LAXPC

UVIT

SSM

CZT

SXT

ASTROSAT

Dhiraj Dedhia - LAXPC Team

January 27, 2014 2

LAXPC on ASTROSAT

Three Independent and modular electronic systems for 3 LAXPC Detectors to meet the redundancy strategy.

All three electronic systems to use a common and accurate time reference.

Payload health monitoring & Command control for operational flexibility.

Independent electrical interfaces to satellite buses (Power, Tele-Command & Telemetry) for all the sub-systems.

LAXPC CDR

January 27, 2014 3

LAXPC Ground Checkout System

Ground Checkout System is a Compact Real Time I/O (NI Hardware) and LabVIEW based data acquisition to simulate BDH & BMU satellite sub-systems:

B.M.U Simulation – TM / TC

Select the command from Command list, convert to BMU specified format and transmit to payload

Simulate BMU and receive TM data and display in original form.

B.D.H / S.S.R. Simulation – HBT Acquisition

CRIO receives data in serial form @3MHz, in packets of 2K bytes.

Data Analysis

Display the counts information, PHA and the house keeping information.

Display the plot of the light curve and pulse height spectrum plot.

Data Archival

Store the data received in Hard Drives, over Ethernet.

MCA (AMPTEK-8000A) to acquire a spectrum from CSPA output of each Anode.

LAXPC CDR

January 27, 2014 4

Processing Electronic (PE)

Processing Electronic (PE)

LAXPC CDR

January 27, 2014 5

PE PDR to CDR Changes

1. Change of DC-DC: IR DC-DC in place of MDI DC-DC as per advisory.2. Series Resistor for CWR06 Capacitors: As per Advisory added a series res to avoid inrush

current problem.3. Dropped two modes of PE:

a. Spectral Mode: Dropped this mode, since only single event spectrum does not help much since 85% of events above 34keV in Xenon will be double events. And these spectrums data will be received along with HBT data hence no use as quick look data. Same can be generated more efficiently from raw time tag event data on ground.

b. No-PHA mode: Earlier this mode was planned to same time in converting the PHA information and storing of 3 extra bytes as compare to event mode 5-byte data. Now the currently the CSPA output pulse recovery time is about 50 to 70µs. Hence, dead time of EPL is about 52 to 57µs for genuine event while about 30µs in case of non-genuine event. Thus PE (including DELI dead time) can handle about 13,000 random events per sec. there is a Fast counter mode to handle the high count rates.

4. We had faced the data missing problem at higher temperature and then even up to 30°C. We had discussed the issue of sync loss due to data byte missing with ISAC experts and even with team of senior engineers of TIFR. It was concluded that due to high density of layout and 10-layer board of DELI card stray capacitor effect at 24MHZ operation of microcontroller its missing the data bytes. Finally we have change the crystal to 16MHz and now even at entire temperature range we have not seen the sync loss. (PE/DELI note to project & PE email by Prof. Manchanda dt 20/9/12). (Corrective action note by Pankaj on 06/08/13).

LAXPC CDR

January 27, 2014 6

PE Code-walk Review

The LAXPC’s all onboard software/codes were reviewed by code-walk review committee at TIFR.

The committee had extensive and in depth review sessions during October 3-5, 2011 with the LAXPC team

members. The queries, critical comments and suggestions that came up during the review process, which

were given to LAXPC team. To this, an action taken report was filed by the LAXPC team.

Meanwhile extensive testing and qualification of the Processing Electronics (PE) package of LAXPC has

revealed some performance problems. So, the LAXPC team requested the Code-walk committee to hold up

the close-out till the time the above issues were sorted out. Consulting various hardware experts, the

LAXPC team has implemented a solution - reducing the operational frequency of DELI from 24MHz to

16MHz. The team has extensively tested the hardware and found that the hardware is now functioning well.

Subsequently the LAXPC team has requested for a final close-out meeting of the code-walk, which took

place on November 4, 2013. The code-walk committee has insured the implementation of the changes and

thus approved and cleared the LAXPC software design.

