 23 Feb 2022, Stefan Ritt, Info, Midas slow control event generation switched to 32-bit banks
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The midas slow control system class drivers automatically read their equipment and generate events containing midas banks. So far these have been 16-bit
banks using bk_init(). But now more and more experiments use large amount of channels, so the 16-bit address space is exceeded. Until last week, there
was even no check that this happens, leading to unpredictable crashes.
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 03 Mar 2022, Stefan Ritt, Bug Report, Writting MIDAS Events via FPGAs
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> Starting the frontend and starting a run works fine -> seeing events with mdump and also on the web GUI.
> But when I stop the run and try to start the next run the frontend is sending no events anymore.
> It get stuck at line 221 (if (status == DB_TIMEOUT)).
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16 Mar 2022, Stefan Ritt, Info, New midas sequencer version
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A new version of the midas sequencer has been developed and now available in the
develop/seq_eval branch. Many thanks to Lewis Van Winkle and his TinyExpr library
(https://codeplea.com/tinyexpr), which has now been integrated into the sequencer
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21 Mar 2022, Stefan Ritt, Bug Report, Python ODB watch
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What you describe is a well-known problem with the ODB. At PSI we have similar issues. There are
two approaches to solve it:
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22 Mar 2022, Stefan Ritt, Info, New midas sequencer version
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After several days of testing in various experiments, the new sequencer has
been merged into the develop branch. One more feature was added. The path to
the ODB can now contain variables which are substituted with their values.
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22 Mar 2022, Stefan Ritt, Bug Fix, fix for event buffer corruption in bm_flush_cache()
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Thanks Konstantin for your detailed description.
I wonder why we never saw this problem at PSI. Here is the reason: In multil-threaded environments, we never call bm_send_event() directly
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24 Mar 2022, Stefan Ritt, Bug Fix, mhttpd bug fixed
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> 1st wget stops (by ctrl-C), socket is closed, mongoose frees it's mg_connection object
> (corresponding worker is still labouring, hmm... actually sleeping, and now has a stale nc pointer)
>
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24 Mar 2022, Stefan Ritt, Bug Fix, fix for event buffer corruption in bm_flush_cache()
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> > ... instead of struggling with all your locks.
>
> it is better to have midas fully thread safe. ODB has been so for a long time,
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24 Mar 2022, Stefan Ritt, Bug Fix, mhttpd bug fixed
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I see, now I understand.
As for the browser cache problem: This Chrome extension is your friend:
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24 Mar 2022, Stefan Ritt, Bug Report, data missing in runXXXXXX.mid
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One idea: we should have a look at mlogger::close_channels(). There the SYSTEM buffer is emptied through the cm_yield() call. Instrumenting this with some
debugging code will enlighten us.
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31 Mar 2022, Stefan Ritt, Suggestion, Maximum ODB size
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Anybody some idea what the maximum ODB size can be? In the old days, the linux
kernels had a severe limit on shared memory of usually 8MB, but in the age of
64GB RAM being a standard, we should be able to grow bigger. Tried
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13 Apr 2022, Stefan Ritt, Info, ODB JSON support
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> Per xkcd, there is a new json standard "json5". In addition to other things, numeric
> values NaN, +Infinity and -Infinity are encoded as literals NaN, Infinity and -Infinity (without quotes):
> https://spec.json5.org/#numbers
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15 Apr 2022, Stefan Ritt, Info, New midas sequencer version 
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I prepared some slides about the new features of the sequencer and post it here so
people can have a quick look at get some inspiration.
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02 May 2022, Stefan Ritt, Info, added web page for "mdump"
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Here are some of my thoughts:
- I volunteer to write the JavaScript midas bank decoder. Just a couple of pure javascript functions, no
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04 May 2022, Stefan Ritt, Info, added web pages for "show odb clients" and "show open records"
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Concerning the "scl" page, we are currently having a discussion. At the moment, one can
see midas clients in three different places:
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06 May 2022, Stefan Ritt, Info, Increased timeout for program shut down
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We had the problem in our lab that a frontend took about 6 seconds to gracefully
shut down, mainly it needed to park some motors. I found that the shutdown command
had a hard-coded timeout of 5 seconds, after which the frontend gets killed, and
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08 May 2022, Stefan Ritt, Info, RO_STOPPED with triggered events
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We had issues in one of our experiment that people used RO_STOPPED in the
equipment list together with triggered events (EQ_USER). If events are sent when
a run is stopped, this leads to many unexpected results, so I added a check in
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17 May 2022, Stefan Ritt, Info, RO_STOPPED with triggered events
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> > > some old front-end are not running any more since they do use RO_ALWAYS together with
> > triggered events.
> >
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20 Jun 2022, Stefan Ritt, Forum, Alarm on variable not updating
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There are two functions to do that, one check the last write access, the other the last write access if the run is running. The alarm condition looks like:
access(/Equipment/.../Variables/Input[10]) > 60
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05 Aug 2022, Stefan Ritt, Info, Information for midas updates though git
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Several submodules of midas have been re-organized, so if you want to pull the
newest version, you need a
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