Version 0.4.0

## Usage

``` python

from SCOS.SCOS import *

from SCOS.SCOS import SCOS

a = SCOS(packet)

```

where *packet* is the hexadecimal string rapresentation of the Telemetry packet.

## Limitation

at the moment the software works only for Telemetry and Telecommand packets (Packet Types 1 and 2) for the BepiColombo ESA Mission. In the next versions other missions will be implemented.

At the moment the software works only for Telemetry and Telecommand packets (Packet Types 1 and 2) for the BepiColombo ESA Mission.

It is possible add a new Mission ID and Spcecraft ID. For example to add the JUICE Mission :

``` python

form SCOS.SCOS import SCOS, MissionID, SpacecraftID

MissionID[844]={'id':844, 'description': 'JUICE'}

SpacecraftID[844]={'id':844, 'description': 'JUICE'}

obj=SCOS[data]

```

In the next versions other missions will be implemented.

## Data Structure

The SCOS object contain:

* **Common Packet Header Structure (CPH)**

* [**Common Packet Header Structure (CPH)**](#common-packet-header-structure-chp)

and one of the following sub-object:

* **Telemetry Packet Header (TMPH)**

* **Telecommand Packet Header (TCPH)**

* **Event Packet Header (EPH)**

* [**Telemetry Packet Header (TMPH)**](#telemetry-packet-header-tmph)

* [**Telecommand Packet Header (TCPH)**](#telecommand-packet-header-tcph)

* [**Event Packet Header (EPH)**](#event-packet-header-eph) (not implemented)

Many of the entries of the objects are dictionary. Usually the structure is the following: *{'id': x, 'description': 'blablabla'}* ad is reported in the tables.

### Common Packet Header Structure (CHP)

In the CHP are present the following fields.

<table>

<tr><th>Field</th><th>Description</th></tr>

<tr><th> CTree </th><td>Used in earlier version of SCOS-2000 by c-tree to support packets storing in files and be kept for backward compatibility.</td></tr>

<tr><th>AccessF</th><td>Storing mode, values are:

* 0 for an inserted packet;

* 1 for an update

</td></tr>

<tr><th>SimFlag</th><td>Simulated packet, values are:

* 0 for a non-simulated packet generated by the spacecraft

* 1 for a simulated packet generated by a Simulator or test tool.

</td></tr>

<tr><th>FilingTime</th><td>Filing Time. For TM this is the timestamp. For TCs, this is the release time.</td></tr>

<tr><th>CreationTime</th><td>Creation Time (in seconds since 1st Jan 1970 00:00:00) – this is a secondary retrieval key and for TM is the time at which the SCOS-2000 packet was

  created, which is also approximately the time that the packet was received by the MCS and stored.

  For TCs, this is its (estimated) execution time</td></tr>

  <tr><th>CreateID</th><td>Used by the old SCOS-2000 archive for generating a retrieval key and set by the application which generated the packet</td></tr>

  <tr><th>SCID</th><td>In the case of telemetry, Spacecraft ID. <br/>

    It has two fields:

    <table>

      <tr><td> ID </td><td> Numeric identificative</td><tr>

      <tr><td> Descriprion <td>Name of the Spacraft</td></tr>

    </table>

    The possible values are in the following table:

    <table>

      <tr><th>ID</th><th>Spacecraft</th></tr>

      <tr><td> 816 </td><td> BepiColombo, TM received over X-Band </td></tr>

      <tr><td> 817 </td><td> BepiColombo, TM received over Ka-Band </td></tr>

    </table>

    </td></tr>

    <tr><th>GSID</th><td> In the case of telemetry, the ID and name of the ground station which receives the frame containing this packet.<br/>

      It has two fields:

      <table>

        <tr><th>ID</th><td> Numeric identificative</td><tr>

        <tr><th>Station<td>Name of the Ground Station</td></tr>

      </table>

      The possible values are in the following table:

