Control, Data Access And Communication Research Articles

The Design and Implementation of the Remote Control and Visualization System for Pulse Application Experiments

In order to meet the needs of pulse experiments in different environments, a remote control and visualization system (RCVS) is designed and implemented based on the conceptual design of COntrol, Data Access and Communication (CODAC). RCVS works on the web server and adopts the website deployment mode of LAMP (Linux + Apache + MySQL + PHP/Python) and the working mode of B/S architecture. It includes a remote data acquisition module, a remote real-time visualization module, a monitoring module, and a remote data access module. In the first one, to avoid system deadlock and other problems caused by concurrent operations between local and remote users and concurrent scheduling conflicts between remote users, we have improved the previous solution and adopted the Deterministic Finite Automaton (DFA) and the Two-Phase Locking (2PL) protocol to unify the state of RCVS and that of the overall system and to ensure the serializability of concurrent operations. With regard to real-time data visualization, RCVS adopts the technology of server push to obtain the needed data to minimize the pressure on the server and shun some problems such as server paralysis caused by network congestion in the case of large-scale concurrent request. In addition, RCVS provides a monitoring method based on a heartbeat mechanism and an Application Programming Interface (API) of the web end of the MDSplus database for system status monitoring and remote data retrieval and analysis. Moreover, thanks to the responsive design and the deployment model of B/S architecture, the system can be accessed on any terminal device. This system as part of the overall experimental system will be integrated into the Experimental Advanced Superconducting Tokamak (EAST) neutral beam injection master control system in the future and provide services of remote control and visualization for its long-pulse experiments.

Conceptual design of the COMPASS-U control systems

The COMPASS-U tokamak is an advanced and more complicated successor of the COMPASS tokamak. Almost all main technological parts will be different. Both the higher performance of COMPASS-U and the increased number of parts and systems lead to a higher risk of failure. Therefore, new control systems must be developed regarding handling dangerous situations and integrating new systems. The COMPASS-U also opens the opportunity to make significant changes in the current systems based on the experience gained from COMPASS operation and to upgrade the systems to nowadays technologies.This article focuses on the conceptual design of the COMPASS-U control systems. It shows all CODAC (Control, Data Access, and Communication) systems their purpose, functionality, operation principle, interaction, and main used technologies.The COMPASS-U will use EPICS (Experimental Physics and Industrial Control System) for Slow control and supervision system. The real-time plasma control system will utilize MARTe2 (Multi-threaded Application Real-Time executor). The base control loop period of the Real-time plasma control system will be 50 μs as of COMPASS.

Progress of the control system for negative ion source based neutral beam injector prototype at ASIPP

The negative ion source based neutral beam injector (NNBI) will play an important role in Comprehensive Research fAcility for Fusion Technology (CRAFT). In order to explore the physics and engineering issues for NNBI, the RF negative ion based test facility has been tested with cesium seeding, negative ion production, and extraction at Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). According to the architecture of ITER CODAC (Control, Data Access and Communication) system and the experimental requirements of negative ion test facility, the control system for negative ion source based neutral beam injector prototype has been developed. It fulfills the physics experimental requirements, and what's more, it accumulates design experience for control system of CRAFT NNBI. In this paper, the control and data acquisition system are described, especially the real-time control, plant units interface and central control program. In the data acquisition section, the requirements are presented not only for the system, but also an improvement plan is given. Meanwhile, the interlock system is also present, including system architecture design and classification of interlock signals.

The redesign and implementation of data acquisition and control system for EAST NBI

The current data acquisition and control system (DACS) has been redesigned and upgraded according to the perspective of the ITER control data access and communication (CODAC) system to meet the requirements of further experiments and solve the underlying problems of the previous system. To maximize the load balancing of the system, the hot standby dual computer has been employed in the server control system (SCS) to accomplish computational tasks, complete data processing and storage and ensure steady operation of the system. Besides, the network control platform (NCP) will be built on the SCS to provide remote services, making system management more convenient. The new architecture not only corrects the defects of the existing system but also further explores the architecture design of the server cluster for processing the scientific experimental data.

