CSS web opi Re: medm GUIs with html

["Kasemir, Kay" <kasemirk@ornl.gov>]

Hi:

Configuring the web opi is quite easy, see presentation at the Korean
EPICS meeting
http://pal.postech.ac.kr/epics2012/program.jsp
http://pal.postech.ac.kr/downloadServlet?file_path=/home/pal/ROOT/epics2012
/files&file_name=program/1025-CSS_1_3_WebOpi.pdf


1) Have tomcat
2) Drop webopi.war binary in Tomcat/webapps
3) Set some properties similar to EPICS CA address list and the directory
where your *.opi files are
4) Copy the *.opi files (CSS BOY files) there

The advantage of that approach: You can see BOY displays in a web browser
with zero additional translation work.
They work almost exactly like the standalone CSS version, but that can
also be the issue.
This approach basically provides each web client with an instance of the
CSS BOY code running on the web server.

If your use case is a beam line, where beam line personnel created some
displays, and the 1 or 2 people working on the beam line sometimes need to
see those screens in a web browser while at home: Perfect, because it's
nearly zero added work. Just copy the *.opi to the web server, and it
behaves just like sitting in front of CSS BOY at the beam line, maybe a
little slower update rate.
Depending on your web server and CA gateway, you could even allow write
access.
Beam line users have created a new display that they also want to see:
Just copy it to the web server.

On the other hand, if your use case is a site-wide status display, where
each morning 100 people want to look at that same web display to see how
the machine is doing today: Not a good approach because you end up with
100 instances of the CSS BOY code.
User 1 connects, web server starts an instance of BOY, which loads the
*.opi file, connects to PVs, ..
User 2 connects, web server starts another instance of BOY, which loads
the *.opi file, connects to PVs, ..
..
The PV connections are actually cached, but for 100 people looking at the
same *.opi file, you still have 100 copies of the same *.opi file.
For this, you'd rather have something running on the web server that gets
the information once, and then serves cached data.


Thanks,
Kay





From:  Tim Mooney <mooney@aps.anl.gov>
Date:  Monday, December 17, 2012 16:05
To:  James F Ross <james.falconer.ross@gmail.com>
Cc:  "tech-talk@aps.anl.gov" <tech-talk@aps.anl.gov>
Subject:  Re: medm GUIs with html


Hi James,
If I had to do this, I'd convert the MEDM displays to CSS-BOY (very easy),
and use webopi:
http://sourceforge.net/apps/trac/cs-studio/wiki/webopi
I've never tried webopi.

Tim

________________________________________
From: "James F Ross" <james.falconer.ross@gmail.com>
To: "EPICS Tech Talk" <Tech-talk@aps.anl.gov>
Sent: Monday, December 17, 2012 2:38:00 PM
Subject: medm GUIs with html

Greetings everyone,
It would be very convenient for my group (STAR slow controls) to display
MEDM GUIs on a web page.  Has anyone done anything like this before?  I
was wondering if there were a way to either convert a GUI to a web format
through MEDM or to simply execute one or more an medm .adl files so they
display in real time online.

Thanks!
James Ross


-- 
Tim Mooney (mooney@aps.anl.gov) (630)252-5417
Software Services Group (www.aps.anl.gov)
Advanced Photon Source, Argonne National Lab