The "slits out on disable" feature has been removed from the ARF software.
Shannon
Mr. Shannon Krause wrote:
> The logic behind having the slits retract when ARF (the Automated Ring
> Fill
> software) is disabled, is to minimize the time required to reestablish
> beam in the ring.
>
> Often ARF is disabled, the hall is opened for work, then 10 hours later
> some random Chief attempts to inject beam into the ring and can not.
> There
> are 100s of things that can cause this problem and the most common
> involves
> RF or magnets. Only after doing all the obvious trouble shooting would
> the crew check the slits and find them inserted. This wasted beam
> time and
> every Chief, including myself was bitten by this same oversight. The
> simple solution
> to the problem was to have the slits retract when ARF is disabled.
> Since we
> can't deliver production beam without ARF, there seemed no point in
> leaving
> the slits in when not required by the experiment. Likewise, the slits
> can be
> inserted manually by the crew when ARF is not required.
>
> ARF was modified to include this feature over a year ago and we have
> not lost
> any beam time due to the "slit in" problem since. The issue of
> rebooting
> the HV control software ioc was not considered at the time and I'm
> surprised
> this wasn't an issue before.
>
> However, we will remove this "slits out on disable" feature from the
> software.
>
> We now have the mode selector in EPICS, so we can provide a sophisticated
> alarm to alert the crew that the slits are inserted at inappropriate
> times and avoid
> the "slits in" problem by a new method. The new code will probably be
> ready
> sometime next week or sooner if possible.
>
> Shannon
>
>
> Adam Jon DeGrush wrote:
>
>> I agree w/ Tancredi. It doesn;t make much sense.
>>
>>
>>
>> On Thu, 19 Feb 2004, Tancredi Botto wrote:
>>
>>
>>
>>> Hi, indeed the slits move out after you reboot the hv IOC for the
>>> simple reason that the autofill is not enabled. From my perspective,
>>> I failed to understan why.
>>>
>>> Maybe we should fix this. Shannon ?
>>>
>>>
>>>
>>>> i think that, last week during one of my shifts, i was the first
>>>> person to
>>>> experience the mass HV tripping. during a later shift (with
>>>> Jason), we
>>>> once again experienced it. it turned out that, both times, the
>>>> mass HV
>>>> tripping occurred right after we rebooted the ioc (via ./BOOT). the
>>>> problem during those shifts was that after a reboot, the slits were
>>>> going
>>>> out but the GUI (on dblast13) said that they were still in. we had
>>>> CCR
>>>> verify this (ask Jason; he was there).
>>>>
>>>> if HV problems still exist, it may have something to do with the slits
>>>> going out after an ioc reboot. i asked adam about this, and he
>>>> said that
>>>> the slits should be independent of rebooting the ioc. perhaps this
>>>> isn't
>>>> the case. or perhaps the slit problems during my shifts were just
>>>> flukes...
>>>>
>>>> aaron
>>>>
>>>>
>>>
>>>
>>
>
-- Shannon Krause Accelerator Operations Group Leader MIT Bates Linear Accelerator Center 21 Manning Rd. - P.O. Box 846 Middleton, MA 01949, USA617-253-9206 krause@mit.edu
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