glast large area telescope: electronics, data acquisition & flight software electronics

GLAST LAT Project DOE/NASA Peer Critical Design Review, March 19-20, 2003

G. Haller 4.1.7 Electronics V5 1

GLAST Large Area Telescope:GLAST Large Area Telescope:

Electronics, Data Acquisition & Flight Software Electronics

Gunther HallerStanford Linear Accelerator CenterManager, Electronics, DAQ & FSWLAT Chief Electronics Engineer

[email protected](650) 926-4257

Gamma-ray Large Gamma-ray Large Area Space Area Space TelescopeTelescope



Electronics OutlineElectronics Outline

• Overview• Team• Front-End Electronics• Tower Electronics Module

– GLAST Calorimeter Cable Controller ASIC (GCCC)– GLAST Tracker Cable Controller ASIC (GTCC)

• GAS Unit• GLAST Global Trigger Controller (GLTC)• SIU/EPU Crate

– LAT Communication Board– Spacecraft Interface Board– Processor

• Spacecraft Interface• Verification & Test• Testbed • Summary



LAT Electronics (Signals)LAT Electronics (Signals)

ACD

ACD

ACD

GASBoard P

EPUP0

To SC PScience Data

0 1 11

EPUP1

EPUR

SIUR

SIUP

TEM 0

CAL

TKR

Command Response UnitGlobal TriggerEvent Builder

ACD Electronics Module

GASBoard R

TEM 15

CAL

TKR

TEM 7

CAL

TKR

TEM 8

CAL

TKR

To SC RScience Data

Filtering Software

Command Response UnitGlobal TriggerEvent Builder

ACD Electronics Module

Command/Control/Monitor

Software

To SC P/RMIL1553/Discretes

From SC P/R1 PPS/GRB

Alert

GAS UnitPrimeRedundant

• TKR: Tracker

• CAL: Calorimeter

• ACD: Anti-Coincidence Detector

• TEM: Tower Electronics Module

• EPU: Event Processor Unit

• SIU: Spacecraft Interface Unit

• GAS Unit: Global Trigger-ACD-Signal Distribution Unit



LAT Electronics (Power)LAT Electronics (Power)

ACD

ACD

ACD

PDUBoard P

EPUP0

SC MainFeed P

0 1 11

EPUP1

EPUR

SIUR

SIUP

TEM 0

CAL

TKR

Monitoring and PowerDitribution

PDUBoard R

TEM 15

CAL

TKR

TEM 7

CAL

TKR

TEM 8

CAL

TKR

Monitoring and PowerDistribution

SC SIU RFeed

PDUPrimeRedundant

SC SIU PFeed

SC MainFeed R

GASUDAQ P

GASUDAQ R

ACD PSP

ACD PSR

GASU

• TKR: Tracker

• CAL: Calorimeter

• ACD: Anti-Coincidence Detector

• TEM: Tower Electronics Module

• EPU: Event Processor Unit

• SIU: Spacecraft Interface Unit

• GAS Unit: Global Trigger-ACD-Signal Distribution Unit

• PDU: Power Distribution Unit*

* PDU is presented separate in Power System presentation



TeamTeam

• Manager– Gunther Haller, SLAC

• Flight Software Lead– JJ Russell, SLAC

• DAQ System Lead– Mike Huffer, SLAC

• Mechanical-Thermal Lead– Dave Nelson, SLAC

• Power-EMI Lead– Dave Nelson, SLAC

• EGSE Lead– Mike Huffer, SLAC

• I&T Lead– Dave Nelson, SLAC

• Mission Assurance Lead– Darren Marsh, Nick

Virmani (SLAC, Swales)• Manufacturing Lead

– Jerry Clinton, SLAC

• Flight-Software Team: see FSW presentation

• Front-End Simulator– Mark McDougald,

SLAC• Parts

– Mark Freytag, SLAC• Harness

– Dave Nelson, Mark Freytag, SLAC

• Packaging – Jobe Noriel, SLAC

• ASIC & Board Analysis– Dieter Freytag, Oren

Milgrome, SLAC

• TKR sub-system electronics– Manager: Robert

Johnson, UCSC– EE: Dave Nelson,

SLAC• CAL sub-system electronics

– System Manager: Neil Johnson, NRL

– EE: Jim Ampe, NRL• ACD sub-system electronics

– Manager: Dave Thompson, GSFC

– EE: Glenn Unger, GSFC

• Power Distribution Unit– Patrick Young, SLAC

• GAS Unit– Joszef Ludvig, SLAC

• TEM DAQ Module– Leonid Sapozhnikov, SLAC

• Tower Power Supply– Vendor (Oversight: Dave Nelson,

SLAC)• Spacecraft Interface Board

– Michael Lovellette, Greg Clifford, Dennis Silver (NRL & Silver Engineering)

