Dresden 2013 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 10: Instrumentation

HK 10.7: Talk

Monday, March 4, 2013, 12:30–12:45, WIL-A221

Design concepts and measurements of the CBM DAQ network — •Frank Lemke and Sven Schatral — Universität Heidelberg

In the context of the Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt a hierarchical structured data acquisition (DAQ) network is used to readout particle detectors over synchronized bidirectional links. Interconnects operate with unified connections using one special protocol (CBMnet) in the whole readout. Thereby no protocol conversion is required. Communication modules provided for various hardware devices are easy to insert into new ASICs or FPGAs. Thus, more and more devices can be equipped with these modules. This saves design time and enables usage of existing structures optimized for CBM requirements. Besides multiple supported FPGA platforms, the first front-end ASIC, the SPADIC, was developed and it has been completely tested. A second front-end detector ASIC with CBMnet, the STSXYTER, was submitted at the end of October, expanding the usage of CBMnet to further readout chains. Unbalanced line handling enables higher data rates with reduced wiring overhead. The current implemented universal readout controller board using a Spartan 6 FPGA offers the ability to synchronize and readout up to four front-end boards. The synchronization mechanism based on deterministic and simultaneous arrival of deterministic latency messages (DLM) in all front-end devices works with accuracy better than 2ns. Not only the synchronization, but also all other communication classes have been tested successfully.