N + 1 redundancy on ATCA instrumentation for Nuclear Fusion

The role of redundancy on control and data acquisition systems has gained a significant importance in the case of Nuclear Fusion, as demanding security and high-availability requirements call for redundancy to be available. IPFNʹs control and data acquisition system hardware is based on an Advanced Telecommunications Computing Architecture (ATCA) set of I/O (DAC/ADC endpoints) and data/timing switch modules, which handle data and timing from all I/O endpoints. Modules communicate through Peripheral Component Interconnect Express (PCIe), established over the ATCA backplane and controlled by one or more external hosts. The developed hardware modules were designed to take advantage of ATCA specificationʹs redundancy features, namely at the hardware management level, including support of: (i) multiple host operation with N + 1 redundancy – in which a designated failover host takes over data previously assigned to a suddenly malfunctioning host and (ii) N + 1 redundancy of I/O and data/timing switch modules. This paper briefly describes IPFNʹs control and data acquisition system, which is being developed for ITER fast plant system controller (FPSC), and analyses the hardware implementation of its supported redundancy features.