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The construction of MITICA, the full-size prototype of the ITER Heating Neutral Beam Injectors (HNBs) is in progress at the Neutral Beam Test Facility (NBTF) located in Padova, Italy. The design of the central control (CODAS) and interlock (CIS) systems is progressing taking into account the requirements coming from the MITICA plant units, in terms of number and type of interface signals, data sampling frequency values, operating states, protection actions and required reaction times and reliability. As the HNBs will be ITER components, additional requirements derive from the ITER plant control design handbook that specifies the design criteria and standard technologies to be applied to ITER plant systems. A distinction must be made in MITICA between plant units that will be part of the HNB, such as the power supply systems, and plant units that are auxiliaries, such as the gas and vacuum system. In the NBTF these components shall interface with MITICA CODAS and CIS, whereas in ITER they will be autonomous plant systems providing services to the HNB. The distinction reported above suggests defining the architecture of MITICA Instrumentation and Control (I&C) as split into the following functional blocks: i) HNB plant system including components that will be part of the HNB; ii) Service plant system including all operational plant units that need control in the NBTF but are implemented outside the ITER HNB; iii) Diagnostics plant system; iv) Central I&C (CODAS and CIS). The paper presents the requirements for MITICA CODAS and CIS and derives from these the system architecture. The design of CODAS and CIS is discussed with reference to the lesson learned in the implementation of SPIDER CODAS and CIS (the NBTF ion source test bed) and to the technologies suitable for the implementation.

The ITER Neutral Beam Test Facility (NBTF) is currently under construction at Consorzio RFX, Padova, Italy. The NBTF includes two experimental devices: SPIDER for the study of the ion source and MITICA for the development of the full-size HNB prototype. Even if the two experiments share many architectural aspects in their Control and Data Acquisition System (CODAS), there are nevertheless some significant differences because MITICA must adhere to ITER's directives for plant control design. This paper describes the architecture of the MITICA timing system that represents one of the first examples of integration of IEEE1588 timing functions in fusion research medium-scale experiments. Timing functions are required in MITICA CODAS to: 1) Synchronize data acquisition and assign a timestamp to each data sample; 2) Supervise the generation of events, trigger a reaction of the control system and/or provide enhanced data acquisition in a time window centered on the event occurrence time. The IEEE1588 time synchronization protocol ensures sub-microsecond clock alignment among devices connected via a LAN. Therefore, it has the potential advantage of avoiding direct cabling among the involved actors, being all the synchronization messages exchanged over the LAN. A feature that IEEE1588 does not cover is the management of asynchronous events that may trigger some actions. Asynchronous events may trigger: 1) Enhanced data acquisition (e.g. with a higher sampling speed) during a time window centered on the trigger occurrence time; 2) Real-time response from the control system. While the management of events triggering control actions is under the responsibility of the real- time control system, for events triggering enhanced data acquisition, the "lazy triggers" solution is adopted in MITICA. This solution allows events to be communicated via LAN, compensating the delay in network communication will be compensated by means of circular buffers at the ADC side.

RFXMod2 is an upgrade of RFXMod that will use a modified shell and mechanical structure in order to enhance plasma proximity to the shell and therefore to improve plasma control. The Control and Data Acquisition System for most of the plant systems and diagnostics previously used in RFXMod will be refurbished, while others will be completely re-built. The most important component that will be completely renewed is the Electromagnetic Probes (EM) data acquisition system. In the former system data acquisition and real-time control were implemented using two different technologies, i.e. CompactPCI and VME, respectively. In RFXMod2 a new architecture based on XILINX Zynq FPGA will be used to carry out at the same time both high-speed data acquisition and resampled data streaming for active plasma control. Moreover, numeric integration of EM signals will be carried out by the same FPGA supervising data acquisition and streaming. The use of MDSplus will be retained in RFXMod2, while the MARTe framework used for real-time plasma control will be replaced by MARTe2, a new framework developed under strict software quality standards. Plant control in RFXMod2 will be supervised by WinCC-OA, replacing the previous FactoryLink SCADA systems. Older plant units such as vacuum control using outdated S5 PLCs will be replaced by new systems, using OPC communication with the supervisory system. Old CAMAC equipment in diagnostics will be replaced by CompactPCI technology, making it uniform with the rest of the diagnostic data acquisition systems. Finally, specialized devices implemented in CAMAC such as timing sequence generators will be replaced by custom devices implemented using the same Zynq FPGA technology of the EM data acquisition devices.