LAXPC CDR

January 27, 2014 7

PE EMI-EMC Test

LAXPC CDR

January 27, 2014 8

PE EMI-EMC Test

The PE incorporates two DC/DC Converters i.e. AMF2805S converter and

AMF2812D converter with common input filter AMH461. The system having

100kHz ,500kHz and 10MHz known frequencies available.

Following tests were carried out on PE :

Conducted Emissions on Primary Power lead (CE03 -15 kHz to 50 MHz),

Conducted Susceptibility Tests on Primary Power lead,

Sine Susceptibility (CS01, CS02 - 30 Hz to 50 MHz),

Spike Susceptibility (CS06 – limited to 10V peak as per QA request),

Radiated Emission Test (RE02 Electric Field - 14 kHz to 18 GHz),

Radiated Susceptibility Test (RS03 Electric Field - 20 MHz to 18 GHz),

Radiated Susceptibility Test on spot frequencies ( 2.245GHz,8.125GHz and 8.3GHz).

LAXPC CDR

January 27, 2014 9

PE EMI-EMC Test

Conducted Emissions(15KHz-50MHz) Live Line, System E60

LAXPC CDR

January 27, 2014 10

PE EMI-EMC Test

Conducted Emissions(15KHz-50MHz) Return Line ,System E60

LAXPC CDR

January 27, 2014 11

PE EMI-EMC Test

Radiated Emissions Ambient Profile (14kHz-30MHz)

LAXPC CDR

January 27, 2014 12

PE EMI-EMC Test

Radiated Emissions Ambient Profile (30MHz-300MHz),H-POL

LAXPC CDR

January 27, 2014 13

PE EMI-EMC Test

Radiated Emissions Profile (30MHz-300MHz),H-POL

LAXPC CDR

January 27, 2014 14

PE EMI-EMC Test

Radiated Emissions Ambiant Profile (30MHz-300MHz),V-POL

LAXPC CDR

January 27, 2014 15

PE EMI-EMC Test

Radiated Emissions Profile (30MHz-300MHz),V-POL

LAXPC CDR

January 27, 2014 16

PE EMI-EMC Test

Radiated Emissions Ambient Profile (300MHz-1000MHz),H-POL

LAXPC CDR

January 27, 2014 17

PE EMI-EMC Test

Radiated Emissions Ambiant Profile (300MHz-1000MHz),V-POL

LAXPC CDR

January 27, 2014 18

PE EMI-EMC Test

Radiated Emissions Profile (300MHz-1000MHz),V-POL

LAXPC CDR

January 27, 2014 19

PE EMI-EMC Test

Radiated Emissions Profile (1GHz-18GHz),H-POL

LAXPC CDR

January 27, 2014 20

PE EMI-EMC Test

Radiated Emissions Profile (1GHz-18GHz),V-POL

LAXPC CDR

January 27, 2014 21

PE EMI-EMC Test

• Conducted emissions exceeding the limit line at certain frequencies. The

maximum emission level is 12.9dB at 20.99MHz in the return line.

• Radiated Emissions were exceeding the limit line at certain frequencies

between 500kHz-410MHz. The maximum emission level is 26dB higher

than the allowable limit at 17MHz.

• During Conducted Susceptibility tests CS01 and CS02 tests some

anomalies found i.e. some frames were missed.

• During Conducted Susceptibility CS06 test the performance of the

subsystem was normal.

• During Radiated Susceptibility test the performance of the subsystem

was normal. (Pg.57)

LAXPC CDR

January 27, 2014 22

PE Vibration Test

LAXPC CDR

Frequency (Hz)Amplitude

Qualification level Acceptance level5 – 20 12.4 mm 8.3 mm20 – 50 20 g 13.3 g50 - 70 15 g 10 g70 –100 8 g 5.3 g

Sweep rate 2 oct. / min. 4 oct. / min.

Frequency (Hz)Amplitude

Qualification level Acceptance level5 – 20 9.3 mm 6.2 mm20 – 70 15 g 10 g70 –100 8 g 5.3 g

Sweep rate 2 oct. / min. 4 oct. / min.

