Experimental Physics and
Industrial Control System

Peter Milne <[email protected]> · Wed, 01 Apr 2015 18:54:08 +0100

Hi Pete

On 01/04/15 18:13, Pete Jemian wrote:

We encountered this same situation when building controls for the XIA
PF4 filter (attenuator) box.  The PF4 allows one to place 4 separate
foils into the beam.  The X-ray attenuation of the PF4 is based on the
combination of foils in the beam.  Attenuation varies by X-ray
wavelength, thus the nice text on the MBBO button labels would change,
ideally, when the X-ray wavelength is changed.  (A SNL program computes
the values.)

Our work around was to place the changeable text in stringout labels
next to each mbbo radiobutton value.  Not our first choice for controls
but acceptable to the users.

I've been hit by this issue too.
Seems like your solution might be the simplest offered so far.

Help my understanding please:

Is it the case that the MBBO button shows "this is what it was when the

screen started, or what you last requested on this screen", while the

Stringout shows "this is what it actually is now" (perhaps because some

other agent changed it).

Thanks

Peter

see the example "pf4Bankmore.adl" screen in the synApps optics module:

https://subversion.xray.aps.anl.gov/synApps/optics/trunk/opticsApp/op/adl/pf4Bankmore.adl

Pete

On 4/1/2015 11:53 AM, Jameson Graef Rollins wrote:

Hi, all.  We have an application that employs an enum record as a
control interface (for submitting a request to the program).  The
application can be manually prompted to reload it's configuration, which
can occasionally cause the elements of the control enum to change
(desired behavior).

The problem is that our operator interfaces (primarily MEDM at the
moment) do not behave well in the context of these enum change.  All
MEDM enum controller objects retrieve enum identifiers only once at
startup.  This means they become stale after the enum changes, and more
dangerously, allow the user to select one element that is actually
mapped to another.  This has created quite a few headaches for us.

I've been trying to find a way around this problem, but haven't come up
with anything.  The best solution I have so far involves creating a
screen on the fly that creates a shell command menu with a bunch of
"caput" commands for the strings of enum.  This of course doesn't get
updated on application reload either, but it at least doesn't allow for
selecting a mislabeled element.

I'm soliciting for suggestions about how to create operator interfaces
that behave better in the face of changing enum records.  All operator
interfaces that I've looked at (MEDM, EDM, QTDM) don't behave well.  Any
suggestions of what we could do that don't involve patching MEDM or
creating our own operator interface?

jamie.

--
Peter Milne
Director of Sales
www.d-tacq.com

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System