Serial Highway Research Articles

Data acquisition and analysis system for the TPE-RX reversed-field pinch

Data acquisition and analysis systems for a reversed-field pinch (RFP) machine, the toroidal pinch experiment (RX) [TPE-RX, R/a=1.72/0.45 m, Ip<1 MA (designed)], are presented. Many kinds of diagnostic systems are installed on TPE-RX, and 392 signal channels at maximum from the diagnostic systems are routinely acquired by using the Computer Automated Measurement and Control system. The data are acquired through a serial highway into a front-end computer. A custom made, special computer program system, called DAQR, has been developed for the data acquisition routine. Software libraries are also developed for the data analyses of the plasma parameters, perturbed mode structures of the RFP plasma, and radiation from plasma.

Recent changes of JT-60 data processing system

The JT-60 data processing system is a large computer complex, gradually being modernized by utilizing progressing computer and network technologies. There were three major changes in our system recently. A VME-based fast data acquisition system (FDS) has been developed to enlarge a transient mass-data storage system (TMDS). It can acquire the data of 6 MB per channel with 1 or 5 μs sampling. Now there are three FDSs with 29 channels. The TMDS, which was composed of a mini-computer and 61 channels of 6 MB memory modules with 5-μs sampling, has been replaced with a new system based on the technology of the VME-based fast data acquisition system. One of the outdated auxiliary crate controllers with micro-processor (ACM), which controls CAMAC modules in the crate on the serial highway, acquires data from them and transfers data to the main computer, has been replaced by a workstation with a VMEbus byte-serial highway driver. The combination of a workstation and a VMEbus byte-serial highway driver has been developed and used to replace many mini-computers in our system. A workstation with a digital linear tape (DLT) library has been introduced as final data storage. The conversion of a few terabytes of raw data tapes for a cartridge tape library (CTL), which is attached to a mainframe computer, Fujitsu GS8300, will be started by using data conversion software prepared to handle mainframe data on the workstation.

A new CAMAC and VXIbus high performance highway interconnect

High performance, distributed data acquisition and control systems based on the CAMAC Serial Highway have been used extensively in the nuclear science field for 20 years. The need for higher I/O system throughput and the increased use of VXIbus-based instrumentation has led to the development of a new highway interconnect. This interconnect supports CAMAC crates, VXI chassis or a mixture of CAMAC and VXI on a high-speed fiber-optic highway. A typical highway interconnect system consists of a VMEbus or PCI bus host interface card, a fiber-optic ring configuration, CAMAC crate controllers and/or VXI Slot-0 controllers. The development of a VME-based I/O controller is being considered. Various throughput benchmarks and initial field experience are discussed. The crate controller supports the FASTCAMAC protocol being proposed to the NIM Committee. The maximum I/O throughput in FASTCAMAC mode is 10 megabytes/s.

The CEBAF accelerator control system: migrating from a TACL to an EPICS based system

CEBAF is in the process of migrating its accelerator and experimental hall control systems to one based upon EPICS, a control system toolkit developed by a collaboration among several DOE laboratories in the US. The new system design interfaces existing CAMAC hardware via a CAMAC serial highway to VME-based I/O controllers running the EPICS software; future additions and upgrades will for the most part go directly into VME. The decision to use EPICS followed difficulties in scaling the CEBAF-developed TACL system to full machine operation. TACL and EPICS share many design concepts, facilitating the conversion of software from one toolkit to the other. In particular, each supports graphical entry of algorithms built up from modular code, graphical displays with a display editor, and a client-server architecture with name-based I/O. During the migration, TACL and EPICS will interoperate through a socket-based I/O gateway. As part of a collaboration with other laboratories, CEBAF will add relational database support for system management and high level applications support. Initial experience with EPICS is presented, along with a plan for the full migration which is expected to be finished next year.

The NSC 16 MV tandem accelerator control system

The computerized control system for the 16 MV Pelletron accelerator at the Nuclear Science Centre runs on a PC-AT 386 computer. Devices in the accelerator are interfaced to the computer by using a CAMAC Serial Highway. The software, written in C, is Database oriented and supports many features useful for the accelerator operation. The control console consists of an EGA monitor, keyboard, assignable control knobs and meters, a diagrammatic display showing the overall status of the machine and a similar panel for showing the status of radiation safety interlocks. The system has been operational for the past three years and is discussed below.

HT-7 machine control system

The paper deals with the design and implementation of the machine control system for the HT-7 tokamak, at present under construction in Hefei, China. This is a distributed system which achieves a balance between performance and cost. A powerful UNIX workstation with a CAMAC serial highway serves as the system supervisor. Man-machine interface is based on the industry standard X Window system. Programmable logical controllers are used for subsystems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Control System of RIKEN Heavy Ion Accelerator Complex

The RIKEN heavy ion accelerator complex is controlled by means of three minicomputers, which are linked with one another through optical fiber networks. CAMAC serial highway and GP-IB are used for the link with accelerator devices. Two types of intelligent modules are developed for the interface to devices; one is a CAMAC module and the other is a control module for high-speed local control of the accelerator devices. The operating system is a combination of a real-time and a UNIX system. Application programs are written in FORTRAN 77 language. A color display-based operator's console is adopted with the aim of simple operation and flexibility for future modification and expansion.

