The GLAST online software
Gamma-ray Large Area
Space Telescope
Luca Latronico
Glast Italia software meeting
Udine 31-31/1/2003
 what is the online software in GLAST
 LAT hardware and DAQ
 core software architecture (class hierarchy)
 DAQ/online roadmap: use and evolution of the
software
 tools (Python, Qt, Hippodraw)
 some tkr preliminary examples/results
 afternoon tutorial
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online software – what is it for?
Electronics
detector performance:
tracks, hits, events
Data AcQuisition:
•test LAT hdw
•calibration
•environmental data
monitoring (T,I,V)
•data taking
Required tools:
Drivers to electronics
Test scripts
User GUIs
Data analysis
Visualization tools
Online and Electronics Ground Support Equipment (EGSE)
Subsystems (TKR, CAL, ACD) – LAT Integration and Test
Mission operation – flight software
Our definition of online: DAQ and monitoring on the ground prior to launch
No interference with flight software developement …. but ….
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online software – how is it made
Online software:
Python scripts
Qt GUIs
HippoDraw
Low-level drivers
Compiled C code
hardware
Flight software
Compiled C code
Luca Latronico
Low-level drivers
Compiled C code
Glast italian software meeting, Udine 01/30/2003
GLAST Instrument: the Large Area Telescope (LAT)
Tracker
• Array of 16 identical
“Tower” Modules, each
with a tracker (Si
strips) and a
calorimeter (CsI with
PIN diode readout) and
DAQ module.
• Surrounded by finely
segmented ACD
(plastic scintillator
with PMT readout).
Grid
DAQ
Electronics
Luca Latronico
ACD
Calorimeter
Thermal
Blanket
• Aluminum strong-back
“Grid,” with heat pipes
for transport of heat
to the instrument sides
• high modularity
Glast italian software meeting, Udine 01/30/2003
GLAST Tracker Design Overview
• 16 “tower” modules, each with 37cm  37cm of active
cross section
One Tracker Tower Module
• 83m2 of Si in all, like ATLAS
• 11500 SSD, ~ 1M channels
• 18 x,y planes per tower
– 19 “tray” structures
• 12 with 3% r.l. W on top (“Front”)
• 4 with 18% r.l. W on bottom (“Back”) SuperGlast
• 3 with no converter foils (3-in-a-row L1T)
– Every other tray is rotated by 90°, so each W foil
is followed immediately by an x,y plane of
detectors
Carbon
• 2mm gap between x and y oriented detectors
thermal
• Trays stack and align at their corners
panel
• The bottom tray has a flange to mount on the grid.
• Electronics on sides of trays:
– Minimize gap between towers
Electronics
– 9 readout modules on each of 4 sides
• high modularity
Luca Latronico
flex cables
Glast italian software meeting, Udine 01/30/2003
Tracker tower read-out architecture
• 24 64-channels CMOS
VLSI (custom ASIC ) readout chips handle a single
detector layer
• data can shift left/right
with a read-out controller
(custom ASIC CMOS) at
each end at 20 MHz clock
frequency
• Fast-OR signals also move
l/r or in both directions
• A single dead chip can be
bypassed without losing
data from any other chips
• Complete 0-suppression
and formatting takes place
in the controller chips, i.e.
fully digital output
• The read-out controller
pass data down a tower in a
token-controlled protocol
Luca Latronico
simplified block diagram of the GLAST TKR readout
Glast italian software meeting, Udine 01/30/2003
Tracker front-end electronics
miniMCM
7 GTFE
2 GTRC
tray with full-size MCM
24 encapsulated FE
2 encapsulated RC
1 ladder bias circuit
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
LAT electronics hierarchy
Survival jargon
AEM : ACD Electronics Module
TEM : Tower Electronics Module
GEM : Global trigger Electronics Module
GASU : Global trigger ACD Signal distribution Unit
CC : Cable Controller
RC : Read-out Controller
FE : Front-End
GLT : GLobal Trigger
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
The LAT
registers
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online software hierarchy
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online software hierarchy
An xml schema file is loaded to pass the
hardware configuration and load the tree
of pointers:
lat = readSchema(‘SimpleTemSchema.xml')
Navigation of the hierarchy is done using methods
like down/up/node, e.g. TKR-FE5/layer3/CC2 :
myGTFE = lat.downTEM(0).downTCC(2).downTRC(3).downTFE(5)
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online software – accessing registers
 each register has:
mnemonics, serial nb, size
 Set() [Get()] looks for
mnemonics and set [reads] the
register value
 dataless commands are treated as
registers of zero size
e.g. access MODE register on FE5/layer3/CC2 :

