On-Board Data Handling for the PAMELA Experiment

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On-Board Data Handling for the PAMELA Experiment

Ralf Wischnewski Roma2 DESY-Zeuthen
Alghero, 30.9.2002
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• The task
• Space requirements
• Pamela CPU PSCU
• On-board DAQ design
• Data downlink
• Status Summary

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The INSTRUMENT
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The Tasks (1)
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The Tasks (2)
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PAMELA STORAGE AND CONTROL UNIT

• CPU (ERC32 SPARC V7) 17 Mips _at_ 24MHz
• SRAM 4 Mbyte
• Boot PROM
• EEPROM 1 Mbyte
• 1553 Remote Terminal to Satellite CPU
• 64 Kb x 16 RAM buffer
• Logic ASIC which include PCMCIA
• bus controller Parallel System Bus
• Solid State Mass Memory 2 2 Gbytes
• Pamela Interface (PIF) DMA bus controller and
  TAM interface
• Telemetry Housekeeping board 32 outputs 78
  inputs
• DC/DC converter integrato da 27 V a 14.4 V 5.2
  V
• Quartz clock 1 ms

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PAMELA DAQ Schematics
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PAMELA DAQ Schematics
Detectors
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Data Downlink to S/C and Earth

• Science and HK data (1-2 GB) to be transfered
  from Pamela to Satellite MassMemory (gt100GB)
  every few hours.
• Asynchronous request from Master S/C-CPU.
• Downlink from S/C to earth during ground station
  passages (Moscow Sturup/Sweden) _at_ 320Mbps over
  a few minutes.
• Needs fast analysis for uplink response on next
  orbit.
• All operations based on pre-defined absolute
  time schedule, arbited from S/C and uplinked from
  Ground.

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Pamela Data PathS/C to Ground
MM S/C
DLink S/C
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PSCU Engineering Model
RAM (2x2 GB)
CPU, PIF, TMTC
DCDC
The PSCU is constructed in 2 phases by
LABEN/Milano 1. Engineering Model (EM),
currently under full test _at_ INFN 2.
Flight Model (FM), under construction _at_ LABEN
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PAMELA ENGINEERING MODEL

• Assembly of the Engineering Model (EM) is the
  major functionality and I/F test to be passed
  before the final Flight Model (FM) is build
• System compability test
• Mechan. electr. interface test
• Test procedure definiton for ground test
  equipment (EGSE).

Note The PSCU is (with Power Supply) the main
Interface between Pamela and the Satllite.
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PSCU-EM Tests

• Basic functionality test
• Trigger rate 80 Hz
• 1/10 evts transfered to CPU-RAM
• to simulate sampled event analysis
• Telecomand communication
• (1553 Bus)
• Write to PSCU MassMemory
• and download via TAM

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PSCU TEST EQUIPMENT

• Full functionality test of PSCU needs an
• Electrical Ground Support Equipment (EGSE),
• simulating all system interfaces
• power supply (27 V)
• Control Command (ON/OFF, RESET)
• bus 1553 for telecomands
• telemetry
• I-DAQ board to receive FE Comands and
• reply detector data in real time
• monitor for PSCU electrical/thermal status
• debugger and monitoring SW
• simulator for Housekeeping input
• event trigger simulation
• science data readout (TAM)

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PSCU TEST EQUIPMENT _at_ ROMA
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PSCU - ON-BOARD SOFTWARE

• RTEMS as Operation System
• (Real-Time Executive for Multiprocessor
  systems)
• multitasking
• preemptive or monotonic scheduling
• comunication zone and intertask synchronisation
• interrupt handling
• optional task interrupt priority
• dynamic memory allocation

• RTEMS is supported by ESA/ESTEC including Cross
  Compiler ERC32CC with
• GNU C compiler
• Linker, assembler, archiver etc.
• Standalone C-library
• RTEMS real-time kernel with ERC32 BSP
• ERC32 boot-prom utility
• Standalone simulator ERC32
• GNU debugger with ERC32 simulator DDD

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Main Functional Modes and Tasks
Overview of Pamela main functional modes and
parallel system tasks. Telecomands from S/C
Master CPU switch between operation modes.
Automatic-mode change is under implementation. TMT
C-Housekeeping, S/C 1553 I/F, Logging, Error
check and General Interrupt handling tasks are
permanentely active.
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Science data event managment chart
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BEAM TEST _at_ CERN SPS 5-12/06/2002
e _at_ 20-300 GeV p _at_ 300-350 GeV
PSCU Buffers are optimized for event size lt 16
kB.
Tracker data size (compressed).
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Second Level Trigger
Trigger on IDAQ-Board Fast DSP-rejection
algorithm for Background events, w/o PSCU.
Using AntiCoincidence Veto. But signal
rejection by back- scattering from
calorimeter. Calorimeter - particle
classification (non-interacting, hadronic,
em). TOF - n of hits per plane TRACKER - n of
clusters, no online reconstruction. Verificati
on with SPS/PS test beam data (2002).
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PAMELA DAQ - Summary

• Most components of the Pamela DAQ and Slow
  Control are ready for system test.
• CPU-EM in full test _at_ INFN CPU-FM in production
  _at_Laben
• Finalization of Pamela Slow Autonomous Control
  Procedures

• Next steps
• DAQ / FE-board system test with S/C-Simulator
  in Rome (12/2002)
• Deliver Pamela-EM to Russia for S/C EM test
  (1/2003)
• Integration of Pamela FM with FM-PSCU, physics
  test, delivery to Russia (5/2003).