Subject: Re: [sloan-25mlog 3842] 2.5m obslog 20180117 (SJD 58136)
From: John Downey
Date: Thu, 18 Jan 2018 06:15:21 -0700
>=20
> Note to engineers and developers:
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D
> 1. axis init cleared all axes. But alt came on after 10' motion. Inter =
locked
> showed that wind-alt was red although the knife switch was turned on =
and green
> light was on. Anyway, tagging the knife switch fixed the problem.
The ALT windbaffle amp is more susceptible to getting stuck in an error =
state than are the other amps - the most common cause I've seen is =
stopping the WB suddenly.
The telescope will usually clear all axes and move in ALT until it hits =
the windbaffle in this case.  I don't think it used to clear the axis in =
such cases, but I didn't work with the old ALT windbaffle drive long =
enough to be certain of this - I just never saw the telescope drive into =
the windbaffle and then stop until we installed the new system.
Power cycling the WB drive clears the error condition if it was =
temporary - such as caused by a sudden stop - so that was what I would =
have recommended.=