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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2019 Athanasios Theocharis <athatheoc@gmail.com>
# This was made under ESA Summer of Code in Space 2019
# by Athanasios Theocharis, mentored by Daniel Estevez
#
# This file is part of gr-satellites
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
'''
Construct for the CCSDS Space Packet ( CCSDS 133.0-B-1 )
The User, in case of utilizing the secondary header, should be careful and define the sizes of the payload.
After choosing which time format will be used, the User should check the sizes of the secondary header construct,
as well as the payload variable size of the FullPacket[TimeCodeFormat].
'''
from construct import *
PrimaryHeader = BitStruct('ccsds_version' / BitsInteger(3),
'packet_type' / BitsInteger(1),
'secondary_header_flag' / Flag,
'AP_ID' / BitsInteger(11),
'sequence_flags' / BitsInteger(2),
'packet_sequence_count_or_name' / BitsInteger(14),
'data_length' / BitsInteger(16))
#########################################
## CUC related structs
#########################################
PFieldCUC = BitStruct('pfield_extension' / Flag,
'time_code_identification' / BitsInteger(3),
'number_of_basic_time_unit_octets' / BitsInteger(2),
'number_of_fractional_time_unit_octets' / BitsInteger(2))
PFieldCUCExtension = BitStruct('pfieldextension' / Flag,
'number_of_additional_basic_time_unit_octets' / BitsInteger(2),
'number_of_additional_fractional_time_unit_octets' / BitsInteger(3),
'reserved_for_mission_definition' / BitsInteger(2))
TimeCodeCUCWithPField = Struct('pfield' / PFieldCUC,
'pfield_extended' / If(this.pfield.pfield_extension == 1, PFieldCUCExtension),
'basic_time_unit' / IfThenElse(this.pfield.pfield_extension == 0,
BytesInteger(
this.pfield.number_of_basic_time_unit_octets + 1),
BytesInteger(
this.pfield.number_of_basic_time_unit_octets + 1 +
this.pfield_extended.number_of_additional_basic_time_unit_octets)),
'fractional_time_unit' / IfThenElse(this.pfield.pfield_extension == 0,
BytesInteger(
this.pfield.number_of_fractional_time_unit_octets),
BytesInteger(
this.pfield.number_of_fractional_time_unit_octets +
this.pfield_extended.number_of_additional_fractional_time_unit_octets)))
FullPacketCUCWithPField = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeCUCWithPField,
'payload' / IfThenElse(this.timestamp.pfield.pfield_extension == 0,
Byte[
this.primary.data_length - 2 - this.timestamp.pfield.number_of_basic_time_unit_octets -
this.timestamp.pfield.number_of_fractional_time_unit_octets],
Byte[
this.primary.data_length - 3 - this.timestamp.pfield.number_of_basic_time_unit_octets - this.timestamp.pfield.number_of_fractional_time_unit_octets -
this.timestamp.pfield_extended.number_of_additional_basic_time_unit_octets - this.timestamp.pfield_extended.number_of_additional_fractional_time_unit_octets]))
TimeCodeCUCNoPField = Struct('basic_time_unit' / BytesInteger(this._._.num_of_basic_time_units),
'fractional_time_unit' / BytesInteger(this._._.num_of_fractional_time_units))
FullPacketCUCNoPField = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeCUCNoPField,
'payload' / Byte[this.primary.data_length - this._.num_of_basic_time_units -
this._.num_of_fractional_time_units])
#########################################
## CDS related structs
#########################################
PFieldCDS = BitStruct('pfield_extension' / Flag,
'time_code_identification' / BitsInteger(3),
'epoch_identification' / BitsInteger(1),
'length_of_day_segment' / BitsInteger(1),
'length_of_submillisecond_segment' / BitsInteger(2))
TimeCodeCDSWithPField = Struct('pfield' / PFieldCDS,
'days' / BytesInteger(2 + this.pfield.length_of_day_segment),
'ms_of_day' / BytesInteger(4),
'submilliseconds_of_ms' / BytesInteger(2 * this.pfield.length_of_submillisecond_segment))
FullPacketCDSWithPField = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeCDSWithPField,
'payload' / Byte[
this.primary.data_length - 7 - this.timestamp.pfield.length_of_day_segment -
2 * this.timestamp.pfield.length_of_submillisecond_segment])
TimeCodeCDSNoPField = Struct('days' / BytesInteger(2 + this._._.length_of_day_segment),
