ITER prototype fast plant system controller

ITER CODAC Design identified the need for slow and fast control plant systems, based respectively on industrial automation technology with maximum sampling rates below 100 Hz, and on embedded technology with higher sampling rates and more stringent real-time requirements. The fast system is applicable to diagnostics and plant systems in closed-control loops whose cycle times are below 1 ms. Fast controllers will be dedicated industrial controllers with the ability to supervise other fast and/or slow controllers, interface to actuators and sensors and high performance networks (HPN).This contribution presents the engineering design of two prototypes of a fast plant system controller (FPSC), specialized for data acquisition, constrained by ITER technological choices. This prototyping activity contributes to the Plant Control Design Handbook (PCDH) effort of standardization, specifically regarding fast controller characteristics. The prototypes will be built using two different form factors, PXIe and ATCA, with the aim of comparing the implementations. The presented solution took into consideration channel density, synchronization, resolution, sampling rates and the needs for signal conditioning such as filtering and galvanic isolation. The integration of the two controllers in the standard CODAC environment is also presented and discussed. Both controllers contain an EPICS IOC providing the interface to the mini-CODAC which will be used for all testing activities. The alpha version of the FPSC is also presented.     

Daily stress variability, learned resourcefulness, regimen adherence, and metabolic control in Type I diabetes mellitus: Evaluation of a path model.

A model of daily stress and metabolic control in Type I diabetes was tested in which stress has dual effects on glycemic level: (1) direct, through psychophysiological mechanisms, and (2) mediated, through regimen adherence. Learned resourcefulness was postulated to moderate both effects. Two approaches to measuring daily stress were also compared: stress mean and variability. Daily stress and adherence were measured in 62 adult diabetics on 6 occasions over 2 mo, after which glycosylated hemoglobin levels were obtained. Stress had a direct association with metabolic control that was not mediated by adherence. Although learned resourcefulness failed to moderate this relationship, it did relate directly to metabolic control, in the unexpected direction. The variables combined to explain 37% of the variance in metabolic control. The utility of the intraindividual approach to daily stress measurement was supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)