µLAN DATA ACQUISITION OVERVIEW

Setup

The fall 2003 µLan DAQ is designed to provide both readout and processing of data from four multihit TDCs (CAENs) and one Waveform Digitizer (WFD) that instrument the µLan scintillator tiles and beam counters respectively. The data acquisition also provides the control and monitoring of the high voltage, flight simulators, beamline elements and data storage.

The data acquisition hardware consists of a local network of three frontend processors (FE03 - FE05), one backend processor (BE01), and one mass storage processor (TB01). FE03 provides the readout for a single 6U VME crate containing the four CAEN modules and FE04 provides the readout and processing for a single 9U VME crates containing the WFD. FE05 is devoted to the control and the monitoring of the high voltage units and the flight simulator modules. The DAQ is based on the MIDAS data acquisition package. The frontend components are one CAEN frontend process for CAEN readout (running on FE03), one WFD frontend process for WFD readout (running on FE04), and separate high voltage, flight simulator, and beamline processes for slow control (running on FE05). The CAEN frontend and WFD frontend send their data to the backend processor BE01 which assembles these event fragments into Midas events using the midas event builder. In addition slow control events are periodically stored to record the status of the high voltage, flight simulators and beamline elements. BE01 also writes the events to a local disk using the Midas data logger and to the LT0 archive using the Midas lazy logger.