      <table>

        <tr><th>ID</th><th>Ground Station Name</th></tr>

        <tr><td> 21 </td><td> Kourou </td></tr>

        <tr><td> 22 </td><td> Perth </td></tr>

        <tr><td> 23 </td><td> New Norcia </td><tr>

        <tr><td> 24 </td><td> Cebreros </td></tr>

        <tr><td> 25 </td><td> Malargue </td></tr>

        <tr><td> 30 </td><td> Maspalomas </td></tr>

        <tr><td> 97 </td><td> Usuda </td></tr>

        <tr><td> 98 </td><td> Uchinoura </td><tr>

      </table>

    </td></tr>

    <tr><th>PSize</th><td>Packet Size. Size of the entire SCOS-2000 packet, including all headers and the packet data.</td></tr>

    <tr><th>PType</th><td>Determines the type of SCOS-2000 packet. See :ref:packet_type for details.

      <table>

        <tr><th>ID</th><th>Description</th></tr>

        <tr><td> 1 </td><td> Telemetry </td></tr>

        <tr><td> 2 </td><td> Telecommand </td></tr>

        <tr><td> 3 </td><td> Event </td></tr>

      </table>

    </td></tr>

    <tr><th>Version</th><td>The version of this packet structure.</td></tr>

    <tr><th>FilingFlag</th><td>Set to **1** if this packet is to be filed in the MCS archive, otherwise **0**.</td></tr>

    <tr><th>DistFlag</th><td>Set to : **1** if this packet is to be distributed to the MCS applications, otherwise **0**.</td></tr>

    <tr><th>TSPolicy</th><td>Determines the timestamp policy for spacecraft TM, i.e. what will be set in the Filing Time fields above:

      <table>

        <tr><th>0</th><td>packet is time-stamped with the creation time – i.e. SCOS-2000 packet creation</td></tr>

        <tr><th>1</th><td>that the packet is time-stamped with the time of transmission of the frame it was received in, i.e. Earth Reception Time minus the propagation delay (applicable to spacecraft TM only)</td></tr>

        <tr><th>2</th><td>the correlated SCET (for spacecraft TM only)</td></tr>

      </table>

    </td></tr>

    <tr><th>TQ</th><td>Time quality of the timestamp, used only if the TsPolicy is set to 2:

      <table>

        <tr><th>0</th><td>Good</td></tr>

        <tr><th>1</th><td>Inaccurate</td></tr>

        <tr><th>2</th><td>Bad</td></tr>

      </table>

    </td></tr>

    <tr><th>StreamID</th><td>The datastream identifier in the MCS, which for TM maps to VCs:

      <table>

        <tr><th>1000</th><td>VC0 Real-Time Non-Science (online)</td></tr>

        <tr><th>1001</th><td>VC1 Playback Non-Science (online)</td></tr>

        <tr><th>1002</th><td>VC2 Science (online)</td></tr>

        <tr><th>1003</th><td>VC3 File-Transfer (online)</td></tr>

        <tr><th>2000</th><td>VC0 Real-Time Non-Science (offline)</td></tr>

        <tr><th>2001</th><td>VC1 Playback Non-Science (offline)</td></tr>

        <tr><th>2002</th><td>VC1 Playback Non-Science (offline)</td></tr>

        <tr><th>2003</th><td>VC2 Science (offline)</td></tr>

        <tr><td colspan="2"> For TCs stream **1** is used.</td></tr>

        <tr><td colspan="2"> For EVs stream **1000** and **1001** is used.</td></tr>

        <tr><th>65535</th><td>is used for internal non spacecraft TM packets, which should be ignored by external users.</td></tr>

      </table>

    </td></tr>

    <tr><th>SeqCounter</th><td>Internal MCS counter used for detecting gaps – not related to the spacecraft source sequence count value in the PUS header</td></tr>

    <tr><th>SPID</th><td>the numerical packet ID which identifies the packet structure, and maps to packet definitions in the TM/TC MIB database. Note: For TC packets, SPIDs 100 and 200 are used.</td></tr>

    <tr><th>MissionID</th><td>For telemetry, the MCS mission identifier.