– Software: Dan Wood (NRL)• Crate Backplane

– Robert O’Leary, SLAC• Crate Power Supply Board

– Robert O’Leary, SLAC• LAT Communication Board

– Sandra Frazier, SLAC• GLAST Tracker Cable Controller ASIC

– Leonid Sapozhnikov, Noman Ahmed, SLAC

• GLAST Calorimeter Cable Controller ASIC

– Leonid Sapozhnikov, Noman Ahmed, SLAC

• GLAST Global Trigger ASIC– Joszef Ludvig, Noman Ahmed,

SLAC



Tracker ElectronicsTracker Electronics

• TKR sub-system electronics • Si-Strip Detectors• 24 GTFE (GLAST Tracker Front-End) ASIC (1,536 signal channels)• 2 GTRC (GLAST Tracker Readout Controller) ASIC• MCM (Multi-Chip Module) • Flex-cables

• Presented in tracker sub-system CDR

GTFE ASIC

GTRC ASIC



Calorimeter ElectronicsCalorimeter Electronics

• CAL sub-system electronics• Diodes• 48 GCFE (GLAST Calorimeter Front-End) ASIC• 4 GCRC (GLAST Calorimeter Readout Controller) ASIC• AFEE (Analog Front-End Electronics) board

• Presented in calorimeter sub-system CDR

GCFE ASIC

GCRC ASIC



ACD ElectronicsACD Electronics

• ACD sub-system electronics• PMT’s• 18 GAFE (GLAST ACD Front-End) ASIC• 1 GARC (GLAST ACD Readout Controller) ASIC• FREE (Front-End Electronics) board• High-Voltage Supply board (not shown)

• Presented in ACD sub-system CDR

GAFE ASIC GARC ASIC



Tower Electronics DAQ ModuleTower Electronics DAQ Module

• Main DAQ module, one on each tower– Controls and reads out data from

TKR MCM and CAL AFEE front-end electronics

– Zero-suppresses CAL event data– Buffers events in cable ASIC FIFO’s– Assembles CAL and TKR event

fragments to tower event – Transmits data to GASU– Contains monitoring and low-rate

science circuits– LVDS interface to front-end

electronics and GASU– Hardware with software controlled

configuration and mode registers• CAL ICD: LAT-SS-00238• TKR ICD: LAT-SS-00176• TEM ICD: LAT-SS-00363

Trigger Controller

Control, Event & HSK SignalsPower

Power from TEM PS Module

TKR (8 cables)

Trigger

TKR Cable ASIC

CAL Cable ASIC

CAL (4 cables)

Common Controller

Power to TEM Elex

Trigger signals to/from Global

Trigger on GAS Unit

Control & HSK signals from/to SIU, Event data to EPU,

all via GAS Unit



Tower Electronics DAQ Module (Con’t)Tower Electronics DAQ Module (Con’t)

• Engineering Model with full functionality and interfaces as flight has been used extensively in 18 copies in the field, controlled and readout with real-time software from the FSW group, and I&T software from the I&T group

• Not just tested in TEM test-setup at SLAC, but more importantly fully integrated in set-ups with real sub-system electronics

– at NRL and at SLAC with CAL electronics– In Italy and at SLAC with TKR electronics– At SLAC, NRL with DAQ electronics

• Flight Model with 8 GTCC and 4 GCCC ASIC, plus 2 ACTEL’s: design finished, ready for layout/fabrication

• LAT-TD-00605



Tower Electronics Module GCCC ASICTower Electronics Module GCCC ASIC• GLAST Calorimeter Cable Controller (GCCC) ASIC

– TEM interface to calorimeter AFEE• Configuration and readback data• Trigger and event data handling• Log suppression algorithm• Event buffers

– Contains • Two 64x16 FIFO’s• Three 128x16 FIFO’s• Core Logic• LVDS drivers/receivers

– VHDL code compiled into XILINX FPGA, is used on TEM’s which are operating with CAL electronics

– ASIC in fabrication, expected April 25– LAT-TD-01549

LVDS IO

CORE

FIFO

GCCC



Tower Electronics Module GTCC ASICTower Electronics Module GTCC ASIC• GLAST Tracker Cable Controller (GTCC) ASIC

– TEM interface to tracker MCM’s• Configuration and readback data• Trigger and event data handling• Data reformatting• Event buffers

– Contains • Two 64x16 FIFO’s• Three 128x16 FIFO’s• Core Logic• LVDS drivers/receivers

– VHDL code compiled into XILINX FPGA, is used on TEM’s which are operating with CAL electronics

– ASIC in fabrication, expected April 25– LAT-TD-01550

LVDS IO

CORE

FIFO

GTCC



Design & Verification for GCCC/GTCCDesign & Verification for GCCC/GTCC

VHDL

Simulation

Netlist

Automatic: Layout, Place&Route

CompareLayout: Add IO and LVDS. Result: Complete Chip Layout

Automatic: Generate Schematic

Manual: Schematic of IO, LVDS

Simulation: Spice

Full Chip Schematic

Netlist

Netlist w/o Parasitics Netlist with Parasitics

Full-Chip Simulation with Synopsys

Full-Chip Simulation with Synopsys

Full-Chip Compare/Verification

Fabrication

Test

Stress & Timing Analysis

Flight-Model Status 3/03



GAS Unit (Signal Distribution and Trigger)GAS Unit (Signal Distribution and Trigger)

