PXI-based architecture for real-time data acquisition and distributed dynamic 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: 1) 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; 2) Multiprocessor PCI eXtensions for Instrumentation (PXI) Architecture: the model makes possible to add one or more processing cards (in nonsystem 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; 3) 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 4) Dynamic Data Processing: a software platform has been developed to allow users to dynamically manage their own data processing algorithms in the system. This means that users can start, stop, modify, and replace their data processing algorithms without disrupting the data acquisition process or the rest of the data processing algorithms.