Detector Dependent Unit (DDU)
The DDU resides in the FED crate located inside the underground
counting house USC55.
Each DDU receives DAQ data via optical links from 15 DMB's. The 15 DMB's correspond to chambers contained in a 20 degree wegde slice of one of the two EMU endcaps. The DDU buffers, formats and sends the data via SLINK to the Data Concentration Card (DCC) which merges data from several DDU's and sends the merged data via SLINK to the central DAQ system. Full error checking and reporting is also carried out on the DDU.