EventBuilder

P

GlobalTrigger

P

CMD-Resp.Unit P

ACD

ACD

ACD

ACD EMP

GASBoard P

EPUP0

0 1 11

EPUP1

EPUR

SIUR

SIUP

ACD EMR

TEM 0

CAL

TKR

EventBuilder

R

GlobalTrigger

R

CMD-Resp.Unit R

GASBoard R

TEM 15

CAL

TKR

TEM 7

CAL

TKR

TEM 8

CAL

TKR

GAS Unit

Control,Commanding

Command-ResponseTrigger

• Uses GLTC ASIC to receive LVDS signals and to logically mask and combine 228 ACD trigger signals

• Global Trigger controller– Combines trigger inputs from

TKR, CAL, ACD and makes trigger decision

– Distributes trigger message with target CPU for event, time-stamp, event-number, and trigger type to sub-systems

– Total time from particle in detector to receipt of trigger accept signal: 2 sec

• Command Response Unit– Distributes control from SIU to

TEM’s, GLT, ACD EM, EB– Transmits readback data from

TEM’s, GLT, ACD, EB to EPU’s• Hardware with software controllable

configuration & mode registers– GLT ICD: LAT-TD-01545– CMD-Response ICD: LAT-SS-

00461; LAT-TD-00606• One prime and one redundant DAQ

board



GAS Unit (ACD EM & Event Data)GAS Unit (ACD EM & Event Data)

EventBuilder

P

GlobalTrigger

P

CMD-Resp.Unit P

ACD

ACD

ACD

ACD EMP

GASBoard P

EPUP0

To SC PScience

Data

0 1 11

EPUP1

EPUR

SIUR

SIUP

ACD EMR

TEM 0

CAL

TKR

EventBuilder

R

GlobalTrigger

R

CMD-Resp.Unit R

GASBoard R

TEM 15

CAL

TKR

TEM 7

CAL

TKR

TEM 8

CAL

TKR

GAS Unit

To SC RScience

Data

Filtering Software

PrimeRedundant

• Uses GLTC ASIC to convert LVDS to CMOS signals and to logically mask and combine 228 ACD trigger signals

• ACD EM– Controls and reads out data

from ACD front-end electronics– Buffers events– Assembles 12 ACD event

fragments to ACD event – Transmits data to EB– Contains monitoring circuits

• Event Builder– Receives event fragments from

TEM’s, AEM, and GLT at up to 10 KHz rate

– Builds LAT event and transmits to EPU’s/SIU’s at up to 10 KHz rate

– Receives CPU data, forwards to other CPU’ s or to SC (science data interface)

• Hardware with software controllable configuration & mode registers

– ACD ICD: LAT-SS-00363– AEM ICD: LAT-TD-00639– EB ICD: LAT-TD-01546

• One prime and one redundant DAQ board



GAS Unit (Con’t)GAS Unit (Con’t)

• GLAST Global Trigger Controller (GLTC) ASIC– LVDS receivers for ACD veto and CNO trigger

signals– Maskable logical-OR function of ACD trigger

signal– Handles 18 input signal channels– Contains

• Core Logic• LVDS receivers

– First version ASIC was received in Dec 02– Fully working, is flight design– Flight quantity is on shared LAT wafer-run

expected back end of March 03

– LAT-TD-0148

• Engineering Model with partial functionality and interfaces as flight has been used in several copies in the field, controlled and readout with real-time software from the FSW group, and I&T software from the I&T group

• ACD EM at SLAC and GSFC, with real ACD front-end electronics• Trigger input signal received and trigger accept message generated via SLAC COM-

module (either CAL, TKR, and ACD programmed) • Flight Model with 14 GLTC and 9 ACTEL’s: design finished, in layout/fabrication



SIU/EPU CrateSIU/EPU Crate

PCIInterface

SIB

MIL1553*

PowerControl*

EEPROM

BackPlaneHeater

Control*

PCIInterface

Event Data

Command-Response

FIFO

LCB

28-V DC/DC

Power-OnReset

LVDS ConvertionPSB

3.3V/5V

CPU

PCIInterface

Power PC

Discrete I/O

VCHPHeater Box

PDU

SpacecraftMIL1553

GASU

SpacecraftPower

GASU

SpacecraftDiscretes

SystemClock

GASU

• Spacecraft Interface Board (SIB)– EEPROM– MIL1553 Communication with

spacecraft*– Power Control of PDU/GASU power

switches in PDU*– Power Control of VCHP switches in

heater box*• LAT Communication Board (LCB)

– Communication with GASU• Commanding• Read-back Data• Housekeeping Data• Event Data

• Power Supply Board (PSB)– 28V to 3.3V/5V conversion– Power-On Reset– LVDS-CMOS conversion of

spacecraft discretes*– System clock to GASU

• CPU Board– Processor– IO of level-converted SC discretes

• Backplane– passive

* Only used in SIU crate



LAT Communication BoardLAT Communication Board



LAT Communication Board (Con’t)LAT Communication Board (Con’t)

• PCI-interface engineering model in operation since early 03 (has PMC connector)

• Flight Model has cPCI connector: design finished, scheduled to be in layout/fabrication 4/03

• ICD: LAT-TD-00860



Spacecraft Interface BoardSpacecraft Interface Board

• Designed/implemented by Silver Engineering (Dennis Silver, Greg Clifford) under contract by NRL

– Driver by Dan Wood/NRL

• Engineering model is in test since mid 02

– 6U cPCI PCB Format

– Uses J1 of cPCI

– 12 Layer Polyimide Construction

– 4 Chassis GND Planes

– 3 Power and Ground Planes

– 5 Routing Layers

– 65 Ohm Controlled Impedance Signals

• Flight Model adds npn transistors for heater control

– Schematic updated

– Waiting for layout modification

• ICD: LAT-SS-01539

cPC

I

cPCI SHARED ADDRESS/DATA/CTRL

SRAM32K x 16

FPGA

SµMMITUT69151DXE

1553 A BUS

1553 B BUS 48MHZ

ACTEL RT54SX32S(208PIN)

PCI CoreTarget Only

VR +3.3V +2.5V

33MHZ32bit3.3V

SUMMIT CTRL/STAT/SEL/ARB

47

64

44

4MBEEPROM

/224MHZ

+5VPOR

+5VPOR

LOCAL BUS

4MBEEPROM

(12)

(12)

(4)

(4)

HeaterRegister

10TO PRIMARYPDU/GASU

TO REDUNDANTPDU/GASU

TO LEFT HEATERCONTROL BOX

TO RIGHT HEATERCONTROL BOX

EXT_POR_L

(4)PDU SPARE



ProcessorProcessor

• BAe750 compact PCI board• 750 class Power-PC• 240 MIPS at 133 Mhz, • Less Than 12W• 128 Mbytes main memory• 256 Kbytes SUROM • Total Dose > 100 kRad (Si),

Latchup Immune, SEU Rate < 1E-5 Upsets/processor-day @ 90% GEO

• VxWorks real-time operating system

– LAT ordered prototype, was received Spring 02

– Since then used for software development at NRL

• Boot-code• Bench-mark for LAT filtering

code• Test with SIB MIL1553 prototype

– Same board selected by GLAST spacecraft contractor

• To be ordered April 03



LAT Spacecraft InterfaceLAT Spacecraft Interface

Power

SPACECRAFT

MIL1553

LAT

1 PPS

GBM GRBCandidate

DiscretesDigital

Analogs

Science Data

• Power

– 28V regulated and unregulated

• MIL1553

– Commanding

• Science Interface (LVDS)

– Transport of science data to spacecraft solid-state recorder

• 1-PPS timing signal (LVDS)

– Timing pulse

• GBM GRB Candidate signal (LVDS)

– Notification of candidate Gamma-Ray Burst (GRB), from GBM routed through SC

• Discretes (LVDS)

– Pulsed and level digital signals from and to spacecraft

• Analog Monitoring

– Temperature and voltage monitoring by SC without having LAT powered

• Two power/signal sets: Prime and redundant

• All agreed to: Spectrum Astro SC-LAT Interface Document

LVDS: Low-Voltage-Differential-Swing signaling



Power Interface to SpacecraftPower Interface to Spacecraft

toUnregulatedVoltagePrimary

to

to

to

GRID or Anti-Freeze

Heaters,several

zones, eachzone has itsown set of

thermostats/heaters

VCHPsurvival/

operationalheaters

RegulatedVCHP Voltage

Primary

Turn on control fromSIU P and SIU R

RegulatedVCHP Voltage

Redundant

Prime

Prime

Redundant

RegulatedSIU-Prime

Voltage

SIUPrime

Regulated SIU-Redundant

Voltage

SIURedundant

Regulated MainDAQ Prime

Voltage

PDUPrime

Regulated MainDAQ Redundant

Voltage

PDURedundant

Spacecraft LAT

To other thermostats/heater zones

toUnregulatedVoltagePrimary

to

to

to

Redundant

To other thermostats/heater zones

Turn on control fromSIU P and SIU Rl

Cross-connected:either PDU

can useeither feed

All switches arecontrolled by

spacecraft

Power to restof LAT

To other switches(12 total)

To other switches(12 total)

