EIS/Solar-B: 3. Electrical Interface to MDP

EIS MDPPIM

HK PIM

DHU

DR

analog data (temperature, current, etc.) S/C bus

image compression

status data

commandEIS table writesoftware patch

science data

table dump

3-1 Functional Block Diagram

information of timeMDP buffer status power control

・ occurrence of flare・ flare position

XRT

power distributor28 V TCI-B

COM

uplinkdownlink

PIM

EIS/Solar-B: 3-2 Interface lines

differential RS-422 line interface

HS-26C31 HS-26C32

DATACLOCKGATE

MDP BUFFER STATUS

COMMANDCLOCKENABLE

MDPEIS

low-powerRS-42264 kHz

NormalRS-4221 MHz

Power control interface ?

‘MDP Buffer Status line is used 1: for safe exchange of ‘input buffer’ in MDP. 2: when post compression buffers become almost full.

All electrical interface lines betweenEIS and MDP are digital interface lines.

EIS/Solar-B: 3-3 Flow of image data processing in MDP

Input Buffer

SOT-A

SOT-B

XRT-A

XRT-B

EIS-A8Mbyes

EIS-B8Mbyes

bitcomp.

buffer A

buffer B

image compression

SOT-A

SOT-B

XRT-A

XRT-B

EIS-A8Mbytes

EIS-B8Mbytes

Post Compression Buffer

output buffer

DHU

EIS can use functions of bit compression & image compression in MDP.

DPCM

JPEG

EIS/Solar-B: 3-4 Data Lines

・ Data line: normal differential RS-422 line, 1Mbps ・ Science data (spectrum or image) ・ Status data ( ~1 sec interval; Report of shutter & scan mirror motions will be required.) ・ Dump data of EIS observation table ・ Dump data of EIS compression table MDP knows kind of data by looking at the header part after the data are transferred. 12 bits data flow in this data line. maximum transfer speed: 1 Mbps (TBD)・ EIS Input Buffer in MDP: 1. double buffer system 2. buffer size: 8 Mbytes/buffer

EIS MDP

・ Concept of Data Format: fixed-length header + variable-length data maximum image size in a single packet = 256 kpixel science data: header + 12 bits CCD image data The number of pixels in the image data is a multiple of 8. Is this OK ? other data : header + 12 bit data (Upper 4 bits are all 0. Is this OK ?)

EIS can send data to MDP at any time when a status of MDP buffer status line is READY.

EIS/Solar-B: 3-5 Data Compression

CCD buffer DHU

DR 2.4 Gbits

14 bit →12 bit bit compression

inputbuffer

EIS MDPbit comp.

image comp.

post comp. buffer

2 Mbps (TBD) line for SOT, XRT & EIS1 Mbps line 12 bits data

for EIS

JPEG

EIS can use 2 Mbps line nominally for 0.5 s every 6 seconds.

max. 167 kbps, but DR for EIS will become full in a short time.

DPCM

(selectable) (selectable)

header

Capacity of DR will be ~3 Gbits, but only downlink 2.4 Gbits during the KSC/DSN contacts.

Header includes information ofdata compression in MDP.

EIS/Solar-B: 3-6 Command Lines

MDP contractors would like to know: 1. list of commands required for EIS operation 2. how ICU reads commands from MDP (Please explain it.) 3. response time for a command 4. size of buffer ? 5. whether there is some restriction for the data format or not.

Command line: low-power differential RS-422 line, 64 kbps

Command answer back: receipt of command put the command data into status data for confirmation

EIS/Solar-B: 3-7 Counter-plan for Errors

・ When some error happens in EIS-CPU due to SEU,

does EIS side request anything to MDP ? or does EIS side deal with the error by itself ?

・ When some error happens in MDP due to SEU,

does EIS side request anything to MDP backup system for safety ? or does EIS side deal with the error by itself ?

EIS/Solar-B: 3-8 Management Plan of Time

EIS MDP DHU

clock generator

clock line incommand line

clock counter

PIM

5 4 3 2 1

clock counter・ obtaining count c1 at a start of exposure・ obtaining count c2 at a start of data transfer.

1: header2: count c1 at start of exposure3: count c2 at start of data transfer4: image parameter5:image data

・ obtaining c3 at start of data receipt・ obtaining c4 at start of receiving PIM time.

PIMtime

These counts are added to compressed image data.

These counts are added to image data.

A: CCSDS packet headerB: count c3 at start of receiving image dataC: PIM timeD: count c4 at start of receiving PIM timeE: compressed image data

E 4 D C B 3 2 1 A

data line for image data

In case of data except for science data, EIS only put counter value at start of data transfer.

EIS/Solar-B: Appendix. Radiation Environment of MDP

Solar-B: launch window: 2004 orbit: sun-synchronous orbit operation period: 5 years altitude: 600 km, inclination: 97.79 deg

Results of total-dose evaluation in case of Solar-B orbit by MHI 3 mm thickness Al shield is assumed.

a) trapped proton: 1.37×102 rad/year b) trapped electron: 9.35×102 rad/year c) galactic cosmic ray: 3.52×102 rad/year d) flare - normal: 7.27×102 rad/year e) 90% worst : 4.39×103 rad/year

Total dose for 5 years: (a + b + c + d) ×5 years = 9.01×103 rad (a + b + c + e) ×5 years = 2.73×104 rad

EIS/Solar-B: Flare Detection

The following is a baseline of flare detection.

・ Detection of flares is done by XRT.・ 8×8 on-chip summation image covering the whole XRT field of view will be used for flare patrol.・ The flare patrol image will be taken every ～ 30 sec (TBD).・ Information on flare detection is sent to EIS by MDP. 1. Flare detection 2. Flare location in XRT CCD coordinate; X=0-255, Y=0-255 (TBD)・ Duration of flare mode TBD

timeflarepatrolimage

～ 30 s

time for XRTdata analysis (TBD)

Flare!

flare mode

flare observationwith EIS

time for change of EIS FOV