Wuppertal 2015 – wissenschaftliches Programm

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T: Fachverband Teilchenphysik

T 38: Postersession

T 38.5: Poster

Dienstag, 10. März 2015, 13:00–13:45, Foyer Ebene G.10

New COMPASS DAQ — •Yunpeng Bai and Igor Konorov — James Franck Strasse 1, 85748 Garching

This contribution focuses on the deployment and first results of the new FPGA-based data acquisition system (DAQ) of the COMPASS experiment. Since 2002, the number of channels increased to approximately 300000, trigger rate increased to 30 kHz; the average event size remained roughly 35 kB. In order to handle the increased data rates, the new DAQ system with custom FPGA based data handling cards (DHC) had been decided to replace the event building network. The DHCs are equipped with 16 high speed serial links, 2GB of DDR3 memory with bandwidth of 6 GB/s, Gigabit Ethernet connection, and COMPASS Trigger Control System. It uses two different firmware versions: multiplexer and switch. The multiplexer DHC can combine 15 incoming links into one outgoing, whereas the switch combines 8 data streams from multiplexers and using information from look-up table sends the full events to the readout engine servers equipped by spillbuffer PCI-Express cards that receive the data. Both types of DHC can buffer data which allows to distribute the load over the cycle of accelerator. For the purposes of configuration, run control, and monitoring, software tools are developed. Communication between processes in the system is implemented using the DIM library. The DAQ is fully configurable from the web interface. New DAQ system has been deployed for the pilot run starting from the September 2014. In the poster, the preliminary performance and stability results of the new DAQ are presented and compared with the original system in more detail.