From: Kaike Subject: Re: [sloan-25mlog 6285] 2.5m obslog 20221013 (SJD 59866) Date: Fri, 14 Oct 2022 14:17:01 -0600 --Apple-Mail=_48BBEF0D-2A82-4720-B312-7FCF9E4D4794 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Oct 14, 2022, at 12:57 PM, John wrote: >=20 >=20 >=20 >> On Oct 14, 2022, at 12:49 PM, Kaike wrote: >>=20 >>=20 >>=20 >>> On Oct 14, 2022, at 7:24 AM, John wrote: >>>=20 >>>=20 >>>>=20 >>>> ---- Engineering Issues ---- >>>>=20 >>>> 1. 04:47Z: The rotator went out_of_closed_loop, then altitude went = out of close loop too at the same region we had trouble with last night = during a slew to a new field. The field destination is = AZ/ALT/ROT=3D-154.4/45.8/123.2. The rotator went out_of_closed_loop near = 116. The rotator drive-motor voltage spiked to 12K at that moment. We = slew the telescope up in altitude to 60 degree, slew the rotator to the = destination 123.0 degree, then gotoField again. It reached there without = issue.=20 >>>>=20 >>>> 06:37Z: This similar happens again at 06:37Z. Rotator went = out_closed_loop at 110 with a destination of 146, and altitude at 43 = )with the destination at 34 degrees. Apply the same trick, slew the = altitude to 60, then rotator to 146, the following HAL gotoField = succeed.=20 >>>>=20 >>>> Total 8 minutes was lost.=20 >>>=20 >>> Ok, this is sounding a lot like either rotator balance or a binding = issue. I remember there are areas where the wrap tends to bind, I=E2=80=99= ll look in my old notes. >>>=20 >>> For what it=E2=80=99s worth, we think that the ALT following the ROT = on going out of closed loop may be the sudden stop of the rotator = putting an added torque on the ALT axis and upsetting it=E2=80=99s = balance a little. It sounds like this is usually happening with the = rotator going the same direction each time, is that a reasonable = assumption? >>=20 >> This makes sense.=20 >=20 > I think the balance of both the rotator and altitude are probably = pretty marginal. I doubt this is a can of worms we really want to open = right now however, correcting the rotator is going to involve removing = the IEB and checking how it balances vs our remaining spectrograph. >=20 >>>=20 >>>>=20 >>>> 2. connections to servers/computers has intermittent slowness = issues. All of these seems associated with /data, for example, Kronos = and SOS slows down. can someone check /data IO? Thanks >>>=20 >>> This one is not engineering. >>=20 >> This belongs to the site IT staff.=20 >=20 > Right, site IT staff do not work for the engineering group. It needs = its own heading if you are going to split up issues under headings. We have added two sections to the log, can discuss whether another = section should be added. Normally, we don=E2=80=99t have many notes for = IT staff, likely less than a half dozen per year. For the time being, we = could simply add =E2=80=9Cto IT staff=E2=80=9D or similar words on IT = relevant items.=20 >=20 >>=20 >>>=20 >>>>=20 >>>> ---- Software Issues ---- --Apple-Mail=_48BBEF0D-2A82-4720-B312-7FCF9E4D4794 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 On Oct 14, 2022, at 12:57 PM, John wrote:On Oct 14, 2022, at 12:49 PM, Kaike = wrote:On Oct 14, 2022, at 7:24 AM, John wrote:---- Engineering Issues ----1. = 04:47Z: The rotator went out_of_closed_loop, then altitude went out of = close loop too at the same region we had trouble with last night during = a slew to a new field. The field destination is = AZ/ALT/ROT=3D-154.4/45.8/123.2. The rotator went out_of_closed_loop near = 116. The rotator drive-motor voltage spiked to 12K at that moment. We = slew the telescope up in altitude to 60 degree, slew the rotator to the = destination 123.0 degree, then gotoField again. It reached there without = issue. 06:37Z: This similar happens again at 06:37Z. = Rotator went out_closed_loop at 110 with a destination of 146, and = altitude at 43 )with the destination at 34 degrees. Apply the same = trick, slew the altitude to 60, then rotator to 146, the following HAL = gotoField succeed. Total 8 minutes was lost. Ok, this is sounding a lot like = either rotator balance or a binding issue. I remember there are = areas where the wrap tends to bind, I=E2=80=99ll look in my old = notes.For what it=E2=80=99s worth, we = think that the ALT following the ROT on going out of closed loop may be = the sudden stop of the rotator putting an added torque on the ALT axis = and upsetting it=E2=80=99s balance a little. It sounds like this = is usually happening with the rotator going the same direction each = time, is that a reasonable assumption?This makes sense. I think the balance of both the rotator and altitude are = probably pretty marginal. I doubt this is a can of worms we really = want to open right now however, correcting the rotator is going to = involve removing the IEB and checking how it balances vs our remaining = spectrograph.2. connections to servers/computers has intermittent slowness = issues. All of these seems associated with /data, for example, Kronos = and SOS slows down. can someone check /data IO? ThanksThis one is not engineering.This belongs to the site IT = staff. Right, site IT staff do not work for the engineering group. = It needs its own heading if you are going to split up issues under = headings.We = have added two sections to the log, can discuss whether another section = should be added. Normally, we don=E2=80=99t have many notes for IT = staff, likely less than a half dozen per year. For the time being, we = could simply add =E2=80=9Cto IT staff=E2=80=9D or similar words on IT = relevant items. ---- Software Issues = ----= --Apple-Mail=_48BBEF0D-2A82-4720-B312-7FCF9E4D4794--