Integrating the Latest Technologies into a Java Process Control MMI

The LHC/IAS (equipment control) Group is developing supervisory systems by means of industrial SCADA packages. For the past four years, we have provided Web remote access to the data coming from our supervisory and control systems. Combining our findings, an architecture and a strategy have been set-up for a generic Java interface which offers a remote and unique access to all kinds of control data. Using the object-oriented technology, the architecture dissociates the data access layer from the presentation one. Thus, the interface may be used to access different types of data. The data are stored in the interface together with a set of related information (acquisition date, unit, etc.). The graphical interface is based on components which may be stored independently and which can be accessed on demand. Attention has been given to easing the integration of commercial components. To help non-specialists in creating components, a graphical scripting language has been developed

From a UNIX to a PC Based SCADA System

In order to facilitate the development of supervisory applications involved in slow process control (such as cryogenic control), the LHC/IAS Group (Equipment Controls Group) opted, a few years ago, for an industrial SCADA package which runs on UNIXÒ platforms. However, to reduce costs and following market trends, it has been decided to move over to a PC-based package. Several processes relating to the testing of the prototypes of the LHC magnets are already controlled in this way. However, it was still necessary to provide all the services previously available to the users, for example, data archiving in central databases, real-time access through the Web, automatic GSM calls, etc. This paper presents the advantages and drawbacks of a PC-based package versus a Unix-based system. It also lists the criteria used in the market survey to arrive at the final selection, as well as, the overall architecture, highlighting the developments needed to integrate the package into the global computing environment

Experiments and cycling at the LHC prototype helf-cell

The first version of the LHC prototype half-cell has been in operation since February 1995. It consists of one quadrupole and three 10-m twin aperture dipole magnets which operate at 1.8 K. This experimental set-up has been used to observe and study phenomena which appear when the systems are assembled in one unit and influence one another. The 18-month long experimental program has validated the cryogenic system and yielded a number of results on cryogenic instrumentation, magnet protection and vacuum in particular under non-standard operating conditions. The program was recently complemented by the cycling experiment: it consisted in powering the magnets following the ramp rates which will be experienced by the magnets during an LHC acceleration. In order to simulate 10 years of routine operation of LHC, more than 2000 1-hour cycles were performed interleaved with provoked quenches. The objective of this experiment was to reveal eventual flaws in the design of components. The prototype half-cell performed to expectations showing no sign of failure of fatigue of components for more than 2000 cycles until one of the dipoles started exhibiting an erratic quench behavior

The LHC test string: first operational experience

CERN operates the first version of the LHC Test String which consists of one quadrupole and three 10-m twin aperture dipole magnets. An experimental programme aiming at the validation of the LHC systems started in February 1995. During this programme the string has been powered 100 times 35 of which at 12.4 kA or above. The experiments have yielded a number of results some of which, like quench recovery for cryogenics, have modified the design of subsystems of LHC. Others, like controlled helium leaks in the cold bore and quench propagation bewteen magnets, have given a better understanding on the evolution of the phenomena inside a string of superconducting magnets cooled at superfluid helium temperatures. Following the experimental programme, the string will be powered up and powered down in one hour cycles as a fatigue test of the structure thus simulating 20 years of operation of LHC

Structuration et exploitation numerique des informations geographiques

SIGLECNRS TD 18023 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc