FELIX and SW ROD Commissioning of the New ATLAS Readout System

After a successful period of data-taking concluded in 2018, the ATLAS experiment is being upgraded with the goal of consolidating and improving its good physics performance. The upgraded detector systems will be complemented by a new readout chain with main components: the Front-End Link eXchange (FELIX) and the Software ReadOut Driver (SW ROD). The FELIX system is comprised of commodity servers equipped with one or more FPGA-based PCIe cards and a high speed network interface. Each FELIX node acts as a router between the detector front-end custom links and the switched network. Commodity servers connected via the network constitute the SW ROD infrastructure. Each SW ROD node runs a multi-threaded software tasked with data aggregation, buffering, detector-specific processing, and routing to the online data filter. This presentation covers the commissioning of the FELIX and SW ROD for the restart of the detector operations scheduled for early 2022.