Data acquisition in the HERA-B and LHC era

Experiments are now being constructed to measure B decays at hadron storage rings. The primary B-physics goal of these experiments, the discovery and detailed measurement of CP violating asymmetries in B decay, will make extreme demands on the data acquisition (DAQ) and trigger systems. These demands will be met with multi-level pipelined DAQ systems. The architectural model adopted for the DAQ systems of these experiments is described in this article. The HERA-B DAQ will be one of the first such systems to be built and is used in this contribution as an example of the architecture. Important architectural issues and technological trends are also discussed.