1. GLAST June 8, 2000, P. Roger Williamson, BFP - 1 Balloon Flight Planning Roger Williamson June 8, 2000

2. GLAST June 8, 2000, P. Roger Williamson, BFP - 2 SCOPE DAQ subsystem –Detector Interfaces –Balloon Command, Data, and Electrical –Instrument Power Supplies Onboard Software Ground Support Equipment

3. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 5 Overview Onboard data storage requirement –1 kHz L1T average rate –1 kbyte/event(TBR) average event –10 hour total record time –1e3*1e3*36e3 = 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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

11. GLAST June 8, 2000, P. Roger Williamson, BFP - 11 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 13 New Hardware Packaging Cable Harness – Existing + New Mechanical - New

14. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 18 Schedule (June 2001 Flight) July, 2000Balloon Flight Requirements Review July, 2000ACD Testing at GSFC July, 2000PDR Hardware & Software July, 2000TKR TEM at Stanford, 2 weeks test/devel Sept, 2000CDR Oct, 2000Power System Fab, pkg, HSK,... Oct, 2000GSE Release 1 Oct, 2000All TEMS at Stanford for software development Nov, 2000ACD I/F Test at GSFC Dec, 2000TKR I/F Test at UCSC Jan, 2000CAL I/F Test at NRL Mar, 2001Gondola I/F Test Mar, 2001GSE Release 2 Apr 1-15, 2001Hardware Integration at SLAC Apr 16-May 16, 2001 4 weeks Software Integration at SLAC May 17 Ship to GSFC May 192 week Gondola Integration at GSFC June 14 week software test at GSFC Aug 1Ship to launch site

19. GLAST June 8, 2000, P. Roger Williamson, BFP - 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. GLAST June 8, 2000, P. Roger Williamson, BFP - 20 ISSUES ACD HSK readout debug ACD noise Power supply plan Onboard software plan

21. GLAST June 8, 2000, P. Roger Williamson, BFP - 21 WBS