          <table>

        <tr><th>ID</th><th>Mission</th></tr>

        <tr> <td> **816** </td><td> BepiColombo </td></tr>

      </table>

    </td></tr>

</table>

Field |Description

---|---

**CTree** | Used in earlier version of SCOS-2000 by c-tree to support packets storing in files and be kept for backward compatibility.

**AccessF** | Storing mode, see [Access Flag Table](#access-flag-table)

**SimFlag** | Simulated packet, see [Simulated Packet Table](#simulated-packet-table)

**FilingTime** |Filing Time. For TM this is the timestamp. For TCs, this is the release time.

**CreationTime** | Creation Time. This is a secondary retrieval key and for TM is the time at which the SCOS-2000 packet was created, which is also approximately the time that the packet was received by the MCS and stored. For TCs, this is its (estimated) execution time.

**CreateID** | Used by the old SCOS-2000 archive for generating a retrieval key and set by the application which generated the packet.

**SCID** | In the case of telemetry, Spacecraft ID. See [Spacecraft ID Table](#spacecraft-id-table)

**GSID** | In the case of telemetry, the ID and name of the ground station which receives the frame containing this packet. See [Ground Stations Table](#ground-stations-table)

**PSize** | Packet Size. Size of the entire SCOS-2000 packet, including all headers and the packet data.

**PType** | Determines the type of SCOS-2000 packet. See [Packet Types Table](#packet-types-table)

**Version** | The version of this packet structure.

**FilingFlag** | Set to **1** if this packet is to be filed in the MCS archive, otherwise **0**.

**DistFlag** | Set to : **1** if this packet is to be distributed to the MCS applications, otherwise **0**.

**TSPolicy** | Determines the timestamp policy for spacecraft TM, i.e. what will be set in the Filing Time fields above. See [Timestamp Policy Table](#timestamp-policy-table)

**TQ** | Time quality of the timestamp, used only if the **TsPolicy** is set to **2**. See [Time Quality Table](#time-quality-table).

**StreamID** | The datastream identifier in the MCS, which for TM maps to VCs. See [Stream IDs Table](#stream-ids-table)

**SeqCounter** | Internal MCS counter used for detecting gaps – not related to the spacecraft source sequence count value in the PUS header.

**SPID** | the numerical packet ID which identifies the packet structure, and maps to packet definitions in the TM/TC MIB database. Note: For TC packets, SPIDs 100 and 200 are used.

**MissionID** | For telemetry, the MCS mission identifier. See [Mission IDs Table](#mission-ids-table)

#### Access Flag Table

ID | Description

---|---

**0** |  inserted packet

**1** | update

#### Simulated Packet Table

ID | Description

---|---

**0** | non-simulated packet generated by the spacecraft

**1** | simulated packet generated by a Simulator or test tool.

#### Spacecraft ID Table

ID | Spacecraft | Band

---|---|---

**816** | BepiColombo | TM received over X-Band.

**817** | BepiColombo | TM received over Ka-Band.

#### Ground Stations Table

ID | Description

---|---

**21** | Kourou 

**22** | Perth 

**23** | New Norcia

**24** | Cebreros 

**25** | Malargue 

**30** | Maspalomas 

**97** | Usuda 

**98** | Uchinoura 

#### Packet Types Table

ID | Description

---|---

**1** | Telemetry 

**2** | Telecommand 

**3** | Event 

#### Timestamp Policy Table

ID | Description

---|---

**0** | packet is time-stamped with the creation time – i.e. SCOS-2000 packet creation

**1** | The packet is time-stamped with the time of transmission of the frame it was received in, i.e. Earth Reception Time minus the propagation delay (applicable to spacecraft TM only)

**2** | the correlated SCET (for spacecraft TM only)

#### Time Quality Table

ID | Description

---|---

**0** | Good

**1** | Inaccurate

**2** | Bad

#### Stream IDs Table

ID | Description

---:|---

**1** | Used for TC stream

**1000** | VC0 Real-Time Non-Science (online)

**1001** | VC1 Playback Non-Science (online)

**1002** | VC2 Science (online)

**1003** | VC3 File-Transfer (online)

**2000** | VC0 Real-Time Non-Science (offline)

**2001** | VC1 Playback Non-Science (offline)

**2002** | VC1 Playback Non-Science (offline)

**2003** | VC2 Science (offline)

**65535** | is used for internal non spacecraft TM packets, which should be ignored by external users.

For EVs stream **1000** and **1001** are used.

