Experiment Interface Types. RS422 - LP, LP, DP, DP, baud rate 38,4k. RS422 - CORES, baud rate 115,2k. RS422 - RFA, baud rate 19,2k. RS232 â ...
János Nagy, Kálmán Balajthy, Sándor Szalai, István Horváth Hungarian Academy of Sciences, Wigner Research Center for Physics, (former name KFKI-RMKI), Budapest, Hungary
International Space Station Research Investigations and Experiments IKI RAS, Moscow, Russia, April 9-11, 2015
Block Diagram of Obstanovka
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Advantages of Multiprocessor Arrangement experiments are located on two space branches both are galvanic isolated, and supplied by power from different feeders individual DACU units in every branch suppress coupled noise, EMC interactions and avoids creating ground loops Reserve computing capacity by distributing tasks between two parts
Location of DACU Units in ISS
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Experiment Interface Types RS422 - LP, LP, DP, DP, baud rate 38,4k RS422 - CORES, baud rate 115,2k RS422 - RFA, baud rate 19,2k RS232 – DFM2 SAS3 10 Mbit/s Ethernet Analogue Inputs DFM1, CWZ, CWZ +-2V Normal and Burst mode
Three Onboard Computers of Obstanovka
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The opened BSTM, PC/104 cards and heatsink is visible
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BSTM Interface Types Ethernet 10 or 100 Mbit/s - ISS Onboard Ethernet 10 Mbit/s, optically isolated –Amateur
Radio Special Onboard Interface, optically isolated – BITS Special Onboard Interface, optically isolated – Slow Telemetry DACU1, DACU2, SAS3 - Ethernet 10 Mbit/s, optically isolated
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PC/104 cards Processor card DC-DC Power Supply unit Serial interface card Ethernet switch and HUB power switch cards BITS interface card Slow Telemetry Interface Analog-to-digital converter EGSE cards Simple signal conditioners, in DACU
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Critical Technological Points Power consumption BSTM 30 Watt, DACU 12 Watt Weight, mass BSTM 4.7kg, DACU 3.1kg Thermo vacuum test Vibration test EMC Data Transmission through Ethernet between BSTM and DACU units HDD power and vibration test
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Input current at Power On
Test Facilities, Vacuum Test and Vibration Test
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First Heatsink
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First Heatsink
Redesigned Heatsink
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2.5” Removable HDD RACK
Ethernet Test UTP - Unshielded Twisted Pair - cable of cat 5 was
applied in transmission tests. The nine-meter long cable contained two pairs of PC-50 and six pairs of PC-19 type connectors. The distance between the neighboring connectors measured 1 m.
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Major Results of Testing Ethernet Line for ISS 100 MHz transmission speed could be achieved.
There was no loss in data packets during long time test without external noise. External noise sensitivity is high, especially at connectors. Waveform distortion reached 5-7%, and it was 15% if external noise was applied. The application of S-STP – shielded twisted pair – with galvanic connected connectors is suggested
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Arrangement of Ethernet Test
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BSTM functions Long term storage of enormous data amount Transfer of some data to Earth through different
radio channels Control of the experiments: radio + scenario Powering the experiments
Commanding the experiments (mode and parameter
setting)
Data Quotas Daily Quota = storage capacity / 180 day / 11
experiments. Same for each experiment. Restquota = unused quota of previous day. Redistributed in portion of used space of previous day. A very simple example with 2 experiments: 1. Day: used 40/100 and 100/100 units, remained 60 2. Day: used 40/117 and 143/143, remained 77 3. Day: used 40/116 and 161/161, remained 76
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Stored data format One new file in each hour Each record contains: Identification: the experiment number Time stamp of origin, when the data block was
created (by the DACU / SAS3 / BSTM) Indicators and control information for example: block length, Housekeeping / science data indicator
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Communication channels IUS On Board Ethernet of RS-ISS Accepts commands from Earth, and sends acknowledgement of them Sends housekeeping data to Earth Generates time stamps BITS Bit Serial Interface Slow telemetry AMR Amateur Radio Channel
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Properties of channels Radio visibility: 3 times 5 minutes / day Slow bode rate, only some housekeeping data can be
transferred AMR can be used from different points of the Earth, But AMR is dedicated for educational purposes
Telecommand Generated in EGSE Processed in Command
Center IUS receives radio command, forwards it through BSTM - DACU to experiment BSTM sends acknowledgement Execution at once
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Scenario Generated in EGSE Copy on new data storage disc Astronaut changes the disc in the BSTM A scenario contains: Powering commands for DACU Mode commands and parameters for the experiments Delays
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Astronaut operations Mounting and caballing the devices Powering BSTM, DACUs BSTM indicates connected DACUs Indicators for disk change Switch BSTM power off Change the data storage pack Switch BSTM power on
Installation of Obstanovka in the space in April 2013
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Obtanovka team in Budapest
Thank you for your attention!
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