User control interface for W7-X plasma operation

The configuration of the W7-X control system follows two major design principles. It reflects the strict hierarchy of the machine set-up with a set of subordinated components, which in turn can be run autonomously during commissioning and testing. Secondly, it links the basic machine operation (mainly given by the infrastructure status and the components readiness) and the physics program execution (i.e., plasma operation) on each hierarchy level. The complexity of the control system implies great demands on appropriate user interfaces: specialized tools for specific control tasks allowing a dedicated view on the subject to be controlled, hiding complexity wherever possible and reasonable, providing similar operation methods on each hierarchy level and both manual interaction possibilities and a high degree of intelligent automation. Subject of this article is the description of the operation interface for experiment control: 'Xcontrol' will be designed both for running plasma discharge experiments at W7-X and for components' or diagnostics' operation during autonomous mode or even laboratory experiments. The necessary background information about the control system is given. The main 'Xcontrol' features, such as program composition and validation, manual and automatic control instruments, and process monitoring, will be presented. The implementation principles and the underlying configuration will be discussed. (C) 2007 Elsevier B.V. All rights reserved.