The SPIDER central interlock is a centralized electronic system to coordinate the protection functions within the SPIDER experiment (Source for the Production of Ions of Deuterium Extracted from an RF plasma), i.e. the full-size ion source prototype of the ITER Neutral Beam Injector. Due to the system time requirements, the SPIDER central interlock has been implemented by using PLCs for the slow functions (100 ms reaction time from fault detection to protection command emission) and National Instruments CompactRIO for the fast functions (10 μs from fault detection to command emission). The paper describes in detail the system hardware and software implementation. The results of the first tests and commissioning are reported with particular focus on the implementation, execution, and performance of the interlock fast functions.

High-speed event driven acquisition is normally performed by analog-to-digital converter (ADC) boards with a given number of pretrigger sample and posttrigger sample that are recorded upon the occurrence of a hardware trigger. A direct physical connection is, therefore, required between the source of event (trigger) and the ADC, because any other software-based communication method would introduce a delay in triggering that would turn out to be not acceptable in many cases. This paper proposes a solution for the relaxation of the event communication time that can be, in this case, carried out by software messaging (e.g., via an LAN), provided that the system components are synchronized in time using the IEEE 1588 synchronization mechanism. The information about the exact event occurrence time is contained in the software packet that is sent to communicate the event and is used by the ADC FPGA to identify the exact sample in the ADC sample queue. The length of the ADC sample queue will depend on the maximum delay in software event message communication time. A prototype implementation using a National FlexRIO FPGA board connected with an ADC device is presented as the proof of concept.

Streamed data visualization is a new requirement for long lasting discharges and more in general for every long lasting related experiment, such as the ITER Neutral Beam test facility. A prerequisite for live visualization is the ability of the underlying data system to support streaming in data acquisition. Data streaming is supported in MDSplus, a widely adopted data system in fusion research, by means of segments. A signal in MDSplus is stored as a sequence of segments that can be saved individually as soon as the associated data chunk is available. In this way, at any time during the experiment sequence, segments stored so far are readily available and can be used for on-line analysis and visualization. On-line visualization is routinely performed during long lasting experiments, but implementing streamed data visualization, such as strip charts, would overload the data system, especially if a large number of charts are being displayed. A different approach for streamed data visualization is proposed here, using MDSplus events, rather than directly accessing stored data. MDSplus events are used to synchronize components during the experiment sequence, using a multicast organization. A listener can register for a given event name and it will be notified when an event with that name is generated. Events can bring data and are implemented as UDP multicast packets. A data acquisition program can therefore, in addition to using MDSplus for streaming data segments, generate MDSplus events bringing the most recent chunk of samples. In order to make data carried by events available to Web applications, a Node.js server has been developed, listening for the UDP packets and updating the connected Web clients using HTML5 Server Sent Events. In turn, Web client will update the displayed waveforms using chart js. Compared with other approaches for streamed data visualization, the presented one offers several advantages. Firstly, MDSplus events represent a much lighter solution in respect to repeatedly accessing stored data in pulse files. Then, Node.js proved a very effective environment for originating the Web pages and to implement the bridge between MDSplus events and HTML5 Server Sent events, resulting in an amazingly low number of lines of JavaScript code. Finally, chart js proved an effective tool for waveform display in Web pages, with a stunning performance in animation.

