The Sub-Event Buffer PCs are the 10 DAQ PCs connected to the readout crates converting the signals from the experiments for the various parts of the detectors.
There is one SEB per each crate:

  • SEB1-9 for the TPC crates * SEB10 for the:
  • PMT. note that the PMT data format is different than the TPC one, but is handled by a similar XMIT and its output is fairly similar to the TPC output from the XMIT.
  • Trigger - Trigger information is sent to SEB10 on one optical cable, plugged into a similar PCIe card as the controller module.
  • GPS card - SEB10 also has a GPS card. A GPS signal is sent to the trigger board to give us a map of frames and their time. This map is updated every second, and this information is sent along with the data to the EVB.

Disk Space on the SEBs

On the supernova stream we should get something around 50MB/s per seb, with the exception of seb06 which has higher rate (~100MB/s)
The current SEBs have 13 TB disk space for the SN stream.
Nowadays the SN data is saved for 24 h.