From tore Supra to WEST: Evolution of the CODAC infrastructure

In 2013 Tore Supra limiter tokamak at CEA Cadarache went through major changes to become the WEST tokamak (Tungsten [W] Environment in Steady state Tokamak). The tokamak was upgraded into an X point divertor device. Taking advantage of its long discharge capability, WEST's goal is to minimize technological and operational risks of the actively cooled tungsten divertor for ITER.At the same time, Control Data Access and Communication (CODAC) system has been redesigned in order to satisfy the performance and evolutions needed by researchers, and to facilitate maintenance and evolution for the CODAC team.This paper describes the upgrade of the CODAC system from Tore Supra to WEST.

Digital filter polychromator for Thomson scattering applications

The paper describes the digital filter polychromator developed for Thomson scattering (TS) diagnostics. The device having ultra-low noise, high-speed detection system and up to 7 spectral channels is equipped with digitizer and single board computer for system control and data processing. The data acquisition system is capable to detect very short laser pulses of few ns width with low magnitude. This feature opens up new possibilities for the TS diagnostics design in modern fusion devices, which includes: operation with high background illumination, measurement of very low electron temperature and density at the plasma edge and scrape-off layer (SOL), separation of the TS signal and the stray light coming with a delay of several ns. The analysis of the TS signal waveform also gives a possibility to distinguish the TS and Mie scattering from the dust particles that is important for measurements in SOL. Owing to compactness and ultra-low energy consumption both optical and data processing units interfaced with optical Gigabit Ethernet were combined in a stand-alone device. Such all-in-one design with optical fiber input and optical digital output provides enhanced resistance to electromagnetic disturbances and simplify operation. A set of such polychromators can be mounted in a standard 19” rack and can be integrated with outer CODAC (Control, Data Access and Communication) system. Testing of the polychromators at the Globus-M2 tokamak has shown excellent performance of the developed serial devices.

Preliminary Design of ITER Divertor Langmuir Probe System

The primary aim of the ITER divertor Langmuir probe system is to measure the plasma parameters at the divertor target plates. Saturation ion flux coming from the direct-current biased probe mode is used for advanced machine control, and the swept double-probe mode is recommended to measure electron temperature and density for physics studies. The design of the probe system includes three parts. First, tungsten Langmuir probes are mounted on the side of the target plates for collecting current from plasma, and thermomechanical simulation results show the design of the probe is robust and can survive under harsh working environments. Second, the electronics consists of the power supply, mode switching, and signal conditioning box and is used for driving Langmuir probes in different operation modes to obtain expected plasma information. Third, the functions of instrument and control include publishing configuration; monitoring and control; calibration; data acquisition; communication with the control, data access and communication (CODAC) system; and real-time ion flux measurement at the divertor target. The system design also complies with ITER’s technical practices, standards, and codes.

Control and Diagnostic System for CFETR CSMC Testing Platform

The central solenoid model coil (CSMC) of the China Fusion Engineering Testing Reactor (CFETR) is currently in the manufacturing phase. Once completed, the CSMC will be tested on a testing platform. The testing platform is composed of several subsystems, which are coordinated by a control system to conduct a successful experiment and collect scientific data generated during the experiments. A diagnostic system is employed for the purpose of monitoring the status of a superconducting magnet and triggers the alarm system if an abnormal signal has been detected. The central control system of the CSMC testing platform is called the control data access and communication (CODAC) system. In order to realize the normal data communication between the CODAC system and a subsystem, an experimental physics and industrial control system (EPICS) Channel Access (CA) protocol is needed.

Preliminary design of I&C for ITER radial X-ray camera system based on CODAC

The Radial X-ray Camera (RXC), as an important diagnostic system among more than one hundred ones in ITER Tokamak, is used to measure the poloidal profile of plasma X-ray emission with high spatial and temporal resolution. The automatic and safe operation of RXC will require a reliable and rugged Instrumentation and Control (I&C) system which is used to monitor and control, acquire and process data and design operation procedures. The I&C has been preliminarily designed based on ITER CODAC (COntrol, Data Access and Communication) architecture and ITER-PCDH (Plant Control Design Handbook) Journeaux, [1] guidelines since the technical understanding of CODAC technology was helpful in development of plant system I&C for RXC.The monitor and the control functions, which were implemented by Slow Controller (SC) using PLC (Programmable Logic Controller), manage the slow signals such as status of various sensors, parameters of amplifiers, temperature of detectors and health status of cubicle. Data acquisition and data processing, which were realized by Fast Controller (FC) utilizing EPICS (Experimental Physics and Industrial Control System), are responsible for collection of raw signal from detectors, data archiving, data calculation through algorithmic and publishing to PCS (Plasma Control System). A state machine was developed to coordinate the execution of operation steps of RXC. The prototype I&C system for RXC was successfully tested on Mini−CODAC.

