Overview and future developments of the FPGA-based DAQ of COMPASS

COMPASS is a fixed-target experiment at the SPS at CERN dedicated to the study of hadron structure and spectroscopy. Since 2014, a hardware event builder consisting of nine custom designed FPGA-cards replaced the previous online computers increasing compactness and scalability of the DAQ. By buffering data, the system exploits the spill structure of the SPS and averages the maximum on-spill data rate over the whole SPS cycle. From 2016, a crosspoint switch connecting all involved high-speed links shall provide a fully programmable system topology and thus simplifies the compensation for hardware failure and improves load balancing