Data aquisition system

SubDetector Progress

The CLOUD-DAQ is responsable for:

  • Instruments Integration
    • Network physical connection of the instruments
    • Software software deployment
  • Data aquisition and CLOUD Monitoring
    • Data Flow and Backup
    • Monitoring software plots of the most important parameters variance in quase-real time
  • Elog used to keep automatic and personalized records about the experiments conditions

The CLOUD-DAQ is divided into packages:

Description of the DAQ system:

Time Synchronization

The Time Synchronization package is responsible for the synchronization of the subsystems. In the experiment all the instruments will acquire data in an individual way. The data taking has to be synchronized in order to correlate the data during off-line physical analysis. The implementation of this synchronization was made using timestamps created by local clocks, that are synchronized by the time protocol NTP. The synchronization is done in the simulated infrastructure on the CERN-CLOUD DAQ server.

Storage and Monitoring of basic type and values

The Storage and Monitoring of basic types and values was projected to attend to the CLOUD monitoring needs. As a answer to this needs, it was chosen a system that already incorporated the acquisition of basic type data and a generalized display. On this choice part of the storing process was already implement. An implementation of a high performance scada system, much like PVSS, was chosen. This package called ZABBIX is open source and was used as the main software structure of the DAQ. Some programs were made using the interfaces of ZABBIX to make the connection to the instruments. These programs read the instruments data files and send the data to the ZABBIX server.

This part of the DAQ is operational, in the DAQ CLOUD server at CERN, in a simulated way and in a full way for some instruments like the Cosmic rays counter and the hodoscope. To complement the monitoring a set of customized plots were build, fully integrated in the ZABBIX web interface.

An interface was develop to set a standard way for producing the plots. The plots are being use now to make an offline application with the purpose of making offline plots and analysis.

Complex Object Storage

The Backup and Complex Object Storage is the part of the DAQ that stores and backup all the data. The data will pass through two paths in the DAQ, through ZABBIX server (database) and by file copy. In the first case, the MYSQL database, used beneath ZABBIX, will be incrementally backed up to a CERN ORACLE database. An application was developed to insert the SQL statements, that come form the MYSQL logs, into the ORACLE database. This was already used in June for tests. In the second case, the instruments data files will be copied to the DAQ server and at the end of the day, they will be put in CASTOR. The copy of the data files will be made by the protocol of RSYNC, this is yet to be done.

Run Control and Configuration

Online Data Processing

The Online Data Processing is an infrastructure in development, not yet implemented, to collect data from the mysql database or data files storage, provide this data to the algorithms and then put the results in the monitoring database.

Data Access

The Data Access, will provide the users with the access to the data in the monitoring database and in the data files storage. In the case of files, the technology used will be the RSYNC protocol. In the case of the monitoring database the offline application for plots, mentioned earlier, will be used.

Data Reconstruction and Analyses Framework

The Data Reconstruction and Analyses Framework is a framework of offline analyses that will be implemented in the future.

The instruments at CLOUD

The instruments discription is available at Instruments, with :
  • Computer node of the Instrument
  • Data to send to the Central DAQ
  • Time stamping
Topic attachments
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PNGpng DAQ.png r1 manage 2564.8 K 2009-10-14 - 14:37 UnknownUser Description of the DAQ system
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Topic revision: r21 - 2009-10-22 - AndreDavid
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