EIR-OPS-011: Downlink Data From Storage

Objective

To downlink the contents of an on-board storage channel.

Introduction

Using this procedure, the Operator will downlink multiple rows of data from a specific on-board storage channel.

Procedure

This procedure contains the following sub-procedures:

A. Pre-Pass Preparations
B. Tx Convolutional Encoding Management
C. Data Downlink
D. Post-Pass Close-out

Note

Communication with the spacecraft is required for Sections B - C of this procedure.

A. Pre-Pass Preparations

A.1.

The Operator should now open ROW . This Google Sheet aims to help the Operator to quickly determine what First Row and Last Row values to use when downlinking data from core.storage.channelContent in the next sections of this procedure.
To use this tool, the Operator must provide information from previous passes and so, this Google Sheet should be reviewed and filled-in as required prior to the up-coming pass, with the following questions in mind:
- What data type(s) do you want to downlink?
- What percentage of the pass time do you want to allocate to downlinking the different data types?
- If constrained by the time, do you want to give priority to the newest or oldest rows of data?

A.2.

The Operator should also now take note of the cdh.logging.XXXLogger path(s) required to obtain the AbsRowsLogged parameter(s) in Step C.1, as well as the Channel ID(s) required for the Downlink TC in Step C.3. This information is provided in ROW .

B. Tx Convolutional Encoding Management

Important

To increase throughput when downlinking large amounts of data, Tx convolutional encoding should be disabled. To ensure good communication while encoding is disabled, the Z-axis MTQ cannot be active. Therefore, it will be necessary to place the ADCS into Standby Mode during this time. TimeActions will be used to return the ADCS and comms configurations to normal after the pass. This section of the procedure should only be carried out ONCE PER PASS.

Tip

If the Operators only intend to downlink a small quantity of data, this section may be skipped if it is acceptable that the downlink occurs at half the rate.

Warning

This section of the procedure SHOULD NOT BE FOLLOWED during the initial passes of the mission, until the GS team confirm that 2-way communications is sufficiently stable.

ADCS Mode TimeAction

Important

You are about to send the first TC of this procedure - Have you completed the EIR-OPS-003: Start a Communication Pass procedure? A Communication Pass must be started prior to carrying out the operations planned for the pass. Don’t forget to set up the parameters/actions that will be used during the pass in MCS before the pass begins!

B.1.

Get the parameter platform.ADCS.adcsModeState to determine the current ADCS mode and state.
Note the data returned for use in the next steps.

TC Details
MCS Operation	`Get`
Action/Param Name	`platform.ADCS.adcsModeState`
Data Expected with TC	No
TM Details
Data Expected from TC	`adcsModeState` ( + ACK )
Data Size	4 bytes
Data Info	The current mode (2 MSB) and state (2 LSB) of the ADCS
Allowed Value(s)	See tables below

Where…

`adcsMode` (hex)	ADCS Mode
0000	Standby (Default)
0001	Detumble
0002	Spin Stabilised
5550	Test

`adcsState` (hex)	ADCS State
0000	Nadir (Default)
AAA8	Test

B.2.

If:
- Commissioning of the spacecraft is on-going, proceed to Step D.1 (unless instructed otherwise) as we do not want to disable convolutional encoding during this time.
- adcsModeState = 5550AAA8 (hex), proceed to Step D.1 as we do not want to disable Tx convolutional encoding during test/WBC activities with the ADCS.
- adcsModeState = 00000000 (hex), proceed to Step B.13 as the ADCS is already operating in Stand-by Mode.

Warning

If failsafe is the current boot image when following this procedure, the action argument should instead = 0 in this step.

Else, Invoke the cdh.scheduling.TimeAction.restartRelativeEntries action with the action argument = 1.

TC Details
MCS Operation	`Invoke`
Action/Param Name	`cdh.scheduling.TimeAction.restartRelativeEntries`
Data Expected with TC	`rows`
Data Size	1 byte
Data Info	The index of the relative entry to restart
Allowed Value(s)	0 - 255 (dec)
Expected Value(s)	1
TM Details
Data Expected from TC	No ( + ACK )

B.3.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 0 should instead be used in this step.

Get the cdh.scheduling.TimeAction.entryListPacked parameter with First row = Last row = 1.
Take note of the last 4 bytes (i.e. the last 8 hex characters) of this parameter, which follow ‘04’ when viewed in hex format, for use in the next step.