The RFX-mod2 Nuclear Fusion experiment is an upgrade of RFX-mod. Among the other improvements in machine structure and diagnostics, a larger number of electromagnetic probes (EMs) is foreseen to provide more information about plasma instabilities and to allow an improved real-time plasma control. An Analog to Digital Converter (ADC) architecture able to provide both transient recording and real-time streaming is foreseen in RFX_mod2. Transient recording provides full speed data acquisition (up to 1 MSample/s) by recording data in local memory and reading memory content after the plasma discharge. Real-time streaming of subsampled data is required for active control. The chosen technology is based on the XILINX Zynq architecture that provides in the same chip a multicore ARM processor tightly couple to a FPGA. Time critical functions carried out by the FPGA in this context are: 1) The management of a circular data buffer and the DMA transfer in RAM of pre and post trigger samples after the trigger has been received; 2) Antialiasing filtering and subsampling of the samples to be streamed. The resulting samples are enqueued in a FIFO accessed by the processor. The functions carried out by the processor are: 1) The management of the configuration setting, received via TCP/IP or HTTP. The processor validates the configuration and write the appreciate registers in the FPGA; 2) Offline data readout of acquired samples in transient recording; 3) Network data streaming of subsampled data read from the FIFO and sent in UDP packets to the active plasma control system.

The present and future data management requirements for fusion experiments are presented along with the currently adopted solutions. Even if the presented solution fulfil the requirements of the current experiments, the next generation fusion devices are likely to produce/require an unpreceded amount of data. For this reason, the solutions adopted nowadays, and also foreseen for the experiments under construction, might prove not enough scalable. Information Technology already provides efficient solutions for big data management, successfully employed for large cloud applications and social media. In particular, MongoDB, Cassandra and Hadoop represent promising candidates for the next generation experiments because their combined usage covers the specific data requirements for fusion research.

A modern Control and Data Acquisition System (CODAS) must provide an integrated management of supervision, data acquisition and real-time control and a data centric view of the system combining raw, elaborated and configuration data. These requirements have been addressed by the CODAS system of the SPIDER experiment in the ITER Neutral Beam Test Facility. The solution adopted in SPIDER CODAS integrates, by means of few interface components, three frameworks used in nuclear fusion and accelerator communities. A further refinement has recently started, aiming at providing a solution that is complete and generic, and, as such, easily portable to new applications, ranging from small systems to future fusion experiments. The refined system described in the paper will be deployed in the ECT-FALCON Test Facility, used to test the ITER EC launcher components and the European Gyrotron prototype. Its implementation in other test facilities is foreseen, in order to provide a fast track to the development of complete and integrated control and data acquisition.

System on Chip is a hardware solution combining different hardware devices in the same chip. In particular, the XILINX Zynq solution, implementing an ARM processor and a configurable FPGA on the same chip, is a candidate technology for a variety of applications of interest in fusion research, where FPGA fast logic must be combined with CPU processing for high-level functions and communication. Developing Zynq based applications requires the development of the FPGA logic using the XILINX Vivado IDE, mapping information between the FPGA device and the processor address space, developing the kernel drivers for interaction with the FPGA device and developing the high level application programs in user space for the supervision and the integration of the system. The paper presents a framework that integrates all the above steps and greatly simplifies the overall process. The framework has been used for the development of a programmable timing device in Wendelstein 7-X. The development of new devices integrating data acquisition and timing functions is also foreseen for RFX-mod.

