Excellence in Detectors and Instrumentation Technologies

INFN - Laboratori Nazionali di Frascati, Italy  October 20-29, 2015
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Trigger and Data Acquisition and muon TOF measurement (DAQ_LAB)

CONVENER G. Mazzitelli (LNF), E. Pasqualucci (INFN-RM1)
TUTORS R. Gargana (LNF), F. Pastore (UCL), W. Vandelli (CERN)
LOCATION Bd. 48

Purpose of the DAQ_Lab is to learn how to build a simple trigger and DAQ system with some scalability feature from scratch by applying it to a simple experiment to measure the speed of cosmic muons.
Students will be splitted into two groups, 3 people each, in order to be able to efficiently work on all the parts of the system.

  1. Set-up preparation. Access to VME and preparation of debugging tools for boards. Trigger and trigger management. (day 1)
  2. State machines and stateless systems. Preparation of the experiment’s state machine and run control. Data Readout applications and data format. (day 2)
  3. Preparation of an event building system in push mode. Comparison with pull systems. Data flow manager. (day 3)
  4. User interface and error reporting. Operation and data monitoring. Performing the measure using the online monitoring system. (day 4)

At the end of each step we will also propose generic solutions for each of the exercises.

  1. Set-up preparation (E. Pasqualucci, G. Mazzitelli)

    2. A simple experimental set-up to read out a couple of scintillators, composed by a NIM crate containing trigger electronics and discriminators and a VME crate with a single board computer and some readout electronics is prepared. We will introduce the basics of VME readout and trigger and busy management via a VME interface board (with polling and, in case Corbo modules are available, via interrupts). We will also prepare simple debugging programs for the VME boards and use it to illustrate common behaviors of QDC and TDC.

  2. Readout and control part

    The second day will be dedicated to the control part, introducing the concept of state machine. We will introduce the concepts of daq environment and build a simple message system and framework to implement a finite state machine for our system. We will use the framework to implement data readout at VME level and a simple run control program.

  3. Distributed systems: event building and data flow management

    During this module we will try to make our system more scalable by writing an event builder. Eventually, we could use the two system in parallel and build common events. We will then try to implement a data flow manager and discuss scalability and push and pull architectures.

  4. User interfaces, online monitoring, final measurement

    Having a distributed system, we will need a graphical tool to efficiently communicate with it. We will partially build a run control user interface allowing to easily send commands to the system and to receive messages from it. We will also implement some simple operational monitoring with event counters. As a last step we will be an online data monitoring process with an histogram browser, allowing to make our measurement online and complete the experiment.

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