TC Details
MCS Operation	`Get`
Action/Param Name	`cdh.scheduling.TimeAction.entryListPacked`
Data Expected with TC	`First Row`, `Last Row`
Data Size	2 bytes, 2 bytes
Data Info	The first and last rows/indexes of the parameter to get
Allowed Value(s)	0 - 511, 0 - 511 (dec)
Expected Value(s)	1, 1
TM Details
Data Expected from TC	`cdh.scheduling.TimeAction.entryListPacked` ( + ACK )
Data Size	19 bytes
Data Info	The schedule entry list as packed records

B.4.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 0 should instead be used in this step.

If the 4 bytes noted in the previous step do not match adcsModeState from Step B.1, edit these bytes in the data field of the cdh.scheduling.TimeAction.entryListPacked parameter window to match adcsModeState from Step B.1 and Set the parameter with First row = Last row = 1.
Else, skip ahead to Step B.6.

TC Details
MCS Operation	`Set`
Action/Param Name	`cdh.scheduling.TimeAction.entryListPacked`
Data Expected with TC	`First Row`, `Last Row`, `entryListPacked`
Data Size	2 bytes, 2 bytes, 19 bytes
Data Info	The first and last rows/indexes of the parameter to set + the desired `entryListPacked` to set
Allowed Value(s)	0 - 511, 0 - 511 (dec), many variation allowed (hex)
Expected Value(s)	1, 1, last 4 bytes = `adcsModeState` (hex)
TM Details
Data Expected from TC	No ( + ACK )

B.5.

Confirm the Set in the previous step with a Get (i.e. confirm the value was set successfully).

B.6.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 0 should instead be used in this step.

Set the cdh.scheduling.TimeAction.entryTime parameter, with First row = Last row = 1, to 600 (dec).

TC Details
MCS Operation	`Set`
Action/Param Name	`cdh.scheduling.TimeAction.entryTime`
Data Expected with TC	`First Row`, `Last Row`, `entryTime`
Data Size	2 bytes, 2 bytes, 4 bytes
Data Info	The first and last rows/indexes of the parameter to set + the desired `entryTime` to set
Allowed Value(s)	0 - 511, 0 - 511 (dec), 00000000 - FFFFFFFF (hex)
Expected Value(s)	1, 1, 600 (dec)
TM Details
Data Expected from TC	No ( + ACK )

B.7.

Confirm the Set in the previous step with a Get (i.e. confirm the value was set successfully).

B.8.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 0 should instead be used in this step.

Prior to enabling this TimeAction, Get the cdh.scheduling.TimeAction.entryEnabled parameter, with First row = Last row = 1.
Ensure that it is 0 (disabled).

TC Details
MCS Operation	`Get`
Action/Param Name	`cdh.scheduling.TimeAction.entryEnabled`
Data Expected with TC	`First Row`, `Last Row`
Data Size	2 bytes, 2 bytes
Data Info	The first and last rows/indexes of the parameter to get
Allowed Value(s)	0 - 511, 0 - 511 (dec)
Expected Value(s)	1, 1
TM Details
Data Expected from TC	`cdh.scheduling.TimeAction.entryEnabled` ( + ACK )
Data Size	boolean
Data Info	Whether the TimeAction entry is enabled (1) or disabled (0)
Allowed Value(s)	0 - 1
Expected Value(s)	0

B.9.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 0 should instead be used in this step.

Set the cdh.scheduling.TimeAction.entryEnabled parameter, with First row = Last row = 1, to 1 (i.e. enabled).

TC Details
MCS Operation	`Set`
Action/Param Name	`cdh.scheduling.TimeAction.entryEnabled`
Data Expected with TC	`First Row`, `Last Row`, `entryEnabled`
Data Size	2 bytes, 2 bytes, boolean
Data Info	The first and last rows/indexes of the parameter to set + the desired `entryEnabled` to set
Allowed Value(s)	0 - 511, 0 - 511, 0 - 1 (dec)
Expected Value(s)	1, 1, 1
TM Details
Data Expected from TC	No ( + ACK )

B.10.

Confirm the Set in the previous step with a Get (i.e. confirm the value was set successfully).

B.11.

Set the parameter platform.ADCS.adcsModeState to 00000000 (hex).