'ms_of_day' / BytesInteger(4),
'submilliseconds_of_ms' / BytesInteger(2 * this._._.length_of_submillisecond_segment))
FullPacketCDSNoPField = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeCDSNoPField,
'payload' / Byte[
this.primary.data_length - 6 - this._._.length_of_day_segment - 2 * this._._.length_of_submillisecond_segment])
#########################################
## CCS related structs
#########################################
PFieldCCS = BitStruct('pfield_extension' / Flag,
'time_code_identification' / BitsInteger(3),
'calendar_variation_flag' / Flag,
'resolution' / BitsInteger(3))
TimeCodeCCSWithPField = Struct('pfield' / PFieldCCS,
'year' / BytesInteger(2),
'month' / If(this.pfield.calendar_variation_flag == 0, BytesInteger(1)),
'dayOfMonth' / If(this.pfield.calendar_variation_flag == 0, BytesInteger(1)),
'dayOfYear' / If(this.pfield.calendar_variation_flag == 1, BytesInteger(1)),
'hour' / BytesInteger(1),
'minute' / BytesInteger(1),
'second' / BytesInteger(1),
'subseconds' / Byte[this.pfield.resolution])
FullPacketCCSWithPField = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeCCSWithPField,
'payload' / Byte[this.primary.data_length - 8 - this.timestamp.pfield.resolution])
TimeCodeCCSNoPField = Struct('year' / BytesInteger(2),
'month' / If(this._._.calendar_variation_flag == 0, BytesInteger(1)),
'dayOfMonth' / If(this._._.calendar_variation_flag == 0, BytesInteger(1)),
'dayOfYear' / If(this._._.calendar_variation_flag == 1, BytesInteger(2)),
'hour' / BytesInteger(1),
'minute' / BytesInteger(1),
'second' / BytesInteger(1),
'subseconds' / Byte[this._._.resolution])
FullPacketCCSNoPField = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeCCSNoPField,
'payload' / Byte[this.primary.data_length - 7 - this._.resolution])
#########################################
## ASCII A (Month - Day Format) related structs
#########################################
TimeCodeASCIIA = Struct('yearChar1' / BytesInteger(1),
'yearChar2' / BytesInteger(1),
'yearChar3' / BytesInteger(1),
'yearChar4' / BytesInteger(1),
'hyphen1' / BytesInteger(1),
'monthChar1' / BytesInteger(1),
'monthChar2' / BytesInteger(1),
'hyphen2' / BytesInteger(1),
'dayChar1' / BytesInteger(1),
'dayChar2' / BytesInteger(1),
'calendar_time_separator' / BytesInteger(1),
'hourChar1' / BytesInteger(1),
'hourChar2' / BytesInteger(1),
'colon1' / BytesInteger(1),
'minuteChar1' / BytesInteger(1),
'minuteChar2' / BytesInteger(1),
'colon2' / BytesInteger(1),
'secondChar1' / BytesInteger(1),
'secondChar2' / BytesInteger(1),
'dot' / BytesInteger(1),
'decimal_fraction_of_second' / Byte[this._._.number_of_decimals],
'time_code_terminator' / If(this._._.add_Z == 1, BytesInteger(1)))
FullPacketASCIIA = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeASCIIA,
'payload' / Byte[this.primary.data_length - 20 - this._.number_of_decimals - this._.add_Z])
#########################################
## ASCII B (Day of the year Format) related structs
#########################################
TimeCodeASCIIB = Struct('yearChar1' / BytesInteger(1),
'yearChar2' / BytesInteger(1),
'yearChar3' / BytesInteger(1),
'yearChar4' / BytesInteger(1),
'hyphen1' / BytesInteger(1),
'dayChar1' / BytesInteger(1),
'dayChar2' / BytesInteger(1),
'dayChar3' / BytesInteger(1),
'calendar_time_separator' / BytesInteger(1),
'hourChar1' / BytesInteger(1),
'hourChar2' / BytesInteger(1),
'colon1' / BytesInteger(1),
'minuteChar1' / BytesInteger(1),
'minuteChar2' / BytesInteger(1),
'colon2' / BytesInteger(1),
'secondChar1' / BytesInteger(1),
'secondChar2' / BytesInteger(1),
'dot' / BytesInteger(1),
'decimal_fraction_of_second' / Byte[this._._.number_of_decimals],
'time_code_terminator' / If(1 == this._._.add_Z, BytesInteger(1)))
FullPacketASCIIB = Struct('primary' / PrimaryHeader,
'timestamp' / TimeCodeASCIIB,
'payload' / Byte[
this.primary.data_length - 18 - this._.number_of_decimals - this._.add_Z])
#########################################
## No Time Stamps
#########################################
FullPacketNoTimeStamp = Struct('primary' / PrimaryHeader,
'payload' / Byte[this.primary.data_length])
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