The ITER CODAC network design

The ITER CODAC (Control, Data Access and Communication) system is the conventional central control system responsible for operating the ITER facility. CODAC Networks comprise Plant Operation Network (PON), Time Communication Network (TCN), Synchronous Databus Network (SDN) and Data Archiving Network (DAN). CODAC networks connect all plant systems to the central control system through one or more networks depending on the requirements of the plant system I&Cs. The CODAC network infrastructure has been defined including network topology, backbone cable and space allocation network equipment in different ITER plant buildings.This paper presents the design of the current network infrastructure and the four functional networks. This paper also presents the implementation plan of the CODAC network according to the ITER project schedule.

New control systems at KSTAR compatible with ITER standard technologies

Through the lessons learned during the ITER control, data access and communication (CODAC) tasks and the interaction with various domestic and overseas communities, the KSTAR control system is being improved with new functions. We have adopted ITER synchronous data bus network (SDN) and time communication network (TCN) to increase the flexibility of control system design and improve system performance. Absolute time-based discharge operations and high-speed data communication interfaces are standardized as KSTAR standard software components. We used the reconfigurable I/O (RIO) library provided by CODAC for the renovation of a fast interlock system, and effectively implemented a real-time core structure through ITER for the next generation real-time control systems. A new hardware platform standard has been adopted for system standardization and convenience of maintenance international collaboration.

Multiple Fast Controller Synchronization for ITER Control System Model

ITER control system model (ICM) is a currently developed simulation platform for control, data access, and communication (CODAC), which is a central control system responsible for integrating and controlling all plant systems of ITER. ICM is a large-scale implementation of CODAC that follows hardware and software standards but does not have any interfaces to other physical components of ITER. ICM will serve as an excellent test environment for performance and scalability of upcoming plant system modules and new releases of CODAC software. This paper focuses on performance and reliability of the real-time components of ICM, consisting of eight fast controllers connected over physical networks and their dedicated high-performance switches. Two crucial ITER requirements are satisfied with 12.4- $\mu \text{s}$ 1-kB packet transfer latency and system clock synchronization with a standard deviation as low as 16.7 ns. This performance evaluation is required for demonstrating the reliability of the CODAC infrastructure and gathering important data for considering future plant system modules.

Development of Data Acquisition and Control System for Long Pulse Operations of Indian Test Facility of ITER DNB

The Indian test facility (INTF) is a negative hydrogen ion-based 100-kV, 60-A, 5-Hz modulated neutral beam injector system having a 3 s on/20 s off duty cycle. The prime objective of the facility is to characterize the ITER diagnostic neutral beam (DNB) with full specifications prior to shipment and installation in ITER. The automated and safe operation of the system will require a reliable and rugged instrumentation and control system that provides control, data acquisition (DAQ), safety, and interlock functions, referred to as INTF-DAQ and control system (DACS). The INTF-DACS has been designed based on the ITER Control, Data Access and Communication (CODAC) architecture and ITER-plant control design handbook guidelines to develop a technical understanding of the CODAC framework to be utilized for the development of plant system instrumentation and control for DNB. The hardware has been selected from the ITER slow-and-fast controller catalog. For high-speed diagnostics, non-National Instruments (NI) high-speed digitizers have been selected. In the area of software, the CODAC core software for control application and NI-LabVIEW for the DAQ application have been finalized. There are around 300 control and 500 acquisition channels consisting of thermal, optical, current, and voltage measurements. The DACS has the mandate to operate INTF for pulselengths up to 3600 s by integrating 14 different plant systems, which includes the power supply plant system under a separate controller. The corresponding development possesses many technical challenges. The estimated file size of a single experimental pulse is in GBs for which the ITER suggested HDF5 format is selected. The timing distribution is another challenge because of the different resolutions required in fast controller, slow controller, and high-speed diagnostics in a distributed area. Long pulse DAQ and monitoring is another challenge. Data exchange across the software platforms, based on Experimental Physics and Industrial Control System (EPICS) and LabVIEW, is also required for integration. At present, the control and DAQ hardware have been integrated and the development phase has been initiated on actual hardware platforms. This paper describes the various developmental activities undertaken to solve the technical challenges in the previously mentioned areas and integration of various components of the DACS toward realizing the full-fledged functional INTF DACS.

