In the context of DUNE 2x2 (and later, full ND-LAr) we need to be able to match up events between the TPC and and adjacent spectrometer (MINERvA for 2x2; TMS or ND-GAr for ND-LAr). Because the DAQs for those will not necessarily be run in a coordinated way (in particular, there is no reason to expect that event numbers will align, given the detectors will need to be started and stopped separately, and have different capabilities for how they can be triggered), the data stream itself needs to provide some way of matching them up.
This PR adds a simple mechanism for propagating basic info that can be used for matching. It supposes that the most fundamental unit is the "trigger"---the signal beginning of a readout. It carries: the time the trigger came, a trigger ID associated with it (probably the same as the event number, but is not forced to be), and a trigger "type" field that can be used independently for each detector. The expectation is that matching will primarily be done using the trigger time.
In the context of DUNE 2x2 (and later, full ND-LAr) we need to be able to match up events between the TPC and and adjacent spectrometer (MINERvA for 2x2; TMS or ND-GAr for ND-LAr). Because the DAQs for those will not necessarily be run in a coordinated way (in particular, there is no reason to expect that event numbers will align, given the detectors will need to be started and stopped separately, and have different capabilities for how they can be triggered), the data stream itself needs to provide some way of matching them up.
This PR adds a simple mechanism for propagating basic info that can be used for matching. It supposes that the most fundamental unit is the "trigger"---the signal beginning of a readout. It carries: the time the trigger came, a trigger ID associated with it (probably the same as the event number, but is not forced to be), and a trigger "type" field that can be used independently for each detector. The expectation is that matching will primarily be done using the trigger time.