Atsuyoshi Akiyama

KEKB control system: the present and the future

Achievements of KEKB control system during the commissioning of KEKB accelerators are reported. The KEKB control system is the first major application of EPICS toolkit in JAPAN. We added some software components on the top of EPICS toolkit. One of these is the system to automate generation of the EPICS database configuration files using ORACLE database management system. Although it costs us a lot of effort to develop, this kind of configuration management system is essential for a large accelerator like KEKB. Another component is an implementation of EPICS CA (Channel Access) interface in the script languages. SAD, a modeling program with a scripting language capability, Python, an object oriented scripting language are currently supported in the KEKB control system. These scripting languages are used to develop high level applications, such as an orbit correction program with graphical user interface using Tk library. Combination of these scripting languages and EPICS CA provides flexibility in the control system. KEKB control system also includes some new hardware components, including Arcnet based magnet power supply controllers and VME single board computers based on Motorolas PowerPC750 CPU. The performance of these components will also be reported. The problems and (possible) solutions found during the KEKB commissioning are also discussed.

The TRISTAN control system

The 8 GeV accumulation ring and the 30 GeV main ring of TRISTAN, an accelerator-storage ring complex at KEK, are controlled by a highly computerized control system. Twenty-four minicomputers are linked by optical fiber cables to form an N-to-N token ring network. The transmission speed on the cables is 10 Mbps. From each minicomputer, a CAMAC serial highway extends to the controlled equipment. At present, twenty minicomputers are connected to the network and are used to control the accumulation ring. The software system is based on the NODAL language devised at the CERN SPS. The KEK NODAL system retains main features of the original NODAL: the interpretive scheme, the multi-computer programming facility, and the data-module concept. In addition, it has the following features: (1) fast execution due to the compiler-interpreter method, (2) a multi-computer file system (3), a full-screen editing facility, and (4) a dynamic linkage scheme for data modules and NODAL functions. The accelerators are operated through five operator consoles, each of which is managed by one minicomputer in the network. An operator console contains two 20-inch high-resolution color graphic displays, a pair of touch-panels, and ten small TV monitors. One touch-panel is used to select a program and a piece of equipment to be controlled; the other is used mainly to perform the console actions.

KEKB accelerator control system

The KEKB accelerator control system including a control computer system, a timing distribution system, and a safety control system are described. KEKB accelerators were installed in the same tunnel where the TRISTAN accelerator was. There were some constraints due to the reused equipment. The control system is based on Experimental Physics and Industrial Control System (EPICS). In order to reduce the cost and labor for constructing the KEKB control system, as many CAMAC modules as possible are used again. The guiding principles of the KEKB control computer system are as follows: use EPICS as the controls environment, provide a two-language system for developing application programs, use VMEbus as frontend computers as a consequence of EPICS, use standard buses, such as CAMAC, GPIB, VXIbus, ARCNET, RS-232 as field buses and use ergonomic equipment for operators and scientists. On the software side, interpretive Python and SAD languages are used for coding application programs. The purpose of the radiation safety system is to protect personnel from radiation hazards. It consists of an access control system and a beam interlock system. The access control system protects people from strong radiation inside the accelerator tunnel due to an intense beam, by controlling access to the beamline area. On the other hand, the beam interlock system prevents people from radiation exposure by interlocking the beam operation. For the convenience of accelerator operation and access control, the region covered by the safety system is divided into three major access control areas: the KEKB area, the PF-AR area, and the beam-transport (BT) area. The KEKB control system required a new timing system to match a low longitudinal acceptance due to a low-alpha machine. This timing system is based on a frequency divider/multiply technique and a digital delay technique. The RF frequency of the KEKB rings and that of the injector Linac are locked with a common divisor frequency. The common divisor frequency determines the injection timing. The RF bucket selection system is also described. r 2002 Elsevier Science B.V. All rights reserved.

KEK NODAL System

The KEK NODAL system, which is based on the NODAL devised at the CERN SPS, works on an optical-fiber token ring network of twenty-four minicomputers (Hitachi HIDIC 80s) to control the TRISTAN accelerator complex, now being constructed at KEK. KEK NODAL retains main features of the original NODAL: the interpreting scheme, the multi-computer programming facility, and the data-module concept. In addition, it has the following characteristics: (1) fast execution due to the compiler-interpreter method, (2) a multicomputer file system, (3) a full-screen editing facility, and (4) a dynamic linkage scheme of data modules and NODAL functions. The structure of the KEK NODAL system under PMS, a real-time multitasking operating system of HIDIC 80, is described; the NODAL file system is also explained.

