EPICS Home EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

Format page
for printing


Search Tech-talk
1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  <2008>  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  <2008>  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
<== Date ==> <== Thread ==>
Subject: Re: recordGenerator record
From: Ned Arnold <[email protected]>
To: Kalantari Babak <[email protected]>, [email protected]
Date: Fri, 24 Oct 2008 09:26:51 -0500

"Hot add/delete" has been an often discussed desirable feature for the past 15 years ... I'm not surprised that someone has actually attempted it ... go for it !

However, this approach might be a bother if you have to do an unplanned reboot after someone has added several new record instances ...

Other discussions I've heard hypothesized reloading .db files (without rebooting) so a reboot would always catch the latest ...  maybe add the feature to your record to read the .db file and skip over any records that already exist ???

Just a thought ...

   Ned


----- Original Message -----
From: Steve Lewis <[email protected]>
Date: Friday, October 24, 2008 9:15 am
Subject: Re: recordGenerator record
To: Kalantari Babak <[email protected]>
Cc: [email protected]

> This is definitely a good idea.  I often wish I had just
> one more
> calc record on a running IOC so I could add a derived value
> (power
> from voltage and current; take a logarithm; etc).  You can
> always
> leave a few around named "temp_1", "temp_2" and so forth, but
> this
> seems much more elegant.  Another use is adding a history
> record.  To
> avoid any lock-set issues, records like these can always use
> "CPP"
> links--which I do anyway in such circumstances since I don't
> like to
> clutter the "hard" code with forward links to "soft" code.
>
> At 3:56 PM +0200 2008/10/24, Kalantari Babak wrote:
> >I have spent some time on writing a new EPICS record type which can
> >create new record instances at IOC runtime. At the moment the
> code is in
> >very preliminary level but it works. "It works" means I am able to
> >generate instances of almost any record types at IOC runtime. The
> >behavior is as the following:
> >
> >1. User specifies record type e.g. "ao", "calc", etc. by CA/DB-
> write to
> >a field of "recordGenerator" record
> >
> >2. User specifies the channel name by CA/DB-write to a field of
> >"recordGenerator" record
> >
> >- As a result a channel with soft device support (soft channel) with
> >corresponding type and name is generated.
> >
> >The generated records behave like a normal record which is
> generated at
> >init time from static EPICS database (template files). They can be
> >accessed by clients, linked to other records, etc. I have
> mainly used
> >facilities provided by "dbStatic" library to do this
> implementation. I
> >had some difficulties with lock-sets but made a work-around
> just to get
> >it working, but I believe it can be done in a proper way.
> >
> >One potential usage of this may be to have (soft) waveform
> records which
> >can have changeable size. One way to do this is to copy the
> content of
> >the generated waveform record, then delete existing record and
> generate>another one with the new size and fill it in with the
> data copied from
> >the previous waveform.
> >
> >The questions to me are:
> >
> >1. are there any interests (now/in future) in such a record
> type, in
> >another word, is it worth at all to put efforts for such thing?
> >
> >2. (if yes) what features such record type can/must have?
> >
> >Any idea/comment is welcome.
References:
recordGenerator record Kalantari Babak
Re: recordGenerator record Steve Lewis
Navigate by Date:
Prev: Re: Installing Sequencer program Janet Anderson
Next: Re: recordGenerator record Andrew Johnson
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  <2008>  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
Navigate by Thread:
Prev: Re: recordGenerator record Steve Lewis
Next: Re: recordGenerator record Andrew Johnson
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  <2008>  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
ANJ, 02 Sep 2010 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·