Balloon Flight Planning

1
Balloon Flight Planning

• Roger Williamson
• June 8, 2000

2
SCOPE

• DAQ subsystem
• Detector Interfaces
• Balloon Command, Data, and Electrical
• Instrument Power Supplies
• Onboard Software
• Ground Support Equipment

3
Requirements

• There is a Balloon Flight Objectives document in
  preparation that will serve as a source
  document.
• Derived Requirements
• L1T Trigger at the environmental rate
• Event deadtime of less than 100 microsec
• Save data from all events
• Send subsample of events to ground realtime

4
Assumptions

• Balloon flight 1st week of Sept, 2001
• Use modified BTEM tower
• Downlink not sufficient for full bandwidth data
• Power from 28V batteries
• Command uplink and primary 28 V power supplied
  by gondola

5
Overview

• Onboard data storage requirement
• 1 kHz L1T average rate
• 1 kbyte/event(TBR) average event
• 10 hour total record time
• 1e31e336e3 36 Gbytes (need more)
• CPU processing load risk mitigation
• FIFO buffers permit full rate bursts if CPU
  readout/processing cannot keep up
• TKR FIFO 200 events 200 ms burst

6
Existing Hardware

• Tracker Interface
• No modification required
• Calorimeter Interface
• No change to readout interface
• Dead time hold off input to L1T --- or ---
• Use 100 microsecond hold off timer in CAL readout
  FPGA
• ACD Interface
• No modification required
• Front end noise fix required - Modification
• HSK readout software - Modification
• Additional joint testing

7
Existing Hardware

• Global Level 1 Trigger
• OR FPGA in ACD TEM
• Requires added functionality for balloon flight
• Dead time hold off - New
• Global live time counter - New
• Global L1T counter reset scheme - New
• Possibly other science requirements for trigger
  logic

8
Existing Hardware

• GPS Receiver
• Battery powered
• Provide RS-232 Interface
• Revise Software to include timestamp and position
• IDB --- Ethernet CISCO switch
• Cable Harness
• L1T cables
• Ethernet IDB cables

9
Existing Hardware

• SIU TEM
• GPS sync with L1TCNT
• Ethernet to BIU for command and downlink TM
• Fiberoptic link via CISCO switch for GSE

10
New Hardware

• Merge Detector TEMS into 1 VME chassis
• Use 21 slot VME chassis
• One Master CPU for data acquisition and control
• VME backplane BLT to speed up data acquisition to
  higher L1T rate
• Omit Ethernet packet building for most data
  packets
• Send 1(TBD) event per second to downlink (depends
  on bandwidth and event size)
• Accepts change to modified data flow hardware on
  daughter card or VME
• Add HSK and LRS (rate counter) readouts
• Add Onboard Storage using VME chassis

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New Hardware

• Balloon Interface Unit (BIU) simulates SC
• TEM type VME Chassis
• Ethernet to TEM (instead of 1553B)
• New interface to balloon system for commands
• BIU provides downlink telemetry subsystem
• Provided by NRL with downlink telemetry system

12
New Hardware

• Power switching/control
• Controls power to each TEM from 28VDC
• Balloon Discrete Commands
• 21 Slot VME chassis
• Power Supplies
• 110VAC changed to 28VDC
• Detector power supplies mounted and controlled
  via VME boards
• On/off control via commands
• Detector bias voltage setting via commands
• Monitor currents and voltages, in/out

13
New Hardware

• Packaging
• Cable Harness Existing New
• Mechanical - New

14
Housekeeping

• Temperature monitors
• ACD - 16 (TBR) places
• CAL - 16 (TBR) places
• TKR (Existing) 16 places
• BIU 16 (TBR) places
• Power Supply Voltages - 14 (TBR) places
• Power Supply Currents - 14 (TBR) places
• Strain gauges (TBR)

15
Ground Support Equipment

• Record and display variable length packets
• Displays
• Existing event real-time display
• Housekeeping monitors
• Status and software monitors
• Additional histograms
• Science displays
• Command web page - Modified
• Balloon interface simulator -
• 28 V power
• Command
• Data
• Ethernet fiber optic link to CISCO switch

16
Software

• Post Beam Test Cleanroom Software
• Ran at rates above 1 kHz for FIFO readouts with
  direct read from FIFO
• Detector control and test suites from Beam Test
  (TBR)
• Modify for BLT readout of FIFOs to provide higher
  speeds and more CPU margin for other tasks
• Variable length event packets

17
Options

• Hardware Data Transfer (to 128 Mbyte DRAM)
• New data push technique to move event data to
  DRAM
• CAL Zero Suppression
• FPGA hardware version
• TKR FPGA Zero Suppression
• Hardware suppression of no-hit headers
• TKR Rate Counters
• TREQ rates for each layer (TBR)
• Poisson Rate Generator for L1T (commandable rate)

18
Schedule (June 2001 Flight)

• July, 2000 Balloon Flight Requirements Review
• July, 2000 ACD Testing at GSFC
• July, 2000 PDR Hardware Software
• July, 2000 TKR TEM at Stanford, 2 weeks
  test/devel
• Sept, 2000 CDR
• Oct, 2000 Power System Fab, pkg, HSK,...
• Oct, 2000 GSE Release 1
• Oct, 2000 All TEMS at Stanford for software
  development
• Nov, 2000 ACD I/F Test at GSFC
• Dec, 2000 TKR I/F Test at UCSC
• Jan, 2000 CAL I/F Test at NRL
• Mar, 2001 Gondola I/F Test
• Mar, 2001 GSE Release 2
• Apr 1-15, 2001 Hardware Integration at SLAC
• Apr 16-May 16, 2001 4 weeks Software
  Integration at SLAC
• May 17 Ship to GSFC
• May 19 2 week Gondola Integration at GSFC
• June 1 4 week software test at GSFC
• Aug 1 Ship to launch site

19
ISSUES

• L1T maximum trigger rate
• MC data simulation
• Data Flow Requirement
• Onboard Storage
• Trigger design
• Downlink bandwidth
• Schedule staffing
• Plan for modified data flow and trigger system

20
ISSUES

• ACD HSK readout debug
• ACD noise
• Power supply plan
• Onboard software plan

21
WBS