The NIO1 (Negative Ion Optimization, phase 1) experiment is a versatile test bench with goal of delivering a negative hydrogen beam current of 135mA accelerated to -60kV and divided into 9 beamlets. NIO1 is operated by Consorzio RFX and INFN in the framework of the activities aimed at the enhancement of negative ion sources for production of large ion beams for plasma heating in nuclear fusion devices and accelerator applications. For the NIO1 device an Acquisition, Data Retrieval, Interlock and Control (ADRIC) system was realised. The present paper gives a detailed description of the overall structure of ADRIC, which integrates together the various components; the single parts are also described, particularly highlighting the adoption of novel equipment. A special asset of this system is its flexibility when adding new components.The NIO1 (Negative Ion Optimization, phase 1) experiment is a versatile test bench with goal of delivering a negative hydrogen beam current of 135mA accelerated to -60kV and divided into 9 beamlets. NIO1 is operated by Consorzio RFX and INFN in the framework of the activities aimed at the enhancement of negative ion sources for production of large ion beams for plasma heating in nuclear fusion devices and accelerator applications. For the NIO1 device an Acquisition, Data Retrieval, Interlock and Control (ADRIC) system was realised. The present paper gives a detailed description of the overall structure of ADRIC, which integrates together the various components; the single parts are also described, particularly highlighting the adoption of novel equipment. A special asset of this system is its flexibility when adding new components.

The realization of the ITER Neutral Beam Test Facility (NBTF) and the start the experimental phase are important tasks of the fusion roadmap, since the target requirements of injecting to the plasma a beam of Deuterium atoms with a power up to 16.5 MW, at 1MeV of energy and with a pulse length up to 3600s have never been reached together before. The ITER NBTF, called PRIMA (Padova Research on ITER Megavolt Accelerator), is hosted in Padova, Italy; it includes two experiments: MITICA, the full-scale prototype of the ITER injector and SPIDER, the full-size negative ion source. The realization promoted by the ITER organization is carried out with the contribution of the European Union, channeled through the Joint Undertaking for ITER (F4E), of the Consorzio RFX which hosts the Test Facility, the Japanese and the Indian ITER Domestic Agencies (JADA and INDA) and several European laboratories, such as IPP-Garching, KIT-Karlsruhe, CCFECulham, CEA-Cadarache. The early start of operation of PRIMA experiments is urgent because sufficient experimental time is necessary to face and solve the issues related to the achievement of the desired performance in time for the ITER operation, requiring NBI since the beginning. Substantial progresses have been recently achieved: the buildings construction, begun in October 2012, has been completed by the end of 2015 and the installation of some components has been started since the end of 2014. The SPIDER realization is well advanced: the installation phase is proceeding in good agreement with the general plan; it is expected to be almost completed by the end of 2016. In parallel, the commissioning of the SPIDER power supply (PS) and auxiliary plant systems is being proceeding. Tests at full power and remote control are planned, including also those addressed to reproduce the grid breakdowns and to test the relevant protections. The design of the MITICA injector components was completed in 2015their procurement is being made through a number of tenders, some of them already launched. The HV Power Supply system of the MITICA 1MV accelerator, provided by JADA, was delivered on site in December 2015. The challenging installation of these components, including the step-up transformers and the SF6 gas insulated transmission line, started soon after and will go on throughout 2016. The present phase, with the PRIMA buildings continuously filled with new components, with the installation activities progressing and with also the commissioning and testing phase starting represents a substantial step forward toward the main target. The paper will describe the main challenges the Project Team has dealt during this phase and the important feedback derived for the ITER HNB systems both from the technical and the organizational standpoints.

Fast control and data acquisition are required in the ion source test bed of the ITER neutral beam test facility, referred to as SPIDER. Fast control will drive the operation of the power supply systems with particular reference to special asynchronous events, such as the breakdowns. These are short-circuits among grids or between grids and vessel that can occur repeatedly during beam operation. They are normal events and, as such, they will be managed by the fast control system. Cycle time associated to such fast control is down to hundreds of microseconds. Fast data acquisition is required when breakdowns occur. Event-driven data acquisition is triggered in real time by fast control at the occurrence of each breakdown. Pre- and post-event samples are acquired, allowing capturing information on transient phenomena in a whole time-window centered on the event. Sampling rate of event-driven data acquisition is up to 5 MS/s. Fast data acquisition may also be independent of breakdowns as in the case of the cavity ring-down spectroscopy where data chunks are acquired at 100 MS/s in bursts of 1.5 ms every 100 ms and are processed in real time to produce derived measurements. The paper after the description of the SPIDER fast control and data acquisition application will report the system design based on commercially available hardware and the MARTe and MDSplus software frameworks. The results obtained by running a full prototype of the fast control and data acquisition system are also reported and discussed. They demonstrate that all SPIDER fast control and data acquisition requirements can be met in the prototype solution.

