Experimental Physics and
Industrial Control System

John Sinclair <[email protected]> · Thu, 08 Nov 2007 13:30:01 -0500

Brian,
Here's something to try.
When edm gets in this state, mouse over some widget that should be
updating and do a ctl-middle-button press. A window will pop up showing
the connection info for the pv and the number of value changes that have
occurred. Then use another utility such as probe to watch value-change
events. When you are certain a significant value change has occurred, do
another ctl-middle-button press to see if edm agrees (by indicating a
greater number of value changes than before and a new timestamp). If so,
I would suspect some component of XWindows. If not, it could be a bug in
edm or a channel access issue.
John sinclair
Brian Bevins wrote:

Hi Dirk,
We haven't been running MEDM on RHEL so I don't know if it's showing
the same problem for us. I can confirm that the behavior you describe
matches what has been reported to me by operators using EDM on RHEL.
Exposing the window seems to solve the problem.
An X/Motif problem does seem like a possibility. We recently had to
turn off the BIG-REQUESTS extension on the RHEL X servers because it
generated errors for certain other (non-EPICS) applications. Does
anyone know if this might be a problem for EDM? We're using xorg-x11
6.8.2 release 1.EL.19.
--Brian
Dirk Zimoch wrote:

Hi Brian,
we have seen the same effect with MEDM. I suspect a problem with
either the X-server or the motif library. It is very strange that the
effect appears only on some computers.
It seems that the screens don't get update requests when new values
arrive. Minimizing and maximizing, or just "wiping" the screen with
some other window generates the update events and the current value
is shown. From this I conclude that there is no problem in EPICS and
the monitor events correctly arrive. The values are just not updated
on the screen. Can you verify this with EDM?
Dirk
Brian Bevins wrote:

We are in the process of converting our control room machines from
HP-UX 11.11 to RedHat Enterprise Linux (rhel) 4WS. Most things seem
to be working fine, but an odd problem has cropped up with EDM that
we did not have on HP-UX.
Every now and then an EDM display will simply stop showing any
updates to the PV's. Closing and re-opening the display gets it
working again. Writes from the screen to the ioc's seem to work
normally.
Has anybody else experienced a problem like this?
We are using EDM 1-10-2 on rhel 4WS (Nahant Update 5). This is the
same version we have bee using on HP-UX with no problems.
Our operators love how zippy EDM runs on their new Linux boxes
compared to the ancient HP hardware, but this is really denting
their enthusiasm.
Thanks,
--Brian

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System