Conference Summary Talk
Wolfgang von Rüden
CERN Geneva and GSI Darmstadt
INTRODUCTION
Let me first of all thank the organizing committee for inviting me to give the conference summary. My thanks go
also to W. Busse, D.R. Myers and R. Rausch for listening to the parallel sessions I did not attend and for giving me
their views on these talks. Progress in desktop computing has been demonstrated in multiple ways during this conference and the ability to project my slides on-line right now is another example. Thanks to the technical supportstaff.
As you may expect I will not attempt to provide a compressed version of all talks in less than one hour, but rather
will try to address the main topics of this conference, sometimes biased by my personal view.
The community represented here comes essentially from four areas of activity: industrial controls, accelerators,experiments and telescopes, an interesting mixture.

MAIN TOPICS
Let me now turn to my selection of main topics.
Control Theory
The field of control theory is very complex. Work is going on steadily with good progress in several domains,
although no exciting breakthrough was presented.
Control Model
We talked a lot about the ‘standard’ model during the past days. Being a physicist by education, I cannot resist thetemptation to present what a physicist sees under this heading, and compare it to what a controls person would
expect:Control Systems

Well, not all that different after all …
The standard model is not sufficient for complex control systems. On a large accelerator, for example, you will find arepetition of similar sub-systems such as cooling plants, electricity installations or vacuum systems. People incharge of a particular system, lets say the electricity distribution, need to see and control all sub-systems from acommon supervisory station using synoptic displays based on their standards. A circuit under power is usuallyshown in red, because it represents a danger for the user. Cryogenic plants use different sets of symbols and will
therefore use their own displays. Let us define such views of parts of the system as ‘horizontal’ views. A person
operating the accelerator or an experiment needs a different view. Firstly, he or she does not want to see thecomplexity of the sub-system, nor the symbols or color conventions used. Green lights mean OK for an operator. A‘vertical’ view providing global information on all subsystems is appropriate. This combination of vertical andhorizontal views could be defined as the ‘extended’ model ofcontrols.

Exp. A

Beamline

Exp. B

Control
RoomCoolingControls Hardware
From the session on controls hardware we have learned ofMagnets• the arrival of powerful risc processors in controls• the acceptance of standard field buses (FIP, Profibus,CAN, etc.)• the existing components satisfy the needs of today andfor the near future (VME, VXI, GPIB, PLCs)• the availability of sophisticated software support(LabView, etc.)

RF‘Extended’ Model of Controls

An interesting example was shown by P. Charrue, the CES PowerPC-based VME card, which was recently selectedby CERN as one of the future standard components for accelerator control systems. It has capabilities similar to
those of a mainframe from not so along ago. The basic demand for CPU power to control equipment has not grownat the same rate as the power available, but the use of more and more sophisticated software accounts for a good
fraction of the required resources.
Software Technology and Methods
In the area of software technology the most remarkable change is the use of object oriented programming. The
arguments in its favor are amongst others modularity, information hiding and re-use. As we control physical objects
and usually a large number of identical devices, OO programming is especially well suited in controls. If one takes
care to design classes which strictly correspond to physical devices, allowing the setting of parameters according tothe options available on the device, a system can be constructed by generating objects automatically from a simple
database. No software changes are needed to compose a system from existing components and, therefore, systems canbe maintained largely by end-users. Object oriented databases slowly find their way into our field, but will they
replace RDBM systems?
Formal software development methods are used at most with hesitation. Although around for more than 15 years,
they are hardly accepted, although the need for a quality system is recognized. I should like to quote Steve Wampler,
who expressed my view on the matter very nicely:“People who write software for big computer projects like to describe themselves asengineers. To deserve the name, they must behave as other engineers do.”In Europe, the software engineering standards developed by the European Space Agency are beginning to enter thephysics research community. At CERN several groups have successfully applied the standard, either partially or as awhole, both for internal development and for sub-contracting. Even some physics experiment teams agreed to follow
the first phase of the standard to define
their user requirements. After initialw
resistance, the benefits were quicklyvieReUser
recognized.
Requirements

Commercial Solutions
With the increasing complexity of ourcontrol systems and under the pressure ofstaff reduction, commercial solutions arebecoming an alternative choice (PLCs,SCADA,LabView,FactoryLink,RtWorks, Vsystem, etc.) to in-housedevelopment. They can do a good fractionof the tasks required and can in general beeasily interfaced to custom specificsolutions. This feature is essential tointroduce them into existing environments.

SystemRequirementsw

vieRewvie

Re

Architectural
DesignDetailed
DesignstTe

Transfer

Basic PSS-05 Development ModelstTe

Operation &MaintenanceThey are cost-effective, despite the high initial investment.
Software Sharing
Software sharing and collaborative efforts are getting stronger. One could get the impression that the times ofcompetition inside and between research laboratories are over. Many initiatives inside and between labs ( for example
CERN-ESRF, CERN-GSI, EPICS) have been started to join forces. At CERN a controls group for experiments has
been set up and a controls board co-ordinates the activities between five controls groups (accelerator, experiments,infrastructure). The Software Sharing (SOSH) initiative goes even further. EPICS deserves a few extra words since it
was one of the dominating topics of the conference. It has come to its present popularity thanks to impressive
collaborative efforts put into the development. Due to the ongoing commitment of major laboratories, it has asteadily growing number of users, and industry is becoming interested as well. If it were available under LynxOs, itwould find its way into European institutes faster.
Communications
In the area communications the de facto standard is TCP/IP. Is OSI dead? Fieldbuses do not seem to be an issue
anymore, but fast data-links for high throughput demand are coming to the fore. With the WWW growing rapidly,
we find WebServers with direct links to controls applications. Virtual reality is on the horizon of controls.

CONCLUSIONS
Let me conclude by addressing some organizational aspects of the conference. The usual and again unansweredquestion came up, if there was enough time for discussions. The participants were split roughly 50-50 on having
parallel sessions or not. Some topics could have been shortened.
Being right in the center of the beautiful city of Chicago contributed to the attraction of the conference. Apart fromthe flat lecture hall, the location and accommodations were a real pleasure. The computing facilities with the efficientand friendly support staff have set a high mark, a real challenge for the organizers of the next conference. During thetours to Argonne and Fermilab the application of controls was demonstrated and we had a glance at future in theVirtual Reality Cave. One of the highlights was our VIP visit to the Monet exhibition, which by itself would havebeen reason enough to come to Chicago. The banquet was another occasion to admire the good organization. Thanks
also to those I forgot, which usually happens to me.
Last, but not least, I would like to express our warmest thanks to Peter Lucas and his superb team, who madeICALEPCS ‘95 an unforgettable event.