#### Mission IDs Table

ID | Mission

---|---

**816** | BepiColombo 

### Telemetry Packet Header (TMPH)

If the _**CHP.PType**_ is equal to 1, the packet is a telemetry. In this case is present the TMPH onject.

The object has the following structure:

<table>

  <tr><th> Attribute </th><th>Description </th></tr>

  <tr><td>

  **TPSD**

  </td><td>Structure identifier for variable length packets.</td></tr>

  <tr><td>

  **RouteID** </td><td>The LSB of the RouteID field is used by SCOS-2000 to identify the Data Unit Type of Telemetry packet and its qualifier</td></tr>

  <tr><td> **PUSAPID** </td><td>The value of the 11-bit Application Process ID, copied from the spacecraft source packet’s primary header</td></tr>

  <tr><td>**PUSSSC**</td><td>The value of the 14-bit Source Sequence Count, copied from the spacecraft source packet’s primary header</td></tr>

  <tr><td>**PUSST**</td><td>The value of the 8-bit Service Type, copied from the spacecraft source packet’s secondary data field header</td></tr>

  <tr><td>**PUSSST**</td><td>The value of the 8-bit Service Sub-type, copied from the spacecraft source packet’s secondary data field header</td></tr>

</table>

Attribute|Description

---|---

**TPSD**|Structure identifier for variable length packets.

**RouteID** |The LSB of the RouteID field is used by SCOS-2000 to identify the Data Unit Type of Telemetry packet and its qualifier

**PUSAPID** |The value of the 11-bit Application Process ID, copied from the spacecraft source packet’s primary header

**PUSSSC** |The value of the 14-bit Source Sequence Count, copied from the spacecraft source packet’s primary header

**PUSService** |The value of the 8-bit Service Type, copied from the spacecraft source packet’s secondary data field header. The old key *PUSST* is deprecated.

**PUSSubService** |The value of the 8-bit Service Sub-type, copied from the spacecraft source packet’s secondary data field header. The old key *PUSSST* is deprecated.

### Telecommand Packet Header (TCPH)

If the _**CHP.PType**_ is equal to 2, the packet is a telecommand. In this case is present the TCPH onject.

The object has the following structure:

<table>

  <tr><th>Attribute</th><th>Descriprion</th></tr>

  <tr><td>

  **UplinkTime** </td><td> Uplink Time – initially set to the release time (FT), but updated with the timestamp copied from the radiation ground station response message providing the actual time of uplink from the antenna</td></tr>

  <tr> <td> **ExecTime** </td><td> Execution Time – For time-tagged commands this is the UTC user provided execution time. For immediate commands this is the release time + propagation delay and later updated to be Uplink time + propagation delay</td></tr>

  <tr><td> **LUTime** </td><td> Last Update Time, this is the MCS system time at which the TC packet was last updated with a change of status</td></tr>

  <tr><td> **RequestID** </td><td> Internal MCS identifier.</td></tr>

  <tr><td> **ReqElemIdx** </td><td> Internal MCS sub-identifier.</td><tr>

  <tr><td> **VarAddSz** </td><td> Combined size of the fixed and variable parts of the command details data.</td></tr>

  <tr><td> **PUSAPID** </td><td> The value of the 11-bit Application Process ID, copied from the spacecraft source packet’s primary header</td></tr>

  <tr><td> **PID** </td><td> Process ID</td></tr>

  <tr><td> **PCAT** </td><td> Packet Category</td></tr>

  <tr><td> **PUSSSC** </td><td> The value of the 14-bit Sequence Count, copied from the spacecraft source packet’s primary header</td></tr>