The ITER Neutral Beam (NBI) Test Facility, under construction in Padova, Italy consists in the ITER full scale ion source for the heating neutral beam injector, referred to as SPIDER, and the full size prototype injector, referred to as MITICA. The Control and Data Acquisition System (CODAS) for SPIDER has been developed and is going to be in operation in 2016. The system is composed of four main components: Supervision, Slow Control, Fast Control and Data Acquisition. These components interact with each other to carry out the system operation and, since they represent a common pattern in fusion experiments, software frameworks have been used for each (set of) component. In order to reuse as far as possible the architecture developed for SPIDER, it is important to clearly define the boundaries and the interfaces among the system components so that the implementation of any component can be replaced without affecting the overall architecture. This work reports the experience gained in the development of SPIDER components, highlighting the importance in the definition of generic interfaces among component, showing how the specific solutions have been adapted to such interfaces and suggesting possible approaches for the development of other ITER subsystems.

The Neutral Beam Test Facility, which is under construction in Padova, Italy, is developing the ITER full-scale ion source for the ITER heating neutral beam injectors (HNB), referred to as the SPIDER experiment, and the full-size prototype injector, referred to as MITICA. The SPIDER control and data acquisition system (CODAS) has been developed and its construction will start in 2014. Slow control and data acquisition will be based on the ITER CODAC Core System software suite that has been designed to facilitate the integration of ITER plant systems with CODAC. Fast control and data acquisition will use solutions specific to the test facility, as the corresponding concepts are not fully mature in the ITER design. The ITER hardware catalogue for fast control has been taken into consideration. The software development will be based on the integration of MDSplus and MARTe, two framework software packages that are well known in the fusion community, targeting data organization and fast realtime control, respectively. The paper will revise the system requirements and the system design, and will show the results already achieved in terms of system integration. In addition, the paper will report the experience in the usage of different cooperating software frameworks and in the integration of industrial procured plant systems.

Simulink is a graphical data flow programming tool for modeling and simulating dynamic systems. A component of Simulink, called Simulink Coder, generates C code from Simulink diagrams. MARTe is a framework for the implementation of real-time systems, currently in use in several fusion experiments. MDSplus is a framework widely used in the fusion community for the management of data. The three systems provide a solution to different facets of the same process, that is, real-time plasma control development. Simulink diagrams will describe the algorithms used in control, which will be implemented as MARTe GAMs and which will use parameters read from and produce results written to MDSplus pulse files. The three systems have been integrated in order to provide a tool suitable to speed up the development of real-time control applications. In particular, it will be shown how from a Simulink diagram describing a given algorithm to be used in a control system, it is possible to generate in an automated way the corresponding MARTe and MDSplus components that can be assembled to implement the target system.

Experimental results and theoretical studies call for Reversed Field Experiment (RFX) machine and power supply improvements to allow studies that go beyond those of a conventional Reversed Field Pinch (RFP) with passively stabilized turbulent MHD dynamo. The new paths opened by recent results in RFX and other RFP machines are introduced; then the goals and the design lines of the technical modifications of RFX, mainly addressed to improve the first wall, the plasma magnetic boundaries and to increase the operational flexibility of the toroidal field circuit power supply, are reported.

The paper deals with an automatic computer procedure developed to detect errors or faults in the signal waveforms measured during the operation of the RFX machine. These data are generated by the diagnostic equipment and other sensors installed in the machine and in its power supplies. The signal check is paramount, since even a single faulty waveform may lead to wrong results in the post-processing phase. Due to their large number, the manual inspection of each signal after the pulse is impossible. The check has to be performed as quickly as possible, in order to identify and discard the defective waveforms before their on-line elaboration. To this purpose, the on-line signal check program is integrated in the control data acquisition system of RFX. Presently, the procedure is being used to check the quality of the saved machine pulse data.