MTX data acquisition and analysis computer network

For the MTX experiment, we use a network of computers for plasma diagnostic data acquisition and analysis. This multivendor network employs VMS, UNIX, and BASIC based computers connected in a local area Ethernet network. Some of the data is acquired directly into a VAX/VMS computer cluster over a fiber-optic serial CAMAC highway. Several HP-Unix workstations and HP-BASIC instrument control computers acquire and analyze data for the more data intensive or specialized diagnostics. The VAX/VMS system is used for global analysis of the data and serves as the central data archiving and retrieval manager. Shot synchronization and control of data flow are implemented by task-to-task message passing using our interprocess communication system. The system has been in operation during our initial MTX tokamak and FEL experiments; it has operated reliably with data rates typically in the range of 5 Mbytes/shot without limiting the experimental shot rate.

The sandia ion beam — A high heat flux testing facility

The Sandia Ion Beam Test System is used to conduct high heat flux tests of full scale components for fusion experiments. Heat fluxes of more than 4 kW/cm2 have been achieved with a hydrogen ion beam. The ion beam 22 cm grid set provides an adjustable width Gaussian heat flux profile which can be focused to a full width at half maximum of 13 cm. Diagnostics include an imaging radiometer, two-color pyrometers, thermocouples, strain gauges, water calorimetry, as well as surface and metallographic analysis systems. A versatile sample cooling loop provides up to 32 l/s of water at pressures up to 6.9 MPa and temperatures up to 280 °C. The pH and oxygen content of the sample cooling water can also be controlled. A large target chamber allows targets of 1 m2 and can be separately vented for target exchange without reconditioning the ion beam grid set. An RF induction ion source allows precise beam power and perveance control for different target testing requirements. Computer control is employed through a CAMAC serial highway with a menu driven operator interface. High heat flux tests have been conducted for JET, DIII-D, and CIT. Results from these tests will be shown as examples of current high heat flux testing activities.

Data-acquisition system of the reversed field pinch device REPUTE-1

The new, compact data-acquisition system of the reversed field pinch device, REPUTE-1, is reported. Its distinctive feature is high flexibility and easy handling. The interface between the computer and measurement devices is CAMAC. The computer and the CAMAC devices are connected to a CAMAC byte serial highway that transmits setup parameters and acquisition data. The computer carries out setup of CAMAC devices and data acquisition automatically by use of CAMAC parameters and the acquisition data base. The maintenance tools for the data base are also provided. The computer system, which consists of a ‘‘TOSBAC DS-600,’’ has been in operation for REPUTE-1 since 1985.

ＪＦＴ‐２Ｍトカマクにおけるデータ処理システムの開発

Data acquisition system for JFT-2M tokamak has been developed. It systematically handles many types of data; monitoring data of JFT-2M tokamak machine, power supplies, plasma control system, several heating apparatus and a variety of data measured with diagnostic instruments. The system consists of a main super mini-computer, a front-end mini-computer and two CAMAC serial highways. This layered configuration assures its high reliability because of distributing definitely-defined processing functions to each layer. The software of this system is characterized by good man-machine interface and the flexible extention as well as processing speed and good maintainability. In the tokamak experiment, the system can process about 1.5 Mbyte data during the discharge interval of 3.5 min.

New Developments in the Computer Complex System for the JFT-2M Tokamak

The JFT-2M computer complex system of the Japan Atomic Energy Research Institute (JAERI) consists of a data acquisition system and a plasma control system. The data acquisition system is composed of a CAMAC serial highway, a front-end minicomputer, a super-minicomputer and their peripherals. The system constitutes a definite hierarchical structure. This provides for easy expansion and maintenance as well as for improved RAS (reliability, availability and serviceability) functions and man-machine interface capabilities. The system permits unified control and high quality analysis of experimental data from the JFT-2M tokamak, processing 1.2 megabytes of data in less than 3 minutes. The plasma control system is made up of a pre-programmed minicomputer for current form pattern generation, an analog computer for high-speed plasma control, a local data logger, and thyristor power supplies. This system controls poloidal coil current by real-time feedback method. With a learning control function added to it, the system can effectively correct steady-state deviations.

A CAMAC System Controlled by an IBM at Computer for Time-Resolved Spectroscopy

An IBM AT computer interfaced to a small CAMAC system offers considerable power without the complexity and expense of a large general-purpose system. Our system for time-resolved spectroscopy features menu-driven FORTRAN-based software; high-resolution and high-speed (8K channels, 5-μs fixed dead time) ADCs; segmentable histogram memories (24-bit counts) with large memory space for many histogram segments; independently variable separate histogram dwell times; remote control via a CAMAC serial highway; and ground isolation between the data acquisition equipment and control computer by means of fiber optics.

