CORONASF telemetry system

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CORONAS-F telemetry system
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Introduction

• Brief description of telemetry system of orbital
  solar observatory CORONAS-F
• Reported by Lisin Dmitry, head of department of
  on-board telemetry systems, Institute of
  Terrestrial Magnetism, Ionosphere and
  
  Radiowave Propagation, Russian Academy of
  Sciences, Troitsk
• http//www.izmiran.rssi.ru/
• E-mail lisin_at_izmiran.rssi.ru

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Report content

• Structure of CORONAS-F telemetry system
• General parameters of SSNI (SDAS)
• Block diagram of SSNI
• Exchange protocols
• Possibilities of real-time control of scientific
  instruments
• Data amount calculations

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Structure of CORONAS-F telemetry system
Control Station
Commutation Unit
Central Commutation Unit
Simply commands
Simple telemetry
Power
Instruments
Precision time
Data
Control
Day
Night
Cold reserve unit
IZMIRAN Telemetry Center
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General parameters of SSNI

• Board time absolute accuracy 1 millisecond
• Acquisition rate of each instrument
  from 1.9 to 15 Kbytes/sec (on demand)
• All instruments have individual connection lines
  with SSNI (no shared buses)
• On-board RAM 128 Mbytes
• Primary downlink speed 1 Mbit/sec
• Uplink speed 4800 bit/sec
• Downlink via TR137 (worst case) 64 Kbit/sec

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Block diagram of SSNI
External devices
Unit A (primary)
Unit B (in cold reserve)
Input/Output buffers
32-bit board timer
biphase modulator
Actel FPGA
FRAM module 16 Kb
ROM module 16 Kb
2 simple commands from RTS
Power
Bistable relay
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Exchange protocols
30 us
960 cycles
Sync 32768 Hz
Any time
Any time
Ready Flag
Read data
Permission to send
Set data
Data
1
1
0
0
0
(Single or 8 bit bus)
...
Total 960 bit 120 bytes per frame
SSNI reads one frame 16 times per second
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Possibilities of real-time control of scientific
instruments
CORONAS-F
512Kbit/sec selected line connection
Instrument data users
Downlink 1 Mbit/sec
Internet
ftp, telnet, http, e-mail
Uplink 4800 bit/s
Session time approx.10 min
IZMIRAN Space Information Technologies Center
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Data amount calculations

• Data amount per 1 session 1 Mbit/s 10 min
  128 Kbytes 600 sec 75 Mbytes
• Command information amount 100-200 Kb per
  session
• Time between sessions 12 hrs (at one point)
• Possible downlink sessions per day 4 (Russia
  Germany)
• Maximum data amount from scientific instruments
  475 300 Mbytes daily
• Current RESIK memory quota 16 16 32 Mbytes