Subject: Re: [sloan-25mlog 3682] 2.5m obslog 20171001 (SJD 58028)
From: John Downey
Date: Mon, 2 Oct 2017 07:00:54 -0600
>=20
>=20
> * problem with sp1dag connection. It lost after second exposure of =
plate 10016.
>=20
> 02:05:27 OBSERVER.karen 99 sop e text=3D"BOSS failed on 900s science =
exposure"
> 02:06:03 OBSERVER.karen 99 sop f text=3D"Failed one dither of a manga =
dither sequence"
> 02:06:03 CmdDone: OBSERVER.karen 99 sop doApogeeMangaSequence    =
count=3D2
> mangaDithers=3D\"CC\"
>=20
> 02:17:09 -- we have troubles with connect to the sp1daq via boss
> reloadControllers controllers=3Dsp1daq
> 02:40 -- JohnD come on telescope to fix that. He did reset the =
powercycle the SP1.
>=20
Chassis was power cycled because there were no communications lights on =
the ethernet port and both power supplies had multiple trouble lights.  =
Under the circumstances I'm a bit surprised that this worked at all and =
the problem did not come back last night (looks like it may be back this =
morning).
Viktor pointed out that there had been moisture on the RS-232 plug when =
Kaike had him come down to check on the connection.  I think that the =
new foam insulation we tried on the SP1 fill lines is not as good as the =
old, though it certainly is more tidy than the old stuff.  This did not =
likely  cause this problem of moisture in the chassis (Connie noted =
residue inside when working on fixing the SP1 problem at the end of =
summer shutdown) but it did probably aggravate an existing problem.
It will not be feasible to replace this insulation during the observing =
season, as doing so requires removing the secondary dewar.  We may be =
able to wrap the offending fill lines in additional white insulation =
strips to better insulate them.  We may also be able to install a drip =
shield like the one that is used on the R2 camera - but that will be a =
bit harder to sort out that R2's since this problem comes up not at =
stow, but when observing and moving to a variety of positions.  At stow =
the spectrograph electronics is out of the line of dripping.=