experimental facilities division ornl daq system interfaces neutron science software workshop oct...
TRANSCRIPT
Experimental Facilities Division ORNL
DAQ System Interfaces
Neutron Science Software Workshop
Oct 13, 2003
Rick Riedel
Experimental Facilities Division ORNL
Preprocessor
Detector Electronics
Detectors
PT0 Dis. Module
Chopper Dis. Module
Slow Controls
Timing Module
DAS System Diagram
Data/File Server
Control Computer
F.C. SwitchGbit Switch
Firewall
2G optical
1G copper
Experimental Facilities Division ORNL
“Black Box” View
• Data Source provider.– Data sets could be as large as 35Gbytes– SNS to generate 130 Gbytes/day…
26Tbyte/year.– Histogrammed or event mode
• Command consumer. – Python scripts embedded in XML requests.
Experimental Facilities Division ORNL
Feedback Requirement
AnalysisPC, Cluster,
Distributed Domain
Data/File Server Firewall
Python ScriptData (live,background,normalization)
Experimental Facilities Division ORNL
External Interfaces
• Firewall– “Live” data via internet (low bandwidth).– Python scripting file gateway – Firewall
• Data/File Server– File based objects– “Live” data (high bandwidth)– Read Access Only– Short term (as defined in DAS requirements)
Experimental Facilities Division ORNL
Remote Access--Firewall
• Availability is controlled by instrument scientist.
• Html (web page) controlled via password and at control computer.
• Remote Desktop or VNC portal. Port controlled via password.
Experimental Facilities Division ORNL
Data/File Server
• A file server (RAID 0/1) handles data access
• Pre-nexus format—current run
• Nexus format—completed runs.
• Data mining database input( to current Oracle database server)
• Handles backups
Experimental Facilities Division ORNL
Data Modes
• Standard=Histogram,
• PulseMode = Events identified with time stamp and pulse number. Allows cross correlation with ancillary data.
Experimental Facilities Division ORNL
Histogramming—Loss of Pulse Information
Neutron Events
TOF
X,Y
Counts
Time, E, Q, d
Pixel Spectrum
T.O.F., Space bins
Frame n+1
Frame n
Experimental Facilities Division ORNL
Pulse Mode—Retains Pulse Information. Allows use of correlation
techniques.
Neutron Events
TOF
X,Y
Frame n+1
Frame n
+Pulse Stamp
+Pulse Stamp
Chopper Phase,MagneticField, etc.
Chopper Phase,MagneticField, etc.
AncillaryData
+Pulse Stamp
+Pulse Stamp