Revision as of 14:48, 21 October 2014

Misc Questions

In no particular order, these are the questions pertaining to DAQ and its interface with off-line:

what is the low level DAQ file format/encoding (ROOT? binary?)
what schema does the content of DAQ files follow?
where is a diagram showing all the parts of the DAQ data stream with their names (millislice, microblock, tick, "trigger", etc)?
what is the start/stop criteria that defines the highest level "chunk" of data (e.g. a "trigger")?
how does this "chunk" correspond to a trigger for each expected trigger criteria?
what time-ordering is expected from data coming out of the DAQ, particularly between disparate sources (e.g. Wires/PDs)?
are we going to implement a "world clock" with 1 us resolution?
what unit of data "chunk" ("event") is required and desired for offline analysis?
what offline analysis decisions/limitations can we, as a collaboration, be comfortable "baking in" to this choice of unit?
how are DAQ data "chunks" (triggers) numbered? How are offline data "chunks" ("events") numbered?
what is the mapping from the former to the latter?
what changes to art and/or LArSoft are needed to accommodate the above answers?