Joshua Stillerman

MDS/MIT high‐speed data‐acquisition and analysis software system

MDS is a high‐speed VAX‐based CAMAC‐oriented data‐acquisition and analysis system. It was developed at MIT for use on the ALCATOR C and TARA experiments. MDS consists of a coherent set of general purpose, flexible tools for experimental data handling. Using MDS a scientist can set up a complete diagnostic including CAMAC data acquisition, display, and analysis without writing any code. MDS has been in use at MIT for over two years and is also installed and operational at numerous other labs including PPPL, Oak Ridge National Laboratory, UCLA, and Sandia National Laboratory. The computer equipment on which MDS is installed ranges from large VAXclusters to small stand‐alone MicroVAX II systems. The authors of this paper hope to present an overview for those unfamiliar with the MDS system, to discuss planned improvements in the system, and to discuss ideas for future enhancements that may benefit all the MDS sites.

CompactPCI based Data acquisition with MDSplus

Alcator C-Mod is incorporating CompactPCI based data acquisition cards into the MDSplus data acquisition system. Each crate includes a diskless computer running the mdsip server from MDSplus under the Linux operating system, and one or more digitizer cards with onboard memory. A minimal set of software is downloaded to this computer at boot time allowing it to arm and read out the cards when requested by the host data acquisition computers. This diskless design is very attractive in our high field environment and simplifies the maintenance and configuration of the embedded computers. Separating the digitizers from the data acquisition computers allows the data acquisition to be done in a platform independent way. Ethernet provides robust, inexpensive communications. The initial digitizer cards have thirty-two 16 bit, 250 KHz digitizers, 128 Msamples of memory, two arbitrary waveform generators and eight programmable digital outputs. CompactPCI provides an attractive alternative to our aging CAMAC based data acquisition equipment.

Alcasim simulation code for Alcator C-Mod

A Matlab-Simulink simulation code Alcasim has been developed for Alcator C-Mod. The simulator includes models of the tokamak and plasma, the magnetic diagnostics and the power supplies. Alcasim runs the real-time control code of Alcator C-Mod and has been integrated with the standard software available to design the target waveforms and control algorithms. Extensive testing of the simulator has shown good agreement with experimental data. The short simulation time, which is around 3 minutes on a standard PC, makes Alcasim a close to real-time tool available to the physics operator to test the control programming in between C-Mod discharges. The Matlab-Simulink-IDL environment of Alcasim is also suitable to test new algorithms and architectures off-line and to develop advanced model-based control strategies

A Multithreaded Modular Software Toolkit for Control of Complex Experiments

A multithreaded modular software toolkit has been developed for centralized monitoring and control of complex scientific experiments and instruments. The Modular Control Toolkit (MCT) supports Unix-like operating systems and provides a reusable framework for user-developed modules to share data, setup software interlocks, and utilize a dedicated thread for hardware communication.

Transmitter Protection System Upgrade Design for Lower Hybrid Current Drive System on Alcator C-Mod

An upgrade to the transmitter protection system (TPS) is being designed as part of the scheduled expansion of the Alcator C-Mod Lower Hybrid Current Drive (LHCD) transmitter system from 12 to 16 klystrons. The upgrade design is being done as collaborative effort between Alcator C-Mod and Rockfield Research, Inc. as Phases 1 and II of a Small Business Innovative Research (SBIR) grant. A plan is in place to first implement the new design for the cart supporting 4 additional klystrons and then to upgrade the TPS for the existing three carts supporting the 12 existing klystrons. Some parts must be added before longer pulse operation. Experience in operating the existing LHCD system and a study of the klystron design have indicated a need for this upgrade to improve the protection to the klystrons, improve reliability and noise immunity, improve personnel safety and reduce the size of the system.

THE TARA CONTROL, MONITORING, DATA ACQUISITION, AND ANALYSIS SYSTEM

Experiments at the MIT Tara Tandem Mirror utilize an integrated system for control, monitoring, data acquisition, physics analysis, and archiving. This system consists of two distinct parts with narrowly defined information interchange; one to provide automated control and real time monitoring of engineering functions and one to acquire, analyze, and display data for physics in near real time. Typical machine operation achieves a total cycle time of 3 to 8 minutes with 5 to 7 Mbytes of data stored and with ~160 individual signals displayed in hardcopy on ~10 pages.