  <tr><td> **PUSST** </td><td> Service Type - The value of the 8-bit Service Type, copied from the spacecraft source

packet’s secondary data field header.</td></tr>

  <tr><td> **PUSSST** </td><td> Sub-Service Type - The value of the 8-bit Service Sub-type, copied from the spacecraft source packet’s secondary data field header</td></tr>

  <tr><td> **PUSAck** </td><td> The value of the 4-bit Ack, copied from the spacecraft source packet’s secondary data field header

  <table>

    <tr><td> **0** </td><td>No Acknowledge required for acceptance and execution</td></tr>

    <tr><td> **1** </td><td>Acknowledge required for acceptance </td></tr>

    <tr><td> **8** </td><td>Acknowledge required for execution </td></tr>

    <tr><td> **9** </td><td>Acknowledge required for acceptance and execution</td></tr>

  </table>

  </td></tr>

  <tr><td> **UplinkFlag** </td><td>

    <table>

      <tr><td> **1** </td><td> if the command is to be released (passed PTV)</td><tr>

      <tr><td> **0** </td><td> if the command is not to be released (failed PTV)</td></tr>

    </table>

  </td></tr>

  <tr><td> **SourceHost** </td><td> Numerical ID of the MCS machine running the command source.</td></tr>

  <tr><td> **SourceType** </td><td> Enumeration providing the type of the command source</td></tr>

  <tr><td> **ReqDetFixedSize** </td><td> Size of the fixed part of the command details data.</td></tr>

Attribute | Descriprion

---|---

**UplinkTime** | Uplink Time – initially set to the release time (FT), but updated with the timestamp copied from the radiation ground station response message providing the actual time of uplink from the antenna.

**ExecTime** | Execution Time – For time-tagged commands this is the UTC user provided execution time. For immediate commands this is the release time + propagation delay and later updated to be Uplink time + propagation delay.

**LUTime** | Last Update Time, this is the MCS system time at which the TC packet was last updated with a change of status.

**RequestID** | Internal MCS identifier.

**ReqElemIdx** | Internal MCS sub-identifier.

**VarAddSz** | Combined size of the fixed and variable parts of the command details data.

**PUSAPID** | The value of the 11-bit Application Process ID, copied from the spacecraft source packet’s primary header.

**PID** | Process ID.

**PCAT** | Packet Category.

**PUSSSC** | The value of the 14-bit Sequence Count, copied from the spacecraft source packet’s primary header.

**PUSService** | Service Type - The value of the 8-bit Service Type, copied from the spacecraft source packet’s secondary data field header. The old key ***PUSST*** is deprecated.

**PUSSubService**  | Sub-Service Type - The value of the 8-bit Service Sub-type, copied from the spacecraft source packet’s secondary data field header. The old key ***PUSSST*** is deprecated.

**PUSAck** | The value of the 4-bit Ack, copied from the spacecraft source packet’s secondary data field header. See [Aknowledge Table](#aknowledge-table).

**UplinkFlag** | Uplink Flag. See [Uplink Codes Table](#uplink-codes-table).

**SourceHost** | Numerical ID of the MCS machine running the command source.

**SourceType** | Enumeration providing the type of the command source.

**ReqDetFixedSize** | Size of the fixed part of the command details data.

</table>

#### Aknowledge Table

ID | Description

---|---

**0**  | No Acknowledge required for acceptance and execution.

**1** | Acknowledge required for acceptance. 

**8**  | Acknowledge required for execution

**9** | Acknowledge required for acceptance and execution

#### Uplink Codes Table

ID | Description

---|---

**1** | if the command is to be released (passed PTV)

**0** | if the command is not to be released (failed PTV)

### Event Packet Header (EPH)

If the _**CHP.PType**_ is equal to 3, the packet is a event. In this case is present the EPH onject.

## Change Log

### Version 0.4.0

+ the fields of the subobject are now dict type.

+ improved prefomace

+ implemented the method to add a new mission dinamically.

### Version 0.3.0

+ tested on Python 3

+ minor bug fixef

### Version 0.2.2

+ bug fix, old call to database removed

+ update of the user manual