• All power feeds from spacecraft can be turned off/on via ground

• Spacecraft turns off SIU/DAQ feeds when going to survival mode

• LAT start-up ICD: LAT-TD-01536

– Describes process of cold and warm boot (bring-up) of LAT



Spacecraft 1-PPS and GRB Candidate SignalSpacecraft 1-PPS and GRB Candidate Signal

S1S2

D

C

ENB

Multiplexer

1-PPS P

1-PPS RS1S2

D

C

ENB

Multiplexer

GASU DAQ BoardRedundant

GASU DAQ Board Prime

S1S2

D

C

ENB

MultiplexerFan-Out

E.g SIU P

Spacecraft LAT

To other crates

• 1-PPS signal from spacecraft prime and redundant are connected to both GASU DAQ boards (prime and redundant)

• GASU DAQ selects which SC signal to use

• Result is fanned out to all processor crates (SIU’s as well as EPU’s)

• Crate DAQ selects which GASU signal to use

• SC-LAT components are fully cross-connected

• Same for GBM GRB candidate signal



Spacecraft Discrete SignalSpacecraft Discrete Signal

Discretes P

Discretes R

SIU Crate Redundant

SIU Crate Prime

CPU

Spacecraft LAT

• Discrete Signals from SC to LAT:– Discrete LVDS-signals from spacecraft prime and redundant are connected to

both SIU crates (prime and redundant)– Reset discrete: P and R SC signal is logically Or’ed and used as CPU reset– Spare discretes: CPU selects whether to use P or R input and result is routed to

CPU discrete inputs (3 prime and 3 redundant)• Discrete Signals from LAT to SC (not shown)

– Discrete LVDS-signals from LAT SIU P and SIU R are driven to both, prime and redundant, spacecraft C&DH (Control & Data Handling) systems



LAT-SC Science InterfaceLAT-SC Science Interface

• GASU event builder

– Directs data from TEM’s to any of the CPU’s (not shown)

– Directs data from CPU to CPU

– Directs data from CPU to spacecraft

• Any CPU can direct data via either GASU DAQ (P or R) to SC

• Data is driven to both SC sections (P and R)

– SC needs to select which GASU to listen to

– GASU needs to know from which SC (P or R) the flow-control line is valid

– All configured via ground commanding

Receiver P

Receiver R

GASU DAQ BoardRedundant

GASU DAQ Board Prime

Switch

SIU P

Spacecraft LAT

S1S2

D

C

ENB

Multiplexer

S1S2

D

C

ENB

Multiplexer

To other LAT CPU’s

To other LAT CPU’s

EPU R

2 SIU’s,3 EPU’s



HarnessHarness

• Almost exclusively point-to-point cables (not harness)• Connectors are Micro-D and Sub-D• Cables are shielded-twisted pair, 24 AWG• Installation in layers; assembly drawings close to complete• Designed an fitted on 1:1 LAT model



Example: Connections LAT/Spacecraft and to Example: Connections LAT/Spacecraft and to LAT EMI ShieldLAT EMI Shield

+Y

Ra

dia

tor

Bra

cke

t-Y

Ra

dia

tor

Bra

cke

t

ACDElectronics

Box(x 24)

SIURdnt

SIUPrim

PDUBox

SC PRUPrim2.8A

regulated

+Y HeaterControl Box

JL-126

-Y HeaterControl Box

JL-139

SC PRURdnt2.8 A

regulated

JL-1

13

JL-1

12

JL-146

SC PDUPrim

unregulated

SC PDURdnt

unregulated

12 c + 6 gnd

12 c + 6 gnd

12 c + 6 gnd

12 c + 6 gnd

JL-1

07

JL-3

JL-4

JL-1

JL-2

4 pr tm +4 pr vm

JL-34

4 pr pwr +4 pr vm

4 pr pwr +4 pr vm

4 pr pwr

4 pr pwr

JL-141

6 -Y VCHP Heater Rdnt

6 -Y VCHP Heater Prim2 -Y Rad Antifreeze Heater Prim

2 -Y Grid Make Up Heater Rdnt

2 -Y Grid Make Up Heater Prim

2 -Y Rad Antifreeze Heater RdntJL-143

JL-147

JL-150

4 pr pwr

4 pr pwr

4 pr pwr

12 pr pwr

4 pr pwr

4 pr pwr

4 pr pwr12 pr pwr

48 pr tm

Grid (12 tm)Cal baseplate (16 tm)

JL-105 JL-37

JL-106

JL-149

2 pr pwr (AWG18)

2 pr pwr (AWG18)

2 pr pwr (AWG18)

JL-33JL-31

4 pr pwr

4 pr pwr

2 pr vm

2 pr tm

1 pr mil1553

1 pr mil1553

12 pr discrete

12 pr discrete

1 pr mil1553

1 pr mil1553

12 pr discrete

12 pr discrete

SCC&DHPrim

SCC&DHRdnt

SC AnalogMonitor Rdnt

SC AnalogMonitor Prim

4 pr pwr

4 pr pwr

12 pr pwr

12 pr pwr

XLAT plateJL

-12

3

JL-142

JL-140

JL-144

[ FROM ACD TO SC ]ACD Tiles (10 tm)ACD PMT Rail (8 tm)ACD Shell (10 tm)

