16 Integration of Detectors into a Large Experiment: Examples from ATLAS. . .
741
CERN
computer
centre
Event rate
~200 HZ
Local
storage
[5 nodes]
Event
building
[100 nodes]
Event
filter
[1800 nodes]
L2
[500 nodes]
Data
Control
Control
[20 nodes]
Monitoring
[32 nodes]
File servers
[100 nodes]
Multi-layered control network
[connections to all nodes]
Readout
drivers
Readout
drivers
Multi-layered data network
Dataflow manager
L2 supervisors
Events pulled: L2 75 kHz, event building 3.5 kHz
Regions of interest
Event data fragments
Data requests
Data requests
D
a
t
a
r
e
q
u
e
s
t
s
Surface building
USA15
Readout
systems
148 nodes
Central trigger
processor
Detector
specific frontend electronics
Data from events
accepted by L1 trigger
~1574 Readout
links
Calorimeter trigger
Muon trigger
L1 trigger
Events pushed at 75 kHz
Region-of-interest information
Rol
builder
Custom links
Readout links
Gigabit ethernet
Fig. 16.16
Block diagram of the ATLAS trigger and data acquisition system. Also shown are the different components of the dataflow