PE Package, Deck mounted

Sine Vibration Test specifications

Parallel to the mounting plane

Normal to the mounting plane

January 27, 2014 23

PE Vibration Test

LAXPC CDR

Frequency (Hz)PSD (g2 / Hz)

Qualification level Acceptance level20 – 100 + 3 dB / oct. + 3 dB / oct.100 – 700 0.15 0.07

700 – 2000 - 6 dB / oct. - 6 dB / oct.

Overall gRMS 12.8 g 8.5 g

Frequency (Hz)PSD (g2 / Hz)

Qualification level Acceptance level20 – 100 + 3 dB / oct. + 3 dB / oct.100 – 700 0.1 0.04

700 – 2000 - 3 dB / oct. - 3 dB / oct.

Overall gRMS 11.8 g 7.9 g

Random Vibration Specifications:

Parallel to mounting plane

Normal to mounting plane

January 27, 2014 24

PE Vibration Test

• PE – 60 (FSM) was successfully vibrated at Acceptance Level.

• We have done the pre and post vibration tests during each axis vibration by giving

the simulated pulses to input of PE and checked the performance.

• After vibration of PE and STBG (FSM) at proto flight level, they underwent the TVAC at TIFR. During

TVAC we had seen the PCB failure in Power card of STBG. On further diagnosis it was observed that 2

cards of STBG and 3 cards of PE have inner layer with 35µ Cu thickness.

• New PCBs were made with ISAC help with Cu layer thickness of 70µ and cards were populated at CEFS.

Old cards were replaced with new cards. The FSM models of both STBG and PE underwent re-

vibration at acceptance level test (to retain the flight worthiness).

• Finally, after the discussion with QA team it was concluded that since there was no failure in PE (FSM)

during (1st) proto flight level vibration and post vibration TVAC, this vibration test will be treated as

complete. Hence all other three PE packages can be vibrated at acceptance level.

• STBG (FSM) and PE (FSM) packages have been subjected to qualification level TVAC tests successfully.

LAXPC CDR

January 27, 2014 25

PE Thermal Cycles

LAXPC CDR

PE underwent Qualification Level Thermal cycle

PACKAGEOperating

emperature (C)

Qualification (C)

Acceptance (C)

Processing Electronic (PE) 0 to 40 -15 to 55 -10 to 50

LAXPC has all Flight worthy packages (No QM / EM )

January 27, 2014 26

PE Thermovac Test

LAXPC CDR

Power Supply

Ground Check System

AS-LX-EL-60

(PE FS)

AS-LX-EL-70

(STBG -FS)

Signal Generator

Outside 1.2m TVAC, ISAC Inside 1.2m TVAC, ISAC

January 27, 2014 27

PE Thermovac Test

LAXPC CDR

All parameters were within acceptable range & functionality of the package found OK.

TVAC test completed successfully.

2.5V 3.3V 5V 12V2.535-2.542

4.239-4.243

4.906-4.911

4.492-4.514

2.539-2.540

4.209-4.211

4.888-4.890

4.511-4.533

2.539 4.223 4.896 4.516

±0.1V ±0.1V ±0.1V ±0.1V

Long Cold Test at -15°

Long Hot test at 55°

Ambient

Acceptable Tolerance

Monitor Voltages during TVAC

@36V PowerLong Cold Test at -15°

334mA 12.03W

Long Hot test at 55°

315mA 11.34W

Ambient 325mA 11.70W

Acceptable Tolerance

±5% ±5%

PE Current measured during TVAC

January 27, 2014 28

BBC Data Light Curve Through PE

(during TVAC)

LAXPC CDR

January 27, 2014 29

Event Data Through PE

(during TVAC)

LAXPC CDR

January 27, 2014 30

LBT Data Through PE

(during TVAC)

LAXPC CDR

January 27, 2014 31

Detector Signal Through PE (post-TVAC test)

LAXPC CDR

January 27, 2014 32

Thank You

LAXPC CDR