2 pr pwr + 2 pr vm (-Y VCHP, sum of 6 Prim sw & sum of 6 Rdnt sw)

2 pr pwr + 2 pr vm (-Y VCHP, sum of 6 Prim sw & sum of 6 Rdnt sw)

2 pr pwr + 2 pr vm (+Y VCHP, sum of 6 Prim sw & sum of 6 Rdnt sw)

2 pr pwr + 2 pr vm (+Y VCHP, sum of 6 Prim sw & sum of 6 Rdnt sw)

4 pr tm

4 pr tm

32 pr tm

16 pr tm

16 pr tm

32 pr tm

16 pr tm

16 pr tm

2 pr pwr (AWG18)

-Y VCHP-XLHP Intf (4 tm)

Grid (12 tm)Cal baseplate (16 tm)

Timing Prim/Rdnt

GRBM Prim/Rdnt

JL-1

10

JL-1

09

GASUBox

JL-5

JL-7

JL-8

JL-4

4JL

-45

JL-4

1JL

-40 16 pr LATP +

8 pr pwr +2 pr tm + 2 pr vm

16 pr LATP +8 pr pwr +

2 pr tm + 2 pr vm

-Y VCHP Heaters (24 tm)-Y VCHP-XLHP Intf (12 tm)-Y VCHP-DSHP Intf (12 tm)

48 pr tm

SC PRUPrim25A

regulated

SC PRURdnt25A

regulated

16 pr pwr

16 pr pwr

4 pr tm + 4 pr vm

4 pr tm + 4 pr vm

(2 pr tm + 2 pr vm, pdu Prim & rdnt) + (2 pr tm + 2 pr vm, gasu Prim & rdnt)

(2 pr tm + 2 pr vm, pdu Prim & rdnt) + (2 pr tm + 2 pr vm, gasu Prim & rdnt)

16 pr pwr

4 pr tm +4 pr vm

16 pr pwr

4 pr vm

4 pr vm

28 pr tm

28 pr tm

JL-9,10,11

JL-13 … 28

JL-6

JL-1

08

8 pr tm

(8 c)*2 + 8 gnd

(8 c)*2 + 8 gnd

EPUBox(x 3)

TEMBox

(x 16)

JL-7

0,7

1,7

2

x 3

4 pr pwr + 2 pr tm + 2 pr vm

x 16

JL-8

9-1

04

4 pr pwr + 4 pr tm + 2 pr vm

JL-6

6,6

7,6

8

JL-46,47,48

JL-50 … 65

JL-7

3-8

8

x 3

x 16

100

51

JL-1

17

JL-230

JL-1

16

JL-1

19

JL-232

JL-1

22

JL-1

20

100

100

EPUBox

(test only)JL-1

55

JL-1

54

6 +Y VCHP Heater Rdnt

6 +Y VCHP Heater Prim

+Y Grid Rad Intf (4 tm)2 +Y Grid Make Up Heater (4 tm)+Y Radiator (8 tm)

[ FROM ACD TO PDU ]ACD BEA-Grid Intf (4 tm)ACD PMT Rail (8 tm)ACD Shell (4 tm)

Grid Rad Intf (8 tm)Radiator (20 tm)Radiator Antifreeze Heaters (8 tm)

JL-12

4 pr pwr +2 pr tm +2 pr vm

JL-49

100JL-29

JL-43JL-42

22 pr science +2 pr 1PPS +2 pr GRBM 22 pr science +

2 pr 1PPS +2 pr GRBM

JL-125



JL-1

24

11 pr science

11 pr science

11 pr science

11 pr science

NOTE: ONLY FIXED POSITION CONNECTORS ARESHOWN. CABLE CONNECTORS ARE NOT SHOWN.SC CONNECTORS NOT SHOWN. ACD NOT SHOWN.

JL-1

11

JL-1

14

JL-130

JL-131

JL-127

JL-129

JL-137JL-136

JL-134JL-133

2 +Y Rad Antifreeze Heater Prim

2 +Y Rad Antifreeze Heater Rdnt

2 +Y Grid Make Up Heater Prim

32 pr tm

JL-128

2 +Y Grid Make Up Heater Rdnt

AC

D T

em

pS

en

sor

Bra

cke

t

+Y VCHP Heaters (24 tm)+Y VCHP-XLHP Intf (12 tm)+Y VCHP-DSHP Intf (12 tm)

JL-69 JL-39 JL-35

16 pr tm

28 pr tm

JL-38

JL-32JL-30

JL-36

36 pr tm

-Y Grid Rad Intf (4 tm)2 -Y Grid Make Up Heater (4 tm)-Y Radiator (8 tm)

32 pr tm

14 prtm

14 prtm

JL-228

JL-1

21

JL-1

18

JL-234

JL-156 … 179

??

