Argonne National Laboratory

Experimental Physics and
Industrial Control System

1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  <2017 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
<== Date ==> <== Thread ==>

Subject: Re: Default value to field SCAN
From: Andrew Johnson <anj@aps.anl.gov>
To: <tech-talk@aps.anl.gov>
Date: Wed, 4 Jan 2017 11:59:17 -0600
On 01/04/2017 09:29 AM, Dirk Zimoch wrote:
> BTW, I have written an addScan command line function that allows to add
> scan rates in the startup script (rather than modifying menuScan.dbd)
> and which tries to crank up the vxWorks clock rate to at least 4 time
> the scan rate and warns if that is not possible.

The disadvantage with this approach is that database configuration tools
like VisualDCT will not know of the existence of any such new scan rates
so won't present them to the database designer as possible choices for
SCAN field values. This isn't a problem for an expert who doesn't use
VDCT, but it could be confusing for a beginner or someone who doesn't
know about the addScan command.

Note that from Base-3.15 onwards a menuScan choice string can specify a
scan rate in Seconds, Minutes, Hours or even Hertz/Hz, which would
confuse the current addScan() code when matching existing choices.
However the choice strings "10 Hz" and ".1 second" will generate two
different scan threads, and there is no internationalization available
for those unit strings. A more flexible scan mechanism is something I
would like to be able to add, but it might never actually happen.

- Andrew

-- 
Arguing for surveillance because you have nothing to hide is no
different than making the claim, "I don't care about freedom of
speech because I have nothing to say." -- Edward Snowdon

References:
Default value to field SCAN Gabriel de Souza Fedel
Re: Default value to field SCAN Andrew Johnson
Re: Default value to field SCAN Gabriel de Souza Fedel
Re: Default value to field SCAN Andrew Johnson
Re: Default value to field SCAN Michael Westfall
RE: Default value to field SCAN Mark Rivers
Re: Default value to field SCAN Michael Westfall
Re: Default value to field SCAN Dirk Zimoch

Navigate by Date:
Prev: Re: Default value to field SCAN Andrew Johnson
Next: Re: Acromag IP230A/231 support Bruce Hill
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
Navigate by Thread:
Prev: Re: Default value to field SCAN Michael Westfall
Next: Re: Default value to field SCAN 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
ANJ, 14 Feb 2017 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·