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Adding/Updating Triggers

Adding new triggers to the DAQ systems is easy but can have dire consequences if done improperly and can impact the ability of the experiment to collect data. The following procedures are the MINIMUM set of requirements that need to be met before a trigger is added to the system. In many cases, authors of triggers will be asked to perform additional studies and provide additional supporting documentation.

All Trigger Changes

All trigger changes are required to be accompanied by the following supporting information and documentation.

  1. Technical Note stored in Nova-DocDB describing in detail the trigger. This should include the physics motivation for the trigger, description of the algorithms and flow of the trigger logic, plots detailing the performance of the selection.
  2. Projected rates (decisions issued and bandwidth) for the trigger determined by using recent zero-bias 5 ms readout data from the detector/detectors on which the trigger will run.
    1. Rates must be presented as a function of tunable parameters in the algorithms
    2. Rates must be presented in Hertz
    3. Rates must include the data bandwidth (i.e. rate * event size)
  3. Efficiency projects for the trigger determined by using recent Monte Carlo simulations of the detector/detectors on which the trigger will run and based off of the processes the trigger is designed to detect.
    1. Efficiencies must be presented as a function of tunable parameters in the algorithms
  4. Purity projections for the trigger determined by using recent Monte Carlo background simulation or (as appropriate) zero bias data from the detector/detectors that the trigger will run on.
    1. Purities must be presented as a function of tunable parameters in the algorithms

New Triggers

New triggers require additional infrastructure/configurations to be added to the DAQ. The following are the steps that need to be taken to enable a new trigger:

  1. An entry/entries must be allocated in the trigger tables for the trigger
    1. Contact A.Norman () for trigger allocations and assignments
    2. The daqdataformats library within the DAQ must be updated and rebuilt
      1. Entries must be made in TriggerDefines.h
      2. Entries must be made in TriggerDefines.cpp
    3. The Global trigger must be made aware of the new trigger
      1. Entries in the GtDataTrig.cpp for TrigNameMap and ValidTrigTypes
      2. The Global trigger must be rebuilt
    4. Add configuration entries into the global trigger corresponding to the trigger
      1. Include prescale values
      2. Include throttle values
    5. An entry should be added to the Trigger Scalar configuration files for the detector configurations where your trigger will run. It should include the nominal trigger rate envelopes.
      1. Update the entries corresponding to the total trigger rates to reflect new projected system rates.

Existing Triggers

Existing triggers that require a change (algorithm or configuration) must follow the following steps:

  1. Update configuration entries into the global trigger corresponding to the trigger
    1. Include prescale values
    2. Include throttle values
  2. Update the Trigger Scalar configuration files for the detector configurations where your trigger will run to reflect the nominal trigger rate envelopes.
    1. Update the entries corresponding to the total trigger rates to reflect new projected system rates.