EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

1994  1995  1996  1997  <19981999  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  <19981999  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: e2db changes
From: [email protected] (William Lupton)
To: [email protected]
Date: Fri, 2 Jan 1998 09:14:10 -1000
Dear all,

  This is just to let you know that I have fixed a few problems with
[the excellent] e2db, starting from the version distributed as
EDIF_DB1_0_patches, which I obtained from LANL in early July 1997. I
hope that these fixes don't conflict with or duplicate work that has
been done elsewhere.

  Briefly, the changes are:

1. check for a non-existent "bundle net" (which avoids a SEGV crash that
   sometimes occurs - I'm not sure of the exact triggering circumstances
   - when you have a bus that is connected to nothing)

2. added attempt to use bus name whan fail to find a bus with the same
   name as a hierarchical connector (avoids the need to give buses which
   have bus taps the same name as their hierarchical connectors)

3. ignored any part of a wire name that begins with a double underscore
   (this appears to happen occasionally, with a trailing sequence number
   following the double underscore; the wire name parsing routine
   couldn't handle this, with the result that such wires were
   essentially ignored)

4. fixed EDIF file parse error which did not handle properties on wires
   (the property name overwrote the wire name in the parse tree and thus
   essentially caused the wire to be ignored)

The result is that some perplexing failures to make connections
involving buses have been resolved (previously I had hit cases where
apparently legal schematics were failing to result in the expected
connections in the .db files; deleting and re-drawing wires at random
would usually fix these problems but I would never know why; I suspect
that this was usually the "double underscore" problem).

  There are some other things that would, I believe, be worth doing to
e2db. For example:

1. allow connections via hierarchical symbols to work via "sub-buses"
   (e.g.  tracking bus[1] through bus[0-2] where bus[1-2] is tapped off;
   this doesn't currently work because there is no wire named bus[1] in
   the destination diagram; the logic to realize that bus[1] is a subset
   of bus[1-2] needs to be added)

2. allow "alias" symbols to work (these rename buses and would allow
   "fat" buses in top-level diagrams to be broken out to "thin" buses in
   lower-level diagrams; this would encourage more use of buses and,
   therefore, fewer connections on top-level diagrams, and would support
   a more "DFD-like" Capfast programming technique)

3. detect more Capfast layout errors (e.g. an attempt to connect an OUT
   field to a DOL field is almost certainly an error if the wire is not
   also connected to a VAL field but does not result in an error;
   instead, no connection is made in the .db file)

  I would be happy (at some stage) to make some or all of these changes
(although aliases might be hard) but would like to get a feel for who
else is interested and maybe even working in parallel on similar
problems.

  A Happy New Year to all,

  William

Navigate by Date:
Prev: MEDM for Windows NT Mark Rivers
Next: RE: MEDM for Windows NT (I have also done this for Linux) Hammonds, John
Index: 1994  1995  1996  1997  <19981999  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: MEDM for Windows NT Mark Rivers
Next: Re: e2db changes Rozelle Wright
Index: 1994  1995  1996  1997  <19981999  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, 10 Aug 2010 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·