The control and data acquisition system of the RFX experiment was designed and implemented during the second half of the 1980s, and several hardware components used in the system are currently obsolete. For these reasons an extensive redesign of the control and data acquisition system has been considered at RFX, with the aim of preserving well-tested concepts but at the same time replacing out-of-date technology. The update of the control and data acquisition system is possible due to the fact that major changes are to be accomplished in the machine power supply systems, requiring a long period of machine shutdown. In addition, important modifications of the machine load assembly are under consideration, which introduce new requirements for the control system. The introduction of modern technologies for distributed data acquisition is discussed and the planned organisation of the new system is presented.

New analog signal conditioning electronics and data acquisition systems have been developed for the soft x-ray and bolometric tomography diagnostic in the reverse field pinch experiment (RFX). For the soft x-ray detectors the analog signal processing includes a fully differential current to voltage conversion, with up to a 200 kHz bandwidth. For the bolometers, a 50 kHz carrier frequency amplifier allows a maximum bandwidth of 10 kHz. In both cases the analog signals are digitized with a 1 MHz sampling rate close to the diagnostic and are transmitted via a transparent asynchronous xmitter/receiver interface (TAXI) link to purpose built Versa Module Europa (VME) modules which perform data acquisition. A software library has been developed for data preprocessing and tomographic reconstruction. It has been written in C language and is self-contained, i.e., no additional mathematical library is required. The package is therefore platform-free: in particular it can perform online analysis in a real-time application, such as continuous display and feedback, and is portable for long duration fusion or other physical experiments. Due to the modular organization of the library, new preprocessing and analysis modules can be easily integrated in the environment. This software is implemented in RFX over three different platforms: open VMS, digital Unix, and VME 68040 CPU. (C) 1997 American Institute of Physics.

The paper presents the user interface aspects of the control and data acquisition system (SIGMA) of the RFX nuclear fusion experiment. SIGMA uses programmable controllers (PLCs) for slow signals and VAX based CAMAC for the fast data acquisition and timing tasks. The paper briefly summarises the technical aspects of the user interface: PLC based systems use operating consoles which employ IBM PC/AT compatibles running a commercial plant supervision package. The VAX based part employs VAXstations as user consoles with an extensive graphical user interface (initially DECwindows, now Motif). The use of these tools is illustrated by presenting the entire operation sequence for an RFX shot.

The paper describes the experience gained in the development and maintenance of the data acquisition system for the RFX nuclear fusion experiment. The design of the system core started in 1987 and the system was ready at the beginning of the machine operation in late 1991. Since the early design stage it was clear that a careful definition of the system architecture was crucial for allowing the system to cope with the expected improvement in the hardware performance. Not all the initial design choices proved successful for this purpose. In the paper the (positive or negative) consequences of the main design choices of the system are reported.

Convolutional neural networks (CNNs) have found applications in many image processing tasks, such as feature extraction, image classification, and object recognition. It has also been shown that the inverse of CNNs, so- called deconvolutional neural networks, can be used for inverse problems such as plasma tomography. In essence, plasma tomography consists in reconstructing the 2D plasma profile on a poloidal cross-section of a fusion device, based on line-integrated measurements from multiple radiation detectors. Since the reconstruction process is computationally intensive, a deconvolutional neural network trained to produce the same results will yield a significant computational speedup, at the expense of a small error which can be assessed using different metrics. In this work, we discuss the design principles behind such networks, including the use of multiple layers, how they can be stacked, and how their dimensions can be tuned according to the number of detectors and the desired tomographic resolution for a given fusion device. We describe the application of such networks at JET and COMPASS, where at JET we use the bolometer system, and at COMPASS we use the soft X-ray diagnostic based on photodiode arrays.