Author: Valcárcel, D.F.
Paper Title Page
WEPMN036 Comparative Analysis of EPICS IOC and MARTe for the Development of a Hard Real-Time Control Application 961
  • A. Barbalace, A. Luchetta, G. Manduchi, C. Taliercio
    Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova, Italy
  • B. Carvalho, D.F. Valcárcel
    IPFN, Lisbon, Portugal
  EPICS is used worldwide to build distributed control systems for scientific experiments. The EPICS software suite is based around the Channel Access (CA) network protocol that allows the communication of different EPICS clients and servers in a distributed architecture. Servers are called Input/Output Controllers (IOCs) and perform real-world I/O or local control tasks. EPICS IOCs were originally designed for VxWorks to meet the demanding real-time requirements of control algorithms and have lately been ported to different operating systems. The MARTe framework has recently been adopted to develop an increasing number of hard real-time systems in different fusion experiments. MARTe is a software library that allows the rapid and modular development of stand-alone hard real-time control applications on different operating systems. MARTe has been created to be portable and during the last years it has evolved to follow the multicore evolution. In this paper we review several implementation differences between EPICS IOC and MARTe. We dissect their internal data structures and synchronization mechanisms to understand what happens behind the scenes. Differences in the component based approach and in the concurrent model of computation in EPICS IOC and MARTe are explained. Such differences lead to distinct time models in the computational blocks and distinct real-time capabilities of the two frameworks that a developer must be aware of.  
poster icon Poster WEPMN036 [2.406 MB]  
WEPMN014 The Software and Hardware Architectural Design of the Vessel Thermal Map Real-Time System in JET 905
  • D. Alves, A. Neto, D.F. Valcárcel
    IPFN, Lisbon, Portugal
  • G. Arnoux, P. Card, S. Devaux, R.C. Felton, A. Goodyear, D. Kinna, P.J. Lomas, P. McCullen, A.V. Stephen, K-D. Zastrow
    CCFE, Abingdon, Oxon, United Kingdom
  • S. Jachmich
    RMA, Brussels, Belgium
  The installation of ITER-relevant materials for the plasma facing components (PFCs) in the Joint European Torus (JET) is expected to have a strong impact on the operation and protection of the experiment. In particular, the use of all-beryllium tiles, which deteriorate at a substantially lower temperature than the formerly installed CFC tiles, imposes strict thermal restrictions on the PFCs during operation. Prompt and precise responses are therefore required whenever anomalous temperatures are detected. The new Vessel Thermal Map (VTM) real-time application collects the temperature measurements provided by dedicated pyrometers and Infra-Red (IR) cameras, groups them according to spatial location and probable offending heat source and raises alarms that will trigger appropriate protective responses. In the context of JET's global scheme for the protection of the new wall, the system is required to run on a 10 millisecond cycle communicating with other systems through the Real-Time Data Network (RTDN). In order to meet these requirements a Commercial Off-The-Shelf (COTS) solution has been adopted based on standard x86 multi-core technology, Linux and the Multi-threaded Application Real-Time executor (MARTe) software framework. This paper presents an overview of the system with particular technical focus on the configuration of its real-time capability and the benefits of the modular development approach and advanced tools provided by the MARTe framework.
See the Appendix of F. Romanelli et al., Proceedings of the 23rd IAEA Fusion Energy Conference 2010, Daejeon, Korea
poster icon Poster WEPMN014 [5.306 MB]  
THDAULT06 MARTe Framework: a Middleware for Real-time Applications Development 1277
  • A. Neto, D. Alves, B. Carvalho, P.J. Carvalho, H. Fernandes, D.F. Valcárcel
    IPFN, Lisbon, Portugal
  • A. Barbalace, G. Manduchi
    Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova, Italy
  • L. Boncagni
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • G. De Tommasi
    CREATE, Napoli, Italy
  • P. McCullen, A.V. Stephen
    CCFE, Culham, Abingdon, Oxon, United Kingdom
  • F. Sartori
    F4E, Barcelona, Spain
  • R. Vitelli
    Università di Roma II Tor Vergata, Roma, Italy
  • L. Zabeo
    ITER Organization, St. Paul lez Durance, France
  Funding: This work was supported by the European Communities under the contract of Association between EURATOM/IST and was carried out within the framework of the European Fusion Development Agreement
The Multi-threaded Application Real-Time executor (MARTe) is a C++ framework that provides a development environment for the design and deployment of real-time applications, e.g. control systems. The kernel of MARTe comprises a set of data-driven independent blocks, connected using a shared bus. This modular design enforces a clear boundary between algorithms, hardware interaction and system configuration. The architecture, being multi-platform, facilitates the test and commissioning of new systems, enabling the execution of plant models in offline environments and with the hardware-in-the-loop, whilst also providing a set of non-intrusive introspection and logging facilities. Furthermore, applications can be developed in non real-time environments and deployed in a real-time operating system, using exactly the same code and configuration data. The framework is already being used in several fusion experiments, with control cycles ranging from 50 microseconds to 10 milliseconds exhibiting jitters of less than 2%, using VxWorks, RTAI or Linux. Codes can also be developed and executed in Microsoft Windows, Solaris and Mac OS X. This paper discusses the main design concepts of MARTe, in particular the architectural choices which enabled the combination of real-time accuracy, performance and robustness with complex and modular data driven applications.
slides icon Slides THDAULT06 [1.535 MB]  
FRAAULT04 Centralised Coordinated Control to Protect the JET ITER-like Wall. 1293
  • A.V. Stephen, G. Arnoux, T. Budd, P. Card, R.C. Felton, A. Goodyear, J. Harling, D. Kinna, P.J. Lomas, P. McCullen, P.D. Thomas, I.D. Young, K-D. Zastrow
    CCFE, Abingdon, Oxon, United Kingdom
  • D. Alves, D.F. Valcárcel
    IST, Lisboa, Portugal
  • S. Devaux
    MPI/IPP, Garching, Germany
  • S. Jachmich
    RMA, Brussels, Belgium
  • A. Neto
    IPFN, Lisbon, Portugal
  Funding: This work was carried out within the framework of the European Fusion Development Agreement. This work was also part-funded by the RCUK Energy Programme under grant EP/I501045.
The JET ITER-like wall project replaces the first wall carbon fibre composite tiles with beryllium and tungsten tiles which should have improved fuel retention characteristics but are less thermally robust. An enhanced protection system using new control and diagnostic systems has been designed which can modify the pre-planned experimental control to protect the new wall. Key design challenges were to extend the Level-1 supervisory control system to allow configurable responses to thermal problems to be defined without introducing excessive complexity, and to integrate the new functionality with existing control and protection systems efficiently and reliably. Alarms are generated by the vessel thermal map (VTM) system if infra-red camera measurements of tile temperatures are too high and by the plasma wall load system (WALLS) if component power limits are exceeded. The design introduces two new concepts: local protection, which inhibits individual heating components but allows the discharge to proceed, and stop responses, which allow highly configurable early termination of the pulse in the safest way for the plasma conditions and type of alarm. These are implemented via the new real-time protection system (RTPS), a centralised controller which responds to the VTM and WALLS alarms by providing override commands to the plasma shape, current, density and heating controllers. This paper describes the design and implementation of the RTPS system which is built with the Multithreaded Application Real-Time executor (MARTe) and will present results from initial operations.
slides icon Slides FRAAULT04 [2.276 MB]