myGTFE.MODE = 0x0

lat.downTEM(0).downTCC(2).downTRC(3).downTFE(5).MODE

mymode = lat.TEM[0].TCC[2].TRC[3].TFE[5].MODE
as for standard DAQ software
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online software – constraints, conversions
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
I&T test stand runtime environment
Finite State Machine framework
 user GUI
 handles hardware configuration
 run test scripts
 handles communication with
logger, database, data monitor
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
References / entry point
Core software development at SLAC:
http://www-glast.slac.stanford.edu/LAT/INT/ONLINE/Default.htm
Essential documents
TEM + ~anything downstream (GTCC, GTRC, GTFE)
LAT-TD-00605-D1 TEM Primer
Trigger
•GLAST LAT Test Stand Communications Interface (online web page –
look at MiniGLT section)
•LAT-TD-00606-D1 LAT Inter-module Communications
Specific nodes and test plans for TKR:
node
location
GTCC TEM
GTRC TMCM
GTFE TMCM
MCM*
TOWER
doc
LAT-TD-00605-D1 TEM Primer
LAT-TD-248
LAT-TD-247
LAT-TD-249
LAT-TD-191-02
LAT-SS152(level IV specs)
LAT-SS17(level III specs)
TKR specific tools – soon available at http://glastserver.pi.infn.it/glast
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Instrument integration and calibration plan
Subsystems acceptance, qualification, environmental tests
milestone
instrument
schedule
source
activity
Engineering
Model (EM)
4-trays TKR
1 full-tower CAL
no ACD
3-4/03
CR
VG 17MeV g
Calibrations
Calibration Unit
(CU)
4 full towers
5-6/04
e+
h
g
Calibrations +
science perf.
verification
Flight Unit (FU)
LAT (16 towers)
10/04
CR, VG
Calibrations +
science perf.
verification
Flight Unit (FU)
LAT (16 towers)
05
Flight Unit (FU)
LAT (16 towers)
05
spacecraft
integration
CR
airplane test
October 2006 - LAUNCH
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
The Engineering Model milestone
1 TKR module with 4 live trays (3 XY planes)
1 full scale tower CAL
Tower electronics
Calibrate the system
Charge injection
Cosmic rays
17.6 MeV photons
Timescale - february/june 2003
TKR commissioning :
• si sensors test
• ladder assembly and test
• tray production
• FE/RC/MCM production
• development of tools for system tests
Luca Latronico
(from I&T/SVAC)
Glast italian software meeting, Udine 01/30/2003
EGSE - Tower test setup
TEST JIG
will be used for EM and full tower tests on ground during I&T
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
The Engineering Model milestone – DAQ architecture
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
I&T test stand - DAQ hardware overview
• VxWorks
• low level drivers
VME
Proc
LV
CMD EVT XBRD
+28V
COM COM
PSA
TEM bias
Sensors+Read-out
ELX bias (both
TKR and CAL)
to CAL
GASU
cable
TRAY
TEM
TRAY
DAQ/Online • high level python interface (PyLAT)
Workstation • data analysis and monitoring
Read-out event rate 1KHz
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
I&T test stand - a picture
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Test stand – some more survival jargon
EM : Engineering Model
EGSE : Electronics Ground Support Equipment
TEM : Tower Electronics Module
PSA : Power Supply Assembly
GASU : Global trigger ACD Signal distribution Unit
XBRD : transition board, currently supplying the GASU-trigger and
PDU (Power Distribution Unit) functionalities
LCB : LAT Communication Board – currently implemented as the COM
card, will be a custom cPCI board to pulg into the VME processor
INTERFACE BOARD : temporary board to connect the TEM to the
MCM (same as the one used in the UCSC system, where it connects the
MCM directly to the COM card with NO TEM)
ITAR : International Traffic in Arms Regulations
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
I&T / flight DAQ architecture
Allowed independent EGSE/flight software development
Use of spacecraft communication protocols
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online tools – Qt GUIs
Set of C++ classes
Converted to Python with SIP/SWIG
Commercial version for development
Free version for learning
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Online analysis-visualization tools : HippoDraw
GUI-driven analysis tool by P. Kunz
Set of C++ classes
Java and Qt GUIs
Now providing python scripting
capabilities
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
The TKR subsystem point of view – DAQ ladder tests
Source profile
4
Source + Noise (1 Khz)
Source (100 Hz)
3.5
Counting rate (Hz)
3
2.5
2
1.5
1
0.5
0
63
127
191
Strip number
The source profile does NOT change when random noise triggers, obtained by lowering the threshold
on boundary channels, are added – the ladder and the read-out are fully efficient
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
The TKR subsystem point of view – DAQ ladder tests
Threshold Scan with
92
Sr source
1000000
64 chans FE1, SOURCE
64 chans FE1, NO SOURCE
100000
Counting Rate (Hz)
10000
1000
100
With source
10
1
0.1
Without source
0.01
0
10
20
30
40
50
60
70
Threshold DAC (Threshold range = 1, Bias voltage = 60 V)
• 50% rate point corresponds to median of the charge-release distribution
• assuming a plateau @ 400 Hz (which isn’t evident from the plot, but consistent with a rough
measurement performed with a Geiger) this turns out to be about 6fC ~ 40ke- ~> 1MIP
• deviations from effects like high charge release from slow electrons, charge sharing, inclined tracks
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Work plans for EM
Before delivery to I&T :
 suite of scripts for trays/mini-tower testing:
 hardware configurations
 dead channels (charge injection, b source scan)
 noise evaluation (threshold scans, counting rates / occupancy)
 library of TKR specific functions and test routines
 During I&T effort at SLAC
 same scripts inside standard run-time acquisition
 low level elx functional tests
 test grid:
 high level functional tests (load/read back – configure system)
 calibrations (dead chans – noise – ToT)
 run (17.6 MeV g reconstruction)
 low level tests in response to specific problems
 connection to SAS software
 Two people been at SLAC (Latronico, Baldini), one currently at SLAC
(Cohen-Tanugi), two students from Pisa
Luca Latronico
Glast italian software meeting, Udine 01/30/2003
Afternoon tutorial
Tutorial

Running an application from the RunControl

Python
PythonWin IDE
module browsing using the Python documenter: browse gLAT.py
and tkr_lib.py

Write a Qt GUI in python

HippoDraw for data analysis using a python script and the data
inspector
Luca Latronico
Glast italian software meeting, Udine 01/30/2003