.0 mm
• Y axis Position: -200.34 mm
  • Target: -200.0 mm
  • Error: -0.34 mm
  • Tolerance: ±1.0 mm
• Z axis Position: -79.8 mm
  • Target: -80.0 mm
  • Error: +0.02 mm
  • Tolerance: ±1.0 mm
• Pitch: -608 µrad (down)
  • Target: -360 µrad (down) -- [8 µrad ETMx pitch + 352 µrad FC correction]
  • Error: -248 µrad (down)
  • Tolerance: ±50 µrad
• Yaw: -30 µrad (CW)
  • Target: 0 µrad
  • Error: -30 µrad (CW)
  • Tolerance: ±50 µrad

IAS is now moving full time to the ITMx in WBSC3.  We will have to return to the ETMx to fine align the optic pitch and align the ETMx ACB.

This morning, I locked the BSC3 ISI and Greg went into the chamber and installed the corner cube. I'm not sure what state the ACB is normally in when the cube is attached, but it is in the lowered position right now, which made install of the cube precarious. Greg was able to do it, but it didn't look easy. Otherwise, we are ready for IAS to start working.