Experimental Physics and
Industrial Control System

Arne Freyberger <[email protected]> · Fri, 26 Nov 1999 16:16:46 -0500

Hi:
>
> I would like to make a few PV's available (read-only) to our collaborators
> through a web browser, strictly low performance.  What approach has been
> used for this?  Do I need to program in Java and use JCA ?  Or,  are there
> unix/scripting  tools that can be applied?

I colleague forwarded this thread to me.  

The Hall-B end station
at JLAB has had a read-only web interface for about a year and a 
half now.  The concept is similar to some previous described
in the note, but it does go a bit further (i think).

We store information on ~150 variables in a SQL database (mini-SQL).
The update information is gathered via a perl script (although
C would work as well).  Once in SQL it is relatively straight
forward to write a perl script to retrieve the information and
post it on the web.

The one-minute information is retained for 4 days, after which we only 
keep information at the 10minute rate.

We also use gnuplot to  generate strip charts and scatter plots.

The present server is a 200MHz PII, running Linux OS, apache
web server with mod_perl.  Mod_perl really speeds up the
cgi response of your server.

If you want to have a look (rather boring at the moment since
the lab is down for the gorging) check out:

http://claspc1/cgi-bin/EPICS/epics.pl

This page is the generic entry page, special pages
for specific systems  are easy to develop as well.

There is some documentation (old) available at:

http://claspc1.cebaf.gov/~freyberg/EPICS_WWW/

There are many ways to skin this cat, this is
just one of them.  It has worked reliably for Hall-B
and has allowed offsite users to monitor their equipment
in a convenient method. 

Arne

-- 
Arne Freyberger         
JLAB (Mail Stop 12H)    Phone: (757) 269-6268  
12000 Jefferson Avenue  Pager: (757) 249-6268  [email protected]
Newport News, VA 23606   Phax: (757) 269-5800  http://claspc1.cebaf.gov  

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System