Experimental Physics and
Industrial Control System

Maren Purves <[email protected]> · Fri, 24 Aug 2007 09:20:14 -1000

Emmanuel Mayssat wrote:

Another question about software upgrade...
Let's say that I change the name of PV in my epics database.
Potentially with this change, I could break epics extensions.
Medm of course, but also feedback system, PV backup, etc.
Is there a way to know which extensions will break if I change a PV

name?

maybe this is nitpicking, but I had a problem reading this
email because it doesn't "break extensions". They'll still
compile and all that. What it does break is the proper working
of your particular incarnations. If you implement those
with variable substitutions they won't break - unless you
run into a similar problem that we have with some of our
dm screens:
The database (in capfast) contains records (what breaks
is the mbbis and mbbos) that have certain fields, and
certain numbers of those. If you then overload those with
pvload and dm screen that was running from before will have
the names (and numbers of items) in the database rather than
those that were loaded with pvload afterwards. Any dm
(replace by your favorite display package) screen that is
run up later with have the ones that were pvloaded and are
actually present in the database at the time.
I still wouldn't consider that 'breaking extensions'.
Aloha,
Maren

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System