JL-180 … 203

x 24

GLAST LAT WIRINGDIAGRAM

REV 06

FEB 27, 2003 PY

JL-153

JL-2

04

… 2

27

8 pr tm + 40 pr vm

4 pr tm +20 pr vm

SPAREANALOGS

4 pr tm +20 pr vm

2 pr vm

2 pr vm 2 pr vm

2 pr vm

vm

vm

vm

vm

1 pr im

1 pr im

1 pr im

1 pr im

JL-1

15

2 pr tm

2 pr vm

JL-229JL-233

JL-235 JL-231

6 -Y VCHP Heater (12 tm)

6 +Y VCHP Heater (12 tm)+Y VCHP-XLHP Intf (4 tm)

JL-?

JL-151JL-148JL-145

JL-138JL-135JL-132

NOT USED CONNECTORNUMBERS

KEY:pr pairc controlgnd groundpwr powervm voltage monitorim current monitortm temp monitor

emi shieldspacecraftlocated +X sidelocated -X sidelocated +Y sidelocated -Y side

HDS high density D socketHDP high density D plugUDS micro D socketUDP micro D plugCIRC1S circular series I socketCIRC1P circular series I plugCIRC2S circular series II socketCIRC2P circular series II plug

JL-152

Reference TypeJL-1 55-CIRC1PJL-2 55-CIRC1PJL-3 55-CIRC1PJL-4 55-CIRC1PJL-5 26-HDPJL-6 26-HDPJL-7 78-HDSJL-8 78-HDSJL-9...12 26-HDSJL-13…28 26-HDSJL-29 37-UDSJL-30 100-UDSJL-31 100-UDSJL-32 100-UDSJL-33 100-UDSJL-34 100-UDSJL-35 37-CIRC2?JL-36 79-CIRC1SJL-37 100-CIRC1SJL-38 100-CIRC1SJL-39 26-HDSJL-40 78-HDPJL-41 78-HDPJL-42 62-HDSJL-43 62-HDSJL-44 100-UDSJL-45 100-UDSJL-46…49 100-UDSJL-50…65 51-UDPJL-66…68 100-UDPJL-69 100-UDSJL-70…72 26-HDPJL-73…88 51-UDPJL-89…104 26-HDPJL-105JL-106JL-107 26-HDSJL-108 26-HDSJL-109 100-UDSJL-110 100-UDSJL-111…114 26-HDPJL-115 13-CIRC1PJL-116 13-CIRC1PJL-117 66-CIRC1PJL-118 66-CIRC1PJL-119 13-CIRC1PJL-120 13-CIRC1PJL-121 66-CIRC1PJL-122 66-CIRC1PJL-123 22-CIRC1PJL-124 66-CIRC1SJL-125 66-CIRC1SJL-126JL-127JL-128JL-129JL-130JL-131JL-132 NOT USEDJL-133JL-134JL-135 NOT USEDJL-136JL-137JL-138 NOT USEDJL-139JL-140JL-141JL-142JL-143JL-144JL-145 NOT USEDJL-146JL-147JL-148 NOT USEDJL-149JL-150JL-151 NOT USEDJL-152 66-CIRC2?JL-153 51-UDPJL-154 26-HDPJL-155 100-UDPJL-156…179 100-UDPJL-180…203 79-CIRC2?JL-204…227 79-CIRC2?JL-228…235 MIL1553



Connections LAT/Spacecraft and to LAT EMI Connections LAT/Spacecraft and to LAT EMI Shield (focus)Shield (focus)



Verification & Test: Example TEM & FSWVerification & Test: Example TEM & FSW

• Processor: Motorola Power-PC• Flight Software• PMCIA LAT Communication Board for

– LAT Communication• Transition Board

– Trigger• TEM DAQ Assembly• TEM Power-Supply Assembly• 28-V Supply• LAT-TD-00861

Tower Power Supply Assembly

(1.5V/2.5V/3.3V/ 0-100V/0-150V)

TEM DAQ Assembly

LCB: LAT Communication Module

Transistion-card: Trigger Module

28-V Power Supply

Power-PC Processor

Flight Software



Verification & Test: RAD750/SIBVerification & Test: RAD750/SIB

• 3u-cPCI BAE RAD750 processor prototype

• 6u-cPCI Spacecraft Interface Board (Silver Engineering)

– MIL1553 interface

• Flight Software– Boot code development– SIB board code

driver/interface

Courtesy of Dan Wood, NRL

SIB

CPU



Verification & Test: Front-End Data SimulatorVerification & Test: Front-End Data Simulator

PC (one for 2 TEM’s)

