Text Box: being triggered! This is of course due largely to the size of the site, but also to the fact that the LHC is again in a building phase. “99% of the alarms now relate to tests, exercises or new adjustments”, the person in charge of the firemen points out. It is therefore all down to the remaining 1%; for that the 53 firemen - from all European countries - stay in readiness all of the time. “If an incident proves to be real a menu for intervention is published immediately.” The intervention menus take the drawing of the particular zone, on which the access and evacuation routes are shown plus the various precautions to take before entering that zone. Facilities and equipment vary from one site to another and from one building to another. The firemen are trained for all Come back to our Website

INDUSTRIAL SUPERVISION

Dynamic supervision for alarm management at CERN

Text Box: Undertaking a project with CERN, the European laboratory for particle physics, involves some small contribution to scientific progress. There is also a window effect: each installed application creates visibility. For ARC Informatique, whose supervisory software Spie selected for the new alarm management system on the CERN site, a third element emerged: that of addressing technical challenges and including them as standard in subsequent versions of PcVue. The challenge was to create an independent, secure, dynamic supervisory system site-wide for meeting the needs of scientists and technical personnel alike. Text Box: CERN’s supervisory alarm system, designed and installed by Spie, is based on ARC Informatique’s PcVue SCADA software. The aim is to supervise the infrastructure of the particle accelerators and ensure the security of staff and experimental material. The system handles over 300,000 variables in a fully redundant manner and manages 17,000 distributed alarms in 33 zones above and below ground. Spie engineers developed an interface for dynamic generation of the supervisory windows in PcVue, linked to CERN’s central databases. Text Box: Project Overview Text Box: Austrian developer ETM (recently acquired by Siemens), the team selected ARC Informatique’s PcVue SCADA software for its scalability in meeting the application criteria. The necessity of dynamic supervision It is not easy to install a supervisory system on a site as large and as complex as this, but the main difficulty arises from the continuous development that is taking place. “On the tens of square kilometres of the site, there are always staff constructing buildings, modifying wiring, adding sensors or conducting tests that simulate breakdowns,” declares Sylvain Damge, in charge of the Spie project. “In practice, these activities result in the addition or changing of some 500 to 1,000 sensors per month.” This will continue once the LHC ring becomes operational, as work on the next generation of particle accelerators proceeds. Rudolf Knoors, in charge of the local Spie office, explains, “With a classic industrial supervisory application, one would have considered working through the night. The availability levels required by the project specification ruled out that mode of working. If the central server is powered down a twenty minute period is required to start up again, which is far too long since the critical nature of the CERN application dictates no more than 100 minutes per year of downtime.” So it was necessary to set up a dynamic database and Text Box: The project to create the Large Hadron Collider (LHC) was approved in 1994 and is one of the most ambitious scientific projects of our time. With a 6 billion Euro budget, this is one of the largest and most complex scientific instruments in the world. The European Organization for Nuclear Research (better known as CERN) has been engaged in particle Text Box: research for over 50 years. For the first time Japan and the United States are associated with CERN as observers. All of the participants will rely on the results of experiments conducted in the LHC - which should be operational in May 2008 - to address some of the questions of modern physics. The researchers intend to improve their understanding of the elementary particles that make up matter and antimatter. By recreating the conditions near to those of the Big Bang, scientists hope to use the particle accelerator to recreate Big Bang scenarios and clarify the mystery surrounding the creation of the universe. The LHC is a ring 27km in circumference, which lies some 100m down below the Gex district and straddles the Franco-Swiss border. The construction period was less than that of its predecessor the Large Electron Positron Collider (LEP), as the LHC replaces it in the same tunnel. However, new requirements arose from a desire to extend the supervision of the experiments to the extreme and from CERN’s accession to the INB statute for fixed nuclear installations. With this background, the CSAM project (CERN Safety Alarm Monitoring) was created and the search began for a new supervisory tool. Located very near to CERN (in Saint-Genis-Pouilly, close to Geneva), Spie, an experienced supplier of complex technology services, invested in securing the tender. After considering PVSS software from the Text Box: Another aspect illustrating the dynamic nature of the application is the use of bilingual workstations. CERN employs scientists from all over Europe and the world. The default language is French, but screens can be switched at any time to display in English. The PcVue application had to comply with one of CERN’s major criteria – remote access. In fact it is to the CERN teams that we all owe the invention of the World Wide Web (with Internet addresses starting with "www"), which was created for sending the results of experiments to scientists all round the world. The LHC particle accelerator is installed in a tunnel almost 27km long situated under the Franco-Swiss border. Additional functionality has been developed to enable PcVue to meet the project specifications and comply with Safety Integrity Level 2 (SIL2) (by the IEC 61508 standard) for safe operation. "When the development company has to invest major resources for a project, the teams at ARC Informatique take this as an Text Box: increase the maximum number of variables handled by the software. With a close partnership between Spie and ARC Informatique, an innovative supervisory solution has been developed with the capability of being updated both dynamically and independently. Developers at Spie finalized a set of communication interfaces to the CERN central servers, enabling automatic generation of windows for the application. When any work is completed the application infrastructure developed by Spie is entered in an Oracle database and PcVue inputs that data to create mimics and database contents. The PcVue screens are taken from drawings of the premises and the associated computer data added: network topologies, sensor