PXI-based architecture for real time data acquisition and distributed dynamical data processing

This paper describes an architecture model for data acquisition systems based on compact PCI platforms. The aim is to increase real time data processing capabilities in experimental environments such as nuclear fusion devices (e.g. ITER). The model has these features: a) real time data acquisition: the system has been provided with real time capabilities, developing specific data acquisition kernel modules under Linux and RTAI, using COMEDI project drivers; b) multiprocessor PXI (PCI extension for instrumentation) architecture: the model makes possible to add one or more processing cards (in non-system slots) to each standard PXI chassis. Several real time software modules have been developed to allow the communication between the PXI controller and the processing cards. This way the system performance is not restricted to the PXI controller´s own performance. This model provides scalability to the system, adding or removing processing cards; c) real time acquired data distribution: with this model it is possible to define how to distribute, in real time, the data from all acquired signals in the system among the processing cards and the PXI controller; and d) dynamical data processing: a software platform has been developed to allow users managing dynamically their own data processing algorithms in the system. This means that users can start, stop, modify, and replace their data processing algorithms without disrupting neither the data acquisition process nor the rest of the data processing algorithms