Integration of EPICS based monitoring for ion cyclotron high voltage power supply

A Dual output (27kV & 15kV), 3MW Ion Cyclotron High Voltage Power Supply (IC-HVPS) has been installed and integrated with a Diacrode based RF source to be used for ICRF (Ion Cyclotron RF) system. The IC-HVPS Controller is based on LabVIEW Real-time PXI controller, which supports all control and monitoring operations of the PSM based power supply. The controller supports all essential features like, fast dynamics, low ripple and protection for source and loads.EPICS (Experimental Physics and Industrial Control Systems) is an open source software widely accepted in scientific community as supervisory distributed control system including CODAC (Control, Data Access and Communication) for ITER. However interface with LabVIEW RT systems is not fully mature yet.Evolving interface requirements of platforms like EPICS with IC-HVPS control has been assessed and implemented for monitoring purpose. A test case was implemented to identify compatibility, feasibility, consistency and performance of EPICS server with Input Output Controller (IOCs) implemented in Real-time controller. This paper discusses integration of EPICS IOCs and LabVIEW based Real-time Controller along with an analysis on limitations imposed by such integration.

Measurements and controls implementation for WEST

The WEST platform consists in a major upgrade of Tore Supra towards a steady-state tungsten (W) diverted tokamak. In support of this, significant developments are performed on the measurement systems (diagnostics); the control, data access and communication (CODAC); the plasma control system (PCS), the monitoring and protection of the first wall and modelling to prepare the restart of the plasma. Thanks to collaboration agreements already in force, most of the developments and some hardware procurements are performed with the help of several international partners. This paper discusses the present status of developments regarding the measurements and control for the WEST project. In particular, the integration of about 50 diagnostics in ports is completed, and their in-vessel and ex-vessel installation is underway. The refurbishment of the CODAC network architecture has been completed. The development of the new acquisition units based on PXI and of the Plasma Control System (PCS) is ongoing and some units are already available. In parallel, to prepare the plasma restart, the development of plasma magnetic and kinetic controllers has been performed on simplified plant and actuator models and plasma models.

The new control system of J-TEXT divertor power supply system using J-TEXT real-time framework

The J-TEXT divertor power supply system is designed as a parallel connection, 12-pulse rectifier which is powered by a 100MVA pulse generator unit. To achieve robust current feedback control, high performance real-time control system is required.The new control system adopts a more powerful software framework named J-TEXT real-time framework (JRTF). JRTF is a flexible real-time software framework designed for the implementation of real-time control systems. A JRTF application contains various Application Blocks (AB) which execute specific functions such as feedback computing and protection. JRTF is compatible with ITER standard PFC (Plant Fast Controller) hardware and ITER CODAC (Control, Data Access and Communication) Core software, so it can be monitored and configured by any EPICS based control system. The hardware of the new control system is upgraded to standard ITER fast controller which are much faster and more reliable than former controllers.This control system is the first application of JRTF, and the result shows that the new control system is running properly and stably. It provides an instance for real-time control schemes in J-TEXT, and it may also be applicable to other fusion devices.

