jeffrey.kissel@LIGO.ORG - posted 12:07, Tuesday 04 September 2012 - last comment - 11:20, Wednesday 05 September 2012(4070)
How to turn on untrip SUS Watchdogs when SUS has Large Alignment Offset (Current Best Method)
After noticing difficulties with untripping the QUAD watchdogs, I realized that a more sophisticated process is required to restore the QUAD status after a watchdog trip now that there are gigantic P and Y offsets on the TOP stage. Bare with me, it's complicated and convoluted because we didn't imagine this scenario while installing the infrastructure, but it's now on the "to-do" list to get it changed / more straight forward in the future.
For now, the process is as follows:
(1) Turn off the master switch.
(2) Untrip any relevant watchdogs.
(3) Change the gain in the P2P and Y2Y DriveAlign matrix filter banks to 0.00 (you can do this from the screen, or since you (currently) need a terminal open for the next step anyways, you can caput / ezcawrite it too). For example, if you're doing ITMY, that's
]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_P2P_GAIN 0
]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_Y2Y_GAIN 0
(4) Change the ramp time in the P2P and Y2Y DriveAlign matrix filter banks to 10 sec. (The link to the "full" screen is currently broken, so you'll have to do a "caput" or "ezcawrite" or whichever). For example, if you're doing ITMY, that's
]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_P2P_TRAMP 10
]$ caput H2:SUS-ITMY_M0_DRIVEALIGN_Y2Y_TRAMP 10
(5) Turn ON the P and Y offsets to the desired value (if they're not on already); turn ON the damping loops (if they're not on already)
(6) Turn ON the MASTER SWITCH
(7) Change the gain of the P2P and Y2Y DriveAlign matrix filter banks back to one. Now that there's a ramp time in the signal chain, it'll slowly ramp up the offsets (and the P and Y damping loops), so the watchdogs won't trip.
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The items on the "to do list" in order of difficultly/level of hackiness (from easiest / hackiest to most difficult / do-the-right-thingiest)
(1) Fix the DriveAlign Matrix sub-screen such that
(a) The "FULL" button works, and it opens the full filter bank (may just require an userapps svn up...)
(b) Add the TRAMP epics read/write to every element of the the upper level DriveAlign screen-
(2) Update the auto-damping script to include the above sophistication
(3) Offload what offsets you can to ISI and/or HEPI
(4) Make a model change such that the P and Y alignment offsets can be ramped (e.g. make the DCDRIVECAL gain a full filter bank, or add a ramp to the MASTER SWITCH, or something)
(5) Ask CDS to make the cdsEpicsIn block generate a TRAMP channel as well as a value channel on compile.
Garcia has volunteered to take on items (1) and (2) for now.
The previously-broken links in the "SUS_CUST_QUAD_M0_DRIVEALIGN.adl" file have been repaired. The auto-generated filter module medms created by the RCG have had their filenames adjusted to a format resembling: "H2SUSITMY_ITMY_M0_DRIVEALIGN_L2L.adl" as opposed to a format previously used: "H2SUS_ITMY_M0_DRIVEALIGN_L2L.adl" The generic files are located locally: "/opt/rtcds/lho/h2/medm/h2susitmy/H2SUSITMY_ITMY_M0_DRIVEALIGN_*2*.adl" The custom medm file for the DRIVEALIGN overview ("/opt/rtcds/userapps/trunk/sus/common/medm/quad/SUS_CUST_QUAD_M0_DRIVEALIGN.adl") was edited to point to the correct filenames.