CAL Front-End DataSimulator

PCI Bridge Card

High-SpeedSerial

Connection

PCI Bridge Card

0

7

PCI Bridge Card

PCI Bridge Card

TKR Front-End DataSimulator

PCI

PCI

TEM

Data into TEMlike CAL and

TKR sub-system

electronics

TCP-IP

Hard-Disk

One of 16Towers

• System uses 9 PC’s

– 8 PC’s for 16 TEM’s

– 1 PC for ACD

• Data transported to towers via high-speed data link; PCI bridge to local bus on simulator

• Data Simulators interface to TEM like CAL and TKR sub-system electronics

– CAL and TKR simulator board identical except code in FPGA’s

– Patch cable connect simulator to CAL and TKR TEM connectors

• Can operate TEM or LAT with data generated from simulations

• Data simulator board in layout



Verification & Test: TestbedVerification & Test: Testbed

spare

EPU-3

EPU-2EPU-1

spare spare

Pwr Dist. Box

GASU

spare

spare

ACD

SCsimulator

LAT EGSE

SIU P SIU R

TEM DAQ Modules TEM Power Supplies

TKR and CAL Electronics Simulators

12 ACD Electronics Cards

• Full DAQ set with EM2 hardware (each with identical interfaces and functionality as flight)

• Incremental built according to plan (complete testbed Feb04)

• All DAQ modules including 16 TEM’s

• Harness like flight

• TKR and CAL front-end electronics for 1 tower, front-end simulator boards for other 15 towers

• Full set of ACD EM2 electronics

• Spectrum Astro SC simulator

• Excellent hardware and software testbed

Spectrum Astro Simulator



Verification & Test: Spacecraft InterfaceVerification & Test: Spacecraft Interface

Power

SIIS

MIL1553

LAT

1 PPS

GBM GRBCandidate

DiscretesDigital

Analogs

Science Data

• Use Spectro-Astro provided Spacecraft Instrument Interface Simulator (SIIS)

• Power – Manual off-on switch

• Control & Data Handling (C&DH)– MIL1553– Science Interface (LVDS)– 1-PPS timing signal (LVDS)– GBM GRB Candidate signal (LVDS)– Discretes (CMOS)– Analog Monitoring

• Present plan is for SIIS to only provide– Primary interface

• can’t test prim-redundant interface response

– Timing accuracy of 1 PPS interface not sufficient to test timing interface performance

• Work in progress

LVDS: Low-Voltage-Differential-Swing signaling



SummarySummary

• Flight designs for electronics components well advanced• Engineering models in use in EGSE test-stands• Flight-designs of DAQ ASIC’s submitted to fabrication • Component verification and test plans described• To be worked on:

– Worst-case & timing analysis plus test-procedures for several modules still need to be completed

– EM2 tests (multi-tower with GASU) scheduled to be started end of April 03

– Documents still need to be completed• The electronics is ready to purchase flight

components/hardware



BackupBackup



Trigger PathTrigger Path

• TKR, CAL, and ACD produce fast (< 700 ns) trigger input signals from their front-end comparators

– CAL, LO and HI discriminator signals• LO is used as monitor trigger for TKR• HI is used for very high energy (>10GeV)

events– TKR, Layer OR– ACD, LO and HI discriminator signals

• LO is efficient for minimum ionizing particles

• HI selects CNO events • TEM produces sub-system specific trigger

primitives for CAL & TKR (e.g. 3-in-a-row)• Global Trigger in GASU receives trigger inputs

from ACD and TEM’s and decides whether to trigger the instrument

• If instrument is triggered, Trigger Accept signal is distributed back to front-ends -> Event data is generated

• Total time from particle in detector to receipt of trigger accept signal: < 2 usec

GASU

( includes Global Trigger)

Trigger Inputs

TEM

Trigger Accept

TKR CAL

ACD

16 Towers



Event Data PathEvent Data Path

• Event data from CAL & TKR are acquired by TEM’s, reformatted, buffered, and transmitted via GASU to all Processor Units (for ACD the TEM function is included in the GASU)

• EPU’s assemble LAT events and filter the data to reduce the event rate of ~6 KHz down to ~30 Hz

• Events arriving at EPU’s have target EPU ID in header, so each EPU only processes sub-set of events and forwards filtered events via GASU to other processors or spacecraft solid-state recorder

• All pipe-line stages subject to flow-control

• Dead-time is monitored on an event-by-event basis

GASU

Event Data

EPU/SIUTEM

Data to Spacecraft

TKR CAL

ACD

Towers



Assemble TEM Event

Datapath & Building EventsDatapath & Building Events

Front-End TEM

CAL-TRG FIFO

CAL ADC Data

With 3 Events

Digitize on

trigger

TKR FIFOWith 1 Event

~50,000 TKR GTFE MEM Cells

With 2 Events

Latch on

trigger

FIFO for each Tower

Event Builder

Cable

Event Processing Unit (EPU)

Trigger Data

Accept/Reject

From other TEM’s

Assemble LAT Event

Processor

SW Filter

Tower

Spacecraft