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Abstract: The use of programmable logic controllers (PLC) for automation of electromechanical processes is an industrial control system technology. It is more and more in use within the fusion community. Traditionally PLC based systems are operated and maintained using proprietary SCADA systems (supervisory control and data acquisition). They are hardly ever integrated with the fusion control and data acquisition systems. An overview of the state of the art in fusion is given in the article. At JET an inhouse “black box protocol” approach has been developed to communicate with any external system via a dedicated http based protocol. However, a PLC usually cannot be modified to implement this special protocol. Hence, a software layer has been developed that interfaces a PLC by implementing the PLC specific communication part on one side and the black box protocol part on the other side. The software is completely data driven i.e. editing the data structure changes the logic accordingly. It can be tested using the web capability of the black box protocol. Multiple PLC types from different vendors are supported, thus multiple protocols to interface the PLC are in use. Depending on the PLC type and available tools it can be necessary to program the PLC accordingly. Wendelstein 7-X uses another approach. For every single PLC a dedicated communication from and to CoDaC is implemented. This communication is projected (programmed) in the PLC and configurable (data driven) on the CoDaC side. The protocol is UDP based and observed via timeout mechanisms. The use of PLCs for Wendelstein 7-X is standardized. Therefore a single implementation on the CoDaC side allows communication with any PLC. Measured data from the PLC is archived in the mass data store. Set points from CoDaC can be visualized from within the PLC visualization environment. A detailed description, discussion and comparison of the JET and W7-X approaches is given. [Copyright &y& Elsevier]

Abstract: Federated authentication and authorization systems provide several advantages to collaborative environments, for example, easy authentication integration, simpler user management, easier security policy implementation and quicker implementation of access control elements for new type of resources. A federation integrates different aspects that have to be coordinated by all the organizations involved. The most relevant are: definition of common schemas and attributes, definition of common policies and procedures, management of keys and certificates, management of common repositories and implementation of a home location service. A federation enabling collaboration of European sites has been put into operation. Four laboratories have been integrated and two more organizations (EFDA and KFKI/HAS) are finishing their integration. The federation infrastructure is based on Point of Access to Providers of Information (PAPI), a distributed authentication and authorization system. PAPI technology gives some important features, such as, single sign on for accessing to different resources, mobility for users, and compatibility with open and standard technologies: Java, JNLP protocol, XML-RPC and web technologies among others. In this article, the test-bed of EFDA federation is presented. Some examples of resources, securely shared inside the federation, are shown. Specific issues and experience gained in deploying federated collaboration systems will be addressed as well. [Copyright &y& Elsevier]

Abstract: A new test-bench for the JET real-time project was developed, being capable of generating analogue and digital stimulus signals to the control systems under test using previously stored JET pulse data. This platform allows systems to be more thoroughly tested in a wide range of scenarios before going on-line on the JET machine, reducing development and maintenance times and improving systems performance and reliability. This paper describes the real-time stimulus generator. Three layers of software which were developed to completely control 32 analogue output channels and 32 ATM virtual circuits as a real-time signal generator system: [•] Signal processing on Digital Signal Processor (DSP) software directly accesses the programmable control logic, issuing all the necessary commands using a 64-bit control register and 8-channel rate change registers. Real-time data flow from local SDRAM to digital to analogue converter (DAC) channel circular buffers is also controlled by the DSP. Interrupt service routines (ISRs) were developed to Control Software variables, as well as DMA data transfers. [•] Signal generation and operation as a Linux application controls the DSP in a client–server architecture. The most important functions of this software are: (i) access the JET database via MDSplus, (ii) data transfer to the local DSP SDRAM, (iii) issuing commands to the DSP state machine hardware controller, (iv) check DSP and hardware logic blocks status for errors and (v) the ATM link control. [•] Remote control operation using HTTP server running CGI scripts receives the remote configuration and commands from JET operations management software interface and passes it to the high level Linux software. [Copyright &y& Elsevier]

The TEC community operates the textor device and in doing so collects and stores data from a number of different front-end acquisition systems, processing codes and analysis systems. Due to the evolution of these systems in the past, different, distributed data storage technologies were used to record this data. In an attempt to reduce the number of interfaces client codes have to use when accessing data from these data stores, an “umbrella” concept was developed: a software-layer that covers (as an “umbrella”) as many as possible of these stores and provides a unified access mechanism to them. We explored the possibility of using the widely supported HTTP protocol for this purpose; this is the core protocol of the World-Wide-Web and it is capable of transporting almost any type of data. The concepts behind using this protocol were based on earlier work at JET. Access via this umbrella has been provided to the most important data stores around textor and access to others is being added regularly. Clients codes, libraries and programs have been developed for several user environments. The HTTP based concepts and the data-access via this system have been found to be highly portable. This paper gives an overview of the TEC Web-Umbrella system, it describes the basic concepts of this system and it presents some of the client-side codes and programs. The paper also reports on some first (tentative) user experiences with it. [Copyright &y& Elsevier]