Date: Sun, 21 Jun 2015 22:02:23 -0000 (UTC)
Subject: Re: [sloan-25mlog 2362] Re: 2.5m obslog 20150620 (SJD 57194)
From: "Dmitry Bizyaev"
Hi Dan,
thank you for the clarification!
Unfortunately, we experience a chain of false correlated events, that made
last night unusual and looked like a building problem.
We clearly overlooked the non-5 degree altitude of the telescope in the
evening. It looked normal, more over, finally we opened the building not
interfering with the telescopes. I'm in doubt that interlock-because of
the telescope's position,- was evolved in the evening case. The building
started opening smoothly without the interlock. The building started
moving. After moving it ~ 4 feet I released the button and pushed it again
in a few seconds, - building did not move. Interlock did not show anything
useful in this case. After Joe inserted the bypass, and then removed it
right away, it started moving.
In the morning it was a "correlated" problem, but not real. Telescope did
move not the full way down to 5 degrees, and the building did not start
because of this reason. First thing we thought is "this is the dame
problem as in the evening". So the immediate solution was to do the same
as Joe did. We inserted the bypass and started moving the telescope. After
a few moments, we checked the altitude of the telescope and corrected it.
Should we had no evening problem (whose reason is still puzzling to me),
in the morning we would check the altitude first. As a result, nothing
wrong happened, nothing is broken, no night operation time lost.
Best wishes,
Dmitry
> I went through the tpm data from the PLC.  The reason the building permit
> was not granted was because the altitude was not low enough to actuate the
> switch to tell the PLC it was in the right place.
>
> In the evening, it appears the altitude was a little above the nominal
> opening position (possibly it drifted up enough when the stop button was
> pressed to be right on the edge of the switch).  In the morning it was
> clearly too high (by about 4 degrees), and that is why the building motion
> permit was not granted.
>
> -Dan
>
>
> What follows are the gory and cryptic details of my digging  (mostly for
> my records).
>
> Looking at  tpm_ABI7_00
>
>
> Before Opening:
>
> 65344   1111 1111 0100 0000
>
> Starting to open:
>
> 02:14:13Z  65380  1111 1111 0110 0100
>
> Building permit not granted because altitude was not low enough ( not set)
>
> 02:14:20Z  65383  1111 1111 0110 0111
>
>
> 02:14:51Z  57191  1101 1111 0110 0111
>
> Bit is now set
>
> 02:15:08Z  57335  1101 1111 1111 0111
>
>
> 02:15:13Z  57332  1101 1111 1111 0100
>
>
> 02:15:28Z  55284  1101 0111 1111 0100
>
>  tpm_ABI7_00
>
> 0 ROT MTR CW PERM IN
> 1 ROT MTR CCW PERM IN
> 2 ROT MTR PERM IN
> 3 SPARE S5 C3
>
> 4 BLDG PERM IN
> 5 ROT PLC PERM IN
> 6 HATCH CLS
> 7 ALT
> 8 ALT > 0.3 DEG
> 9 ALT PIN OUT
> 10 ALT  11 BLDG ON ALT
>
> 12 AZ 109 - 131
> 13 ALT > 18.6 DEG
> 14 AZ STOW 1A
> 15 AZ STOW 1B
>
>
> ALENC1  1,288,680  During this time
>
>
> 30 deg is 7,714,000
>
> 90 deg is 23,142,800
>
>
> Closing  2,279,328   --->  1,285,690
>
>
>  enough
>
> 11:27:04   55287  1101 0111 1111 0111  After alt moved to 5
>
>
> On Jun 21, 2015, at 7:48 AM, Dan Long wrote:
>
>> Hi all,
>>
>> If putting in the bypass got the enclosure to move, then there was a
>> problem with one of the building interlocks.  From the description it
>> sounds as if one of the switches was on the edge of having its condition
>> met.
>>
>> There are basically three building motion interlocks.  The west door
>> being all the way up, the hatch being closed, and the telescope in
>> position (az at stow, alt at 5 deg).
>>
>> In the evening, my money would be on the hatch switch.  In the morning,
>> it was because the telescope wasn't low enough in altitude.  Please
>> remember that one of the parts of the opening and closing procedure is
>> to visually verify the altitude is where it needs to be, and being extra
>> cautious is vital when any interlock is bypassed.
>>
>> -Dan
>>
>>
>> On Jun 21, 2015, at 5:47 AM, kgrabowski@apo.nmsu.edu wrote:
>>
>>>
>>>                      APACHE POINT OBSERVATORY SDSS 2.5M
>>>
>>>                                OBSERVING LOG
>>>                         Saturday June 20, 2015
>>>
>>>                                 (SJD 57194)
>>>
>>> ----  Observing Team ----
>>>
>>> Dmitry Bizyaev
>>> Katie Grabowski
>>>
>>> Joe Huehnerhoff
>>>
>>>
>>> ---- Observing Summary ----
>>>
>>> The LN2 dewars are low (>> observations).
>>>
>>> When we opened and closed, the building had to be moved with the
>>> interlock. More
>>> details in log and Problems sections.
>>> Clear, productive night.
>>>
>> .
>> .
>> .
>>>
>>> Night
>>> -----
>>> 2:25Z-When we opened at sunset, the enclosure movement was started and
>>> stopped.
>>> When we tried to restart the enclosure movement, it would not move in
>>> either
>>> direction. We reset the building control panel, to no avail. No
>>> interlocks were
>>> tripped. Joe put in the bypass key and moved the enclosure
>>> successfully. When we
>>> tried to move the building without the key, it worked in both
>>> directions.
>>>
>>>
>> .
>> .
>> .
>>> ---- Problems in Detail ----
>>>
>>>
>>> Enclosure Movement at Sunset:
>>>
>>> 2:30Z-When we opened at sunset, the enclosure movement was started and
>>> stopped.
>>> When we tried to restart the enclosure movement, it would not move in
>>> either
>>> direction. We reset the building control panel, to no avail. No
>>> interlocks were
>>> tripped. Joe put in the bypass key and moved the enclosure
>>> successfully. When we
>>> tried to move the building without the key, it worked in both
>>> directions.
>>>
>>> Enclosure Movement in the Morning:
>>>
>>> 11:20Z- When we used the GoTo5 script in the morning, the move didn't
>>> decelerate, and the brake went on when the telescope was at 8.8
>>> degrees. We
>>> tried to move the building, with no luck. The building interlock was
>>> bypassed,
>>> but we realized that the telescope was not at 5 degrees. We moved the
>>> enclosure
>>> away from the telescope, the telescope to 5 degrees, and then moved the
>>> enclosure over the telescope successfully.
>>>
>>> ____________________________________________________________
>>> Logs of Nightly APO Activities
>>> https://trac.sdss.org/tracmailman/browser/private/sloan-25mlog/index.html
>>
>
> ____________________________________________________________
> Logs of Nightly APO Activities
> https://trac.sdss.org/tracmailman/browser/private/sloan-25mlog/index.html
>