positions and evacuation procedures plus all mimics associated with experiments, their variables and associated states. CERN provided the drawings of the facilities as AutoCAD files; these are converted into Windows Metafile (WMF) format. PcVue object libraries are used to generate the dynamic objects. The Oracle database uses unique identifiers for version control. The database handles more than 300,000 variables. Although this number was initially at the upper limit Text Box: of software-based processing performance, a collaborative project with ARC Informatique’s engineers enabled the installation of devices to manage the ever growing volume of parameters. Text Box: opportunity to improve the product,” Alain Faisant, sales manager at ARC Informatique assures us. This puts into context the investment risk incurred. Working on this project gave us the opportunity to develop innovative functionality for the security and dynamic updating modules of the software system,. The new functionality has subsequently been integrated into the latest versions of PcVue software to benefit all of our customers." This is evidenced in a project for Paris Airports (ADP) who selected PcVue for the ability to generate windows directly from AutoCAD plans for a similar alarm management application (see Measures no. 763, March 2004). Since then, this functionality has been upgraded again and now, in addition to drawings, even AutoCAD objects can be imported by PcVue and converted to interactive objects without manual intervention. Secure alarm management Implementation of the LHC project required the construction of a control centre. Named CCC for ”CERN Control Centre” it was opened in March 2006. The purpose of this room is to centralize all of the supervisory terminals (linked to the particle acceleration processes) for CERN’s three accelerators and for the supervisory terminals for CSAM alarms. Each client station is dedicated to alarm monitoring and can retrieve a menu from the centre and zoom in to any of the 33 security zones of the site. The alarms are divided into four levels according to the severity of the associated event. Alarms of level 0 (white) correspond to basic information; alarms of level 1 (blue) convey more important information, requiring a technician's intervention the same day. Level 2 (yellow) corresponds to equipment alarms that require a technician's immediate intervention. Text Box: kinds of incidents, but must equip themselves in a particular way for each type of event: a fire, a spike of radioactivity, an escape of rare gas or cryogenic liquid, or perhaps flooding. Bear in mind that the facilities are underground and the risk of flooding is increased by their proximity to the Jura Mountains and Lake Geneva. It is estimated that if all of the lifting pumps installed in the tunnels failed, the facilities would be completely flooded within ten minutes! That is why an effective supervisory system needed. Redundancy throughout The supervisor is the keystone of the alarm system installed by Spie. For the integrator, a large part of the work centred on the design of the alarm display architecture. Spie engineers first tried to use the existing system as a basis for the new system. Existing alarm display panels have been retained. In the control centre and in the fire station, monitoring panels show a menu of the site on which there are simple LEDs (light emitting diodes) corresponding to the various facilities. But this system has reached its limits. The capacity to display information was insufficient for organizing a suitable response, with no traceability. This led to a rollout of a new network dedicated to alarms. Text Box: Finally level 3 (red) designates all alarms for the fire station. These include alarms triggered by a fire, gas escape, flooding, a broken elevator, a wounded person or use of a special line for the firemen, called the “red phone”. Overall there are around 17,000 alarms that can be sent to the control centre via a redundant central PLC, with around 64 PLCs across 33 zones and a pair of servers for picking up alarms. All alarms of level 3 are routinely sent to the CERN fire station and viewed on supervisory stations the same as those in the control centre. When visiting the firemen’s premises dedicated to supervision, one realizes how often alarms have to be dealt with: hardly ten minutes goes by without a level 3 alarm Text Box: “In the context of the CSAM project, a Gigabit redundant Ethernet network with two separate links has been installed,” stated Mr Damge. “One of the cables uses twisted copper wire pairs and the other uses fibre optic, which affords extra security in view of the wide variety of potential incidents.” This network links the CSAC (a redundant central PLC to manage the alarms) with the SAMC (the data acquisition servers). Text Box: It also links the existing PLCs in each of the 33 zones with those in the SAMC. All of CERN’s security zones have been equipped with two redundant PLCs to centralize the information from the various sensors (access control, state of machinery and processes, gas and fire detectors). Each PLC has 512 inputs and 256 outputs, connected by Wago terminal blocks. In each zone, Spie engineers installed Text Box: cabinets with touch panel PCs serving as PcVue clients. These provide the same functionality as the control unit stations, plus the option of operating some facilities in “degraded” mode (i.e. forced working despite there being an alarm). From these stations, the technicians have access to the “Safety Actions”. Using logical functions of “AND” and “OR”, the installers implemented the mimics and procedures with linkage to events (opening and closing of the firebreak bulkheads, setting the thresholds for raising alarms, etc.). This reduces system configuration time during the construction of buildings and extensions; the changes are available immediately across the entire suite of 46 workstations. Finally, some operator control panels have been added with direct links to the PLCs to retrieve sensor data for the building in case of breakdown of the central supervisor. Whilst the LHC is not expected to be fully operational before 2008, the alarm management system is already running. Everything is measured, published and archived, from the curves of gas detection in the buildings to the transmission time for alarms (time stamping). And all that is done to ensure faultless availability of the system. “We committed ourselves to an availability rate of over 99.98%” said Rudolf Knoors. “That represents a maximum downtime of 100 minutes in a year.” It is recognised that prolonged stoppage of the system for more than four hours would immediately trigger an ORSEC plan (Organization for Civil Defence Response) across the entire CERN area. Knowing this, one becomes aware of the need for a faultless supervisory system. Frédéric Parisot Industrial IT writer, Mesures journal