Precision Time Protocol support hardware for ATCA control and data acquisition system

An in-house, Advanced Telecom Computing Architecture (ATCA) based control and data acquisition (C&DAQ) subsystem has been developed at Instituto de Plasmas e Fusão Nuclear (IPFN), aiming for compliance with the ITER Fast Plant System Controller (FPSC). Timing and synchronization for the ATCA modules connects to ITER Control, Data Access and Communication (CODAC) through the Timing Communication Network (TCN), which uses IEEE 1588-2008 Precision Time Protocol (PTP) to synchronize devices to a Grand Master Clock (GMC). The TCN infrastructure was tested for an RMS jitter under the limit of 50ns. Therefore, IPFN's hardware, namely the ATCA-PTSW-AMC4 hub-module, which is in charge of timing and synchronization distribution for all subsystem endpoints, shall also perform within this jitter limit. This paper describes a relevant upgrade, applied to the ATCA-PTSW-AMC4 hardware, to comply with these requirements – in particular, the integration of an add-on module “RMC-TMG-1588” on its Rear Transition Module (RTM). This add-on is based on a commercial FPGA-based module from Trenz Electronic, using the ZHAW “PTP VHDL code for timestamping unit and clock”, which features clock offset and drift correction and hardware-assisted time stamping. The main advantage is that timestamps are generated closer to the Physical Layer, at the Gigabit Ethernet Media Independent Interface (GMII), avoiding the timing uncertainties accumulated through the upper layers. PTP code and user software run in a MicroBlaze™ soft-core CPU with Linux in the same FPGA, adding programmability and quick implementation of the desired features and upgrades. The paper briefly presents an overview of the ATCA C&DAQ, presenting the PTP and time stamping solution and how it was hardware-implemented, resulting in the RMC-TMG-1588 module. Finally it will describe the synchronization performance tests and results obtained at ITER site as well as indicating further developments to the system, in order to fulfil ITER's requirements.

A self-description data framework for Tokamak control system design

A Tokamak device consists of numerous control systems, which need to be integrated. CODAC (Control, Data Access and Communication) system requires the configuration settings of these control systems to carry out the integration smoothly. SDD (Self-description data) is designed to describe the static configuration of control systems. ITER CODAC group has released an SDD software package for control system designers to manage the static configuration, but it is specific for ITER plant control systems. Following the idea of ITER SDD, we developed a flexible and scalable SDD framework to develop SDD software for J-TEXT and other sophisticated devices.The SDD framework describes the configuration settings of various control systems, including physical and logical elements and their relation information, in SDD models which are classified into Components and Connections. The framework is composed of three layers: the MongoDB database, an open-source, dynamic schema, NoSQL (Not Only SQL) database; the SDD service, which maps SDD models to MongoDB and handles the transaction and business logic; the SDD applications, which can be used to create and maintain SDD information, and generate various kinds of output using the stored SDD information.

The Design of Global Interlock System in J-TEXT

J-TEXT control, data access, and communication (CODAC) is an advanced control system designed for J-TEXT Laboratory. In J-TEXT CODAC, some critical functions are implemented by some specialized plant systems. Global interlock system (GIS) is a specialized plant system, which provides protection of investment for the J-TEXT. The GIS is in charge of implementing the central protection functions via the plant interlock systems (PISs). This paper provides the design and implementation of the GIS. NI CompactRIO (CRIO) is chosen as the development platform for the GIS. The field-programmable gate array (FPGA) module integrated in CRIO is used to handle input and output signals, and the real-time controller in CRIO is responsible for accessing the EPICS network and configuring the onboard FPGA. Although, currently, the GIS is a small-scale prototype, the core interlock functions are achieved and the performance of GIS meets the requirement of J-TEXT. Now, the GIS has been deployed in J-TEXT and serves in daily experiment.

The J-TEXT CODAC system design and implementation

Inspired by the ITER COntrol, Data Access and Communication (CODAC) and ITER instrumentation and control system, J-TEXT tokamak has upgraded its control system with J-TEXT CODAC system. The J-TEXT CODAC system is based on Experimental Physics and Industrial Control System (EPICS). The J-TEXT CODAC system covers everything in the J-TEXT control system including both central and plant control systems, similar to the ITER I&C system. J-TEXT CODAC system is built around a single central control system called Central CODAC system. All the control functions including conventional control, interlock, safety and other common services are supervised by CCS. The J-TEXT CODAC system has been implemented and tested on J-TEXT. It not only tests some of the ideas in ITER CODAC in real life, but also explores the feasibility of new approaches that is unique in J-TEXT CODAC system.