TC Details
MCS Operation	`Set`
Action/Param Name	`platform.ADCS.adcsModeState`
Data Expected with TC	`adcsModeState`
Data Size	4 bytes
Data Info	ADCS Mode and State to set
Allowed Value(s)	See table in Step B.1.
Expected Value(s)	00000000 (hex)
TM Details
Data Expected from TC	No ( + ACK )

B.12.

Confirm the Set in the previous step with a Get (i.e. confirm the value was set successfully).

Tx Convolution Encoding TimeAction

B.13.

Warning

If failsafe is the current boot image when following this procedure, the action argument should instead = 2 in this step.

Invoke the cdh.scheduling.TimeAction.restartRelativeEntries action with the action argument = 3.

TC Details
MCS Operation	`Invoke`
Action/Param Name	`cdh.scheduling.TimeAction.restartRelativeEntries`
Data Expected with TC	`rows`
Data Size	1 byte
Data Info	The index of the relative entry to restart
Allowed Value(s)	0 - 255 (dec)
Expected Value(s)	3
TM Details
Data Expected from TC	No ( + ACK )

B.14.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 2 should instead be used in this step.

Set the cdh.scheduling.TimeAction.entryTime parameter, with First row = Last row = 3, to 600 (dec).

TC Details
MCS Operation	`Set`
Action/Param Name	`cdh.scheduling.TimeAction.entryTime`
Data Expected with TC	`First Row`, `Last Row`, `entryTime`
Data Size	2 bytes, 2 bytes, 4 bytes
Data Info	The first and last rows/indexes of the parameter to set + the desired `entryTime` to set
Allowed Value(s)	0 - 511, 0 - 511 (dec), 00000000 - FFFFFFFF (hex)
Expected Value(s)	3, 3, 600 (dec)
TM Details
Data Expected from TC	No ( + ACK )

B.15.

Confirm the Set in the previous step with a Get (i.e. confirm the value was set successfully).

B.16.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 2 should instead be used in this step.

Prior to enabling this TimeAction, Get the cdh.scheduling.TimeAction.entryEnabled parameter, with First row = Last row = 3.
Ensure that it is 0 (disabled).

TC Details
MCS Operation	`Get`
Action/Param Name	`cdh.scheduling.TimeAction.entryEnabled`
Data Expected with TC	`First Row`, `Last Row`
Data Size	2 bytes, 2 bytes
Data Info	The first and last rows/indexes of the parameter to get
Allowed Value(s)	0 - 511, 0 - 511 (dec)
Expected Value(s)	3, 3
TM Details
Data Expected from TC	`cdh.scheduling.TimeAction.entryEnabled` ( + ACK )
Data Size	boolean
Data Info	Whether the TimeAction entry is enabled (1) or disabled (0)
Allowed Value(s)	0 - 1
Expected Value(s)	0

B.17.

Warning

If failsafe is the current boot image when following this procedure, First row = Last row = 2 should instead be used in this step.

Set the cdh.scheduling.TimeAction.entryEnabled parameter, with First row = Last row = 3, to 1 (i.e. enabled).

TC Details
MCS Operation	`Set`
Action/Param Name	`cdh.scheduling.TimeAction.entryEnabled`
Data Expected with TC	`First Row`, `Last Row`, `entryEnabled`
Data Size	2 bytes, 2 bytes, boolean
Data Info	The first and last rows/indexes of the parameter to set + the desired `entryEnabled` to set
Allowed Value(s)	0 - 511, 0 - 511, 0 - 1 (dec)
Expected Value(s)	3, 3, 1
TM Details
Data Expected from TC	No ( + ACK )

B.18.

Confirm the Set in the previous step with a Get (i.e. confirm the value was set successfully).

B.19.

Get the platform.CMC.txConvEnabled parameter.
Confirm it is 1 (i.e. convolutional encoding is enabled).

TC Details
MCS Operation	`Get`
Action/Param Name	`platform.CMC.txConvEnabled`
Data Expected with TC	No
TM Details
Data Expected from TC	`platform.CMC.txConvEnabled` ( + ACK )
Data Size	Boolean
Data Info	Whether convolutional encoding is enabled (1) or disabled (0)
Allowed Value(s)	0 - 1
Expected Value(s)	1

B.20.

To disable convolutional encoding, Set the platform.CMC.txConvEnabled parameter to 0 (disabled).