Man-Machine Interface of Tristan

This report describes a console system which is the essence of man-machine interface used to operate TRISTAN. Ergonomic design and its implementation has been done in construction of the TRISTAN Central Control Room (TCCR) and Operators Console (OPC). The environment of the console is designed to minimize fatigue, eyestrain and discomfort by optimizing light fixtures, minimizing noises made by fans or footsteps and harmonizing colors and brightness throughout the control room. The OPC is composed of a special supervisory console at the center and five identical standard consoles. The difference between the two types is that hard-wired switches which manipulate beam gates and related equipments to assure the safety of personnel are mounted only on the former console. The safety system is based on the hardware techniques similar to those have been accepted for the control of critical industrial installations. Each of the consoles contains ten color TV monitors, two high resolution graphic display monitors and two touch-panels with color character display monitors. Each console is managed by a minicomputer of the TRISTAN control computer network. The graphic displays are connected directly to the computer. The touchpanels and the corresponding character video RAM modules are through CAMAC serial highway.

The rejuvenation status of TRISTAN accelerator control system

Abstract Ten years have passed since the current control system started the operation of the TRISTAN accelerator. The system uses CAMAC as a front-end electronics, and they are controlled by 25 Hitachi process computers linked by a N to N token ring network. In order to have the ability to perform complicated accelerator operations, there is a strong request to renew these 25 process computers. Firstly, we review how we will rejuvenate the current control system under some constraints, such as the lack of man-power, limited time and financing. This is followed by proposals for the next step of rejuvenation.

Characteristics of the TRISTAN control computer network

Abstract Twenty-four minicomputers forming an N -to- N token-ring network control the TRISTAN accelerator complex. The computers are linked by optical fiber cables with 10 Mbps transmission speed. The software system is based on NODAL, a multicomputer interpretive language developed at the CERN SPS. The high-level services offered to the users of the network are remote execution by the EXEC, EXEC-P and IMEX commands of NODAL and uniform file access throughout the system. The network software was designed to achieve the fast response of the EXEC command. The performance of the network is also reported. Tasks that overload the minicomputers are processed on the KEK central computers. One minicomputer in the network serves as a gateway to KEKNET, which connects the minicomputer network and the central computers. The communication with the central computers is managed within the framework of the KEK NODAL system. NODAL programs communicate with the central computers calling NODAL functions; functions for exchanging data between a data set on the central computers and a NODAL variable, submitting a batch job to the central computers, checking the status of the submitted job, etc. are prepared.

The Construction of the SuperKEKB Magnet Control System

There were more than 2500 magnet power supplies for KEKB storage rings and injection beam transport lines. For the remote control of such a large number of power supplies, we have developed the Power Supply Interface Controller Module (PSICM), which is plugged into each power supply. It has a microprocessor, ARCNET interface, trigger signal input interface, and parallel interface to the power supply. The PSICM is not only an interface card but also controls synchronous operation of the multiple power supplies with an arbitrary tracking curve. For SuperKEKB we have developed the upgraded version of the PSICM. It has the fully backward compatible interface to the power supply. The enhanced features includes high speed ARCNET communication and redundant trigger signals. Towards the phase 1 commissioning of SuperKEKB, the construction of the magnet control system is ongoing. First mass production of 1000 PSICMs has been completed and their installation is in progress. The construction status of the magnet control system is presented in this report. (1) Introduction ----Original PSICM KEKB, the asymmetric electron-positron collider for B-meson physics, started in operation in Dec.1998 and finished in Jun. 2010. KEKB control system was EPICS-based, using more than 100 VME/VxWorks computers as IOC (I/O Controller). About 2500 magnet power supplies were installed in the KEKB storage rings and the injection beam transport lines and controlled by 11 IOCs. To connect such many power supplies to the IOCs, we adopted ARCNET as the field bus and developed the PSICM (Power Supply Interface Controller Module). . Original PSICM New PSICM Microprocessor AM186 MPC8306 Clock frequency 20MHz 133MHz Data memory 256kB SRAM 128MB DDR2 SDRAM Program memory 256kB EPROM 64MBit NOR FLASH ARCNET interface 2.5Mbps Backplane mode 2.5Mbps/5Mbps/10Mbps Backplane mode Controller COM20020 COM20022 Media driver HYC2485 HYC5000 Power required 5V 0.4A 5V 1A ARCNET Interface board (4 ch. / boards)