[en] The technology of the formerly used Control Architecture for BOP area and some support systems is substantially based on hardware interconnections 'point to point' between field instruments, transmitters and switches, logic cabinets in Equipment Room (ER), with electronic cards and cabled static elements, and a conventional operator interface in Main Control Room (MCR), local panels with hand-switches, electromechanical indicators, lamps and chart-recorders. Functional group commands, operable by ER cabinets, and single component commands, operable directly from local panels close to the drivers in field, are also available. The digital signals to/from field or MCR are transmitted to/from the logic cabinets passing through a centralized Control Distribution Frame (CDF). It provides also the signals dispatching between the different I-and-C systems used (included the AECL computers, where trending, data logger, supervision activities and some control function are realized), and signal hardware application when it is necessary. The criteria leading to the choice of a product to implement a new control architecture have been: - the capability to fulfill all the current Unit 1 Control System requirements and some additional ones forced by the present up-dating; - the use of a modern technology, with the possibility to easily extend its features, enhancing the process control capability, the global performances, the operating and maintenance activities; - the choice to limit the impacts, mainly in terms of human machine interface variations and, moreover, the replacement cost. In the section of the paper entitled Distributed Control System (DCS) the main features are described and the issues of hardware reduction, software and control system layout optimizations, as well as an advanced operator interface are presented. The section three is dealing with a proposal for Unit 1 Control Architecture while in the section four the DCS v.s. traditional technology is discussed

[en] Due to low power operation, intrinsic integrability and compatibility with CMOS processing, aluminum nitride (AlN) piezoelectric (PZE) microcantilevers are a very attractive paradigm for resonant gas sensing. In this paper, we theoretically investigate their ultimate limit of detection and enunciate design rules for performance optimization. The reduction of the AlN layer thickness is found to be critical. We further report the successful development and implementation in cantilever structures with a 50 nm thick active PZE AlN layer. Material characterizations demonstrate that the PZE e_3_1 coefficient can remain as high as 0.8 C m"−"2. Electrically transduced frequency responses of the fabricated devices are in good agreement with analytical predictions. Finally, we demonstrate the excellent frequency stability with a 10"−"8 minimum Allan deviation. This exceptionally low noise operation allows us to expect a limit of detection as low as 53 zg µm"−"2 and demonstrate the strong potential of AlN PZE microcantilevers for high resolution gas detection