New High-Performance Computer Interfaces to CAMAC

Data acquisition and control systems have often included the need for high throughput between the front-end hardware and the host computer. This is particularly true in the aerospace/defense and experimental physics fields. With the advent of more sophisticated I/O hardware and faster host computers with larger memories, the need for higher performance real-time computer interfaces has increased dramatically. A family of CAMAC-based interface products has been developed that supports high data throughput while providing the flexibility to meet the particular application. These new products fall into three basic categories: enhancements to the CAMAC Serial Highway, new CAMAC crate controllers, and software drivers. The Serial Highway enhancements provide at least a five-fold improvement in effective throughput and rival the Parallel Branch Highway in that regard. A new crate controller with a ribbon-cable bus interface uses balanced-line transmission and supports a bus length to 500 feet. List processing is provided as a hardware option for the Serial Highway Driver and is supported by a list sequencer module, an auxiliary crate controller, as well as software device drivers. This paper describes these new products, details their performance, and recommends trade-offs for their application. Benchmark comparisons indicate the extremely high data throughput that has been obtained. With certain configurations, Serial Highway throughput approaching three megabytes per second can be achieved.

An Ultrahigh Speed CAMAC Interface for a Large Flight Simulator System

The real-time simulation subsystem (RTSS) at the NASA Langley Research Center in Hampton, VA, consists of several CDC CYBER computers and over 20 flight simulation sites. This simulation network is used by the Langley Center to advance the state of aeronautics and to improve air safety. The current simulator interface system at NASA-Langley was installed in 1968 and uses centrally located analog and discrete conversion equipment. Of the alternatives studied by NASA for a replacement RTSS, only the network and input/output (I/O) system conforming to the international computer automated measurement and control (CAMAC) standards meets their requirements. The CAMAC serial highway provides a distributed I/O system with an extremely high data throughput approaching 24 000 000 information bits/per second. Fiber-optic links transmit the data over paths to 1 km. For multisite simulations, a computer-controlled electronic switch configures site highways in any combination. The CAMAC system uses analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and synchro converters with 16 bits of resolution to give the needed system performance. The time to acquire data from 80 16-bit ADCs and 960 discrete inputs and transfer them to the CYBER central memory is less than 320 ?s. Similarly, the time from CYBER central memory to the setting of 256 16-bit DACs and 960 discrete outputs is less than 650 ?s.

Computer control and data-acquisition system for the rf test facility

The radio frequency test facility (RFTF) at Oak Ridge National Laboratory, used to test and evaluate high-power ion cyclotron resonance heating (ICRH) systems and components, is monitored and controlled by a multicomponent computer system. This data-acquisition and control system consists of three major hardware elements: (1) an Allen-Bradley PLC-3 programmable controller, (2) a VAX 11/780 computer, and (3) a CAMAC serial highway interface. Operating in LOCAL as well as REMOTE mode, the programmable logic controller (PLC) performs all the control functions of the test facility. The VAX computer acts as the operator’s interface to the test facility by providing color mimic panel displays and allowing input via a trackball device. The VAX also provides archiving of trend data acquired by the PLC. Communications between the PLC and the VAX are via the CAMAC serial highway. Details of the hardware, software, and the operation of the system are presented in this paper.

The ORNL 25 MV tandem accelerator control system

The CAMAC-based control system for the 25 MV tandem electrostatic accelerator of the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory (ORNL) was specified by ORNL and built by the National Electrostatics Corporation. Two Perkin-Elmer 32-bit minicomputers are used in the system: a message switching computer and a supervisory computer. The message switching computer transmits and receives control information on six serial highways. This computer shares memory with the supervisory computer. Operator consoles are located on a serial highway; control is by means of a console CRT, trackball, and assignable shaft encoders and meters. Two identical consoles operate simultaneously: one is located in the tandem control room; the other is located in the cyclotron control room to facilitate operation during injection of tandem beams into the cyclotron or when beam lines under control of the cyclotron control system are used. The supervisory computer is used for accelerator parameter setup calculations, actual accelerator setup for new beams based on scaled, recorded parameters from previously run beams, and various other functions. The experience of nearly seven years of control system operation and improvements is 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.

A CAMAC based system for an electromagnetic isotope separator

Considering the new emplacement of the isotope separator close to the 20 UD tandem, an entirely new control and monitoring system was conceived. The system is built around a CAMAC serial highway driven by a microprocessor based crate controller developed in our laboratory. Because the ion source and its power supplies are at a 100 kV off ground potential, a fiber optic link is used for the serial highway. At the control console a TV monitor and a light pen allow the assignment of four parameters to a set of two meters and two knobs. The hardware and software organization of the system is described together with the technique used in spark protection for CAMAC modules and associated circuitry.

The safety interlock system for the Chalk River tandem accelerator superconducting cyclotron (TASCC) facility

The Chalk River TASCC Facility consists of a 13 MV tandem accelerator injecting into a K = 520( ME q 2 ) superconducting cyclotron. A microcomputer-based safety interlock system is used to monitor a variety of hazards and automatically initiate protective actions based on the monitored information. Inputs to and outputs from the system are handled by remote stations that communicate with the control room via a serial highway. Information on all monitored hazards is displayed in the control room on a colour video terminal; the path of the beam and radiation levels are displayed on a large plan view of the TASCC Facility. Several smaller displays are located around the Facility.