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KAKL edited this page Feb 27, 2019 · 67 revisions

SPACEDOS

Physical dimensions

Physical dimensions

Large view

Energetic range and Climatic endurance

Dissipated Energy range: from 200 keV to 9 MeV

Energy Resolution: < 50 keV

Temperature Stability: from -50 ℃ to +50 ℃ within error +50 keV

Used Sensor: HAMAMATSU S11773-02 (PIN diode 5 x 5 x 0.5 mm3)

Electrical interface

Signal Description
PC7 Universal IO pin
PC3 Universal IO pin
RX0 RS232 Receive (3.3 V)
TX0 RS232 Transmit (3.3 V)
RST# Reset (trough capacitor)
GND Ground
3V3 Power supply +3.3 V
5V Internally connected to +3.3 V

Power consumption: 2.6 mA from 3.3 V

Communication protocol

Sample of output data

#Cvak...
#Hmmm...
$DPSD,00000f08,7fc5,002f,0000,0000,0001,0000,0000,0000,0000,0100
$HKSD,244,3848,32778,254,0,0,32709,47,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
$BESD,0004,0000010e,00000000,00000000,00000001,00000000,00000000,00000000,00000000
$ADSD,000000de,00000003,00000000,0000011d,00000000,00000000

SPACEDOS sends $DPSD, $HKSD and $BESD messages each cca 15 seconds. $ADSD message is sended ones per one day.

Communication speed is 2400 baud.

Power On

#Cvak…

This information just says hello after power on.

Initiation complete

#Hmmm...

Initiation of the SPACEDOS HW is done. Initiation is completed up to one second after power on.

DPSD - SpaceDos Data Payload message

$DPSD, <uptime>, <noise channel>, <0.1 MeV>, <0.14 MeV>, <0.21 MeV>, <0.33 MeV>, <0.66 MeV>, <1.68 MeV>, <4.72 MeV>, <'>=9 MeV'>, <DC offset>

Value Length Type Note
$DPSD 5 B Char Header
uptime 4 B Hex Time from power on
noise channel 2 B Hex this channel containing noise
0.1 MeV 2 B Hex number of particles with absorbed energy above 0.1 MeV
... ... ...
'>=9' MeV 2 B Hex Overrange particles
DC offset 2 B Hex Offset of ADC

This messages should be stored for long period and transmited to the ground as a batch.

Minimal data payload (without timemark) is 18 B per 15 s => 103680 B per day

HKSD - SpaceDos HouseKeeping message

$HKSD, <measurement No.> , <uptime>, <filter suppressions>, <position of the 1-st channel>, <1-st ch.>, <2-nd ch.>, <3-rd ch.>,...

There is a packet with housekeeping information. Transmission of this packet is done besides other experiments hosekeeping data. Total length of this packet should be shorten.

Value Range type Note
$HKSD fix Char Header
measurement No. 0..65535 Dec
uptime 0..4294967295 Dec
filter suppressions 0..65535 Dec Number of ussage of digital filter for double peak suppression
position of the 1-st channel 0..511 Dec
1-st ch. 0..65535 Dec Number of events in 1-st ch.
2-nd ch. 0..65535 Dec Number of events in 2-nd ch.
... ...
50-th ch. 0..65535 Dec Number of events in 50-th ch.

BESD - SpaceDos BEacon message

$BESD,<counter>, <0.1 MeV>, <0.14 MeV>, <0.21 MeV>, <0.33 MeV>, <0.66 MeV>, <1.68 MeV>, <4.72 MeV>, <'>=9 MeV'>

This message contains cumulative data for beacon transmission.

Value Length Type Note
$BESD 5 B Char Header
counter 2 B Hex Number of the beacon message
0.1 MeV 2 B Hex number of particles with absorbed energy above 0.1 MeV
0.14 MeV 2 B Hex number of particles with absorbed energy above 0.14 MeV
... ... ...
'>=9' MeV 2 B Hex Overrange particles

ADSD - SpaceDos Almanac Data message

$ADSD, <0.1 MeV 1 day old>, <0.14 MeV one day old>, <0.66 MeV one day old>, <0.1 MeV two days old>, <0.14 MeV two days old>, <0.66 MeV two days old>

This message contains two days old data for the beacon transmission purposes.

Value Length Type Note
$ADSD 5 B Char Header
0.1 MeV one day old 4 B Hex number of particles with absorbed energy above 0.1 MeV one day before
0.14 MeV one day old 4 B Hex number of particles with absorbed energy above 0.14 MeV one day before
0.66 MeV one day old 4 B Hex number of particles with absorbed energy above 0.66 MeV one day before
0.1 MeV two days old 4 B Hex number of particles with absorbed energy above 0.1 MeV two days before
0.14 MeV two days old 4 B Hex number of particles with absorbed energy above 0.14 MeV two days before
0.66 MeV two days old 4 B Hex number of particles with absorbed energy above 0.66 MeV two days before
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