TC Details
MCS Operation	`Set`
Action/Param Name	`platform.CMC.txConvEnabled`
Data Expected with TC	`txConvEnabled`
Data Size	Boolean
Data Info	Enable (1) or disable (0) convolutional encoding
Allowed Value(s)	0 - 1
Expected Value(s)	0
TM Details
Data Expected from TC	No ( + ACK )

B.21.

Confirm the Set in the previous step with a Get (i.e. confirm the value was set successfully).

C. Data Downlink

C.1.

Get the cdh.logging.XXXLogger.AbsRowsLogged parameter for the Logger, where XXX = HK, TED, Event, ADCS, etc.

TC Details
MCS Operation	`Get`
Action/Param Name	`cdh.logging.XXXLogger.AbsRowsLogged`
Data Expected with TC	No
TM Details
Data Expected from TC	`cdh.logging.XXXLogger.AbsRowsLogged` ( + ACK )
Data Size	4 bytes
Data Info	The absolute number of rows ever logged to this channel
Allowed Value(s)	0 - FFFFFFFF (hex)

C.2.

Input the TM from the previous step into the relevant cell of ROW . When this value have been provided, the Google Sheet will automatically offer options for First Row and Last Row values to use in the next step.

C.3.

Downlink from the core.storage.channelContent parameter with:
- The Parameter index in block field to equal the ID (in decimal) of the channel from which data is to be downlinked, and
- The First row and Last Row fields to equal the chosen values from Step C.2.

Tip

When Downlink is clicked, MCS will prompt the Operator for a filename. To facilitate starting the LDT promptly, provide a short, temporary filename (e.g. ‘HK’, ‘TED’, etc.). A filename extension is not required.

TC Details
MCS Operation	`Downlink`
Action/Param Name	`core.storage.channelContent`
Data Expected with TC	Yes
Data Size	2 bytes; 2 bytes; 2 bytes
Data Info	`Parameter index in block` = channel ID (in decimal), `First row` and `Last row`
Allowed Value(s)	0001 - FFFF, 0000 - FFFF and 0000 - FFFF (Hex)
TM Details
Data Expected from TC	Data ( + ACK )
Data Size	n bytes, where n = size of requested data
Data Info	Requested data

C.4.

Confirm from the Transfer Window in MCS that the LDT is now on-going.

Warning

LDTs can sometimes fail in an acceptable way, e.g. due to the on-board storage being ‘busy’ when the OBSW attempted to access the requested data. When a transfer is progressing successfully, the Transfer Window should state the the LDT is ‘In progress’ (see Figure 1). However, if a fail occurs and ‘Suspended’ is instead observed, select the LDT in the Transfer Window and click the ‘Resume’ button.

This may happen multiple times but should not happen so frequently that the transfer does not progress by some amount (%) in-between the attempts to resume the transfer. If the transfer persistently fails, do NOT continue with attempts to resume the LDT or with the remainder of the procedure until the Software and/or Systems Engineer have reviewed the issue.

This option to ‘resume’ a failed LDT is only applicable to multi-part LDTs (referred to as ‘Multi-DLink’ LDTs in MCS/Figure 1). Smaller downlinks that do not generate an associated Multi-DLink pane in MCS must be restarted from scratch.

../../../_images/LDTStatus.png — Figure 1 - Transfer Window during an LDT. Top: In progress transfer. Bottom: Suspended transfer.

D. Post-Pass Close-out

D.1.

When the Transfer Window in MCS indicates that the transfer has completed successfully (i.e. when 100/100% is observed in the “Multi D-link” tab, shortly after which the LDT will disappear from the Transfer Window), update the ‘LastPassInfo’ Sheet of ROW with the value of the cdh.logging.XXXLogger.AbsRowsLogged parameter corresponding to the downlinked data.

D.2.

The file saved with a temporary filename in Step C.3. should now be renamed to match the following format

[TYPE]_[YYYYMMDD]_[First Row]_[Last Row]_[AbsRowsLogged corresponding to Last Row],

where [First Row], [Last Row] and [AbsRowsLogged corresponding to Last Row] should be taken from ROW.
This file should then be move to ~/Desktop/DataFromSC.

D.3.

If health check data was downlinked during the pass, this data should now be reviewed, calling on other team members for input where necessary and using, e.g., Grafana. If science data was downlinked, the relevant science teams should be notified.

END OF PROCEDURE