Space engineering
Adoption Notice of CCSDS 232.1-B-2, Communications Operation Procedure-1
Foreword
This Adoption Notice is one document of the series of ECSS Standards intended to be applied together for the management, engineering, product assurance and sustainability in space projects and applications. ECSS is a cooperative effort of the European Space Agency, national space agencies and European industry associations for the purpose of developing and maintaining common standards. Requirements in this Standard are defined in terms of what shall be accomplished, rather than in terms of how to organize and perform the necessary work. This allows existing organizational structures and methods to be applied where they are effective, and for the structures and methods to evolve as necessary without rewriting the standards.
This Adoption Notice has been prepared by the ECSS Space Communications Working Group, reviewed by the ECSS Executive Secretariat and approved by the ECSS Technical Authority.
Disclaimer
ECSS does not provide any warranty whatsoever, whether expressed, implied, or statutory, including, but not limited to, any warranty of merchantability or fitness for a particular purpose or any warranty that the contents of the item are error-free. In no respect shall ECSS incur any liability for any damages, including, but not limited to, direct, indirect, special, or consequential damages arising out of, resulting from, or in any way connected to the use of this document, whether or not based upon warranty, business agreement, tort, or otherwise; whether or not injury was sustained by persons or property or otherwise; and whether or not loss was sustained from, or arose out of, the results of, the item, or any services that may be provided by ECSS.
Published by: ESA Requirements and Standards Section ESTEC, P.O. Box 299, 2200 AG Noordwijk The Copyright: 2021© by the European Space Agency for the members of ECSS## Change log
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ECSS-E-AS-50-26C
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First issue
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Scope
This document identifies the clauses and requirements modified with respect to the standards CCSDS 232.1-B-2, Communications Operation Procedure-1, Issue 2, September 2010 for application in ECSS.
The recently published technical corrigendum has modified CCSDS 232.1-B-2. However, the changes are not affecting the AS.
Context information
The standard CCSDS 232.1-B-2, Communications Operation Procedure-1, Issue 2, has been developed by CCSDS in support of CCSDS 232.0-B-3, TC Space Data Link Protocol, adopted by ECSS with ECSS-E-AS-50-25C.
In the standard CCSDS 232.0-B-3, TC Space Data Link Protocol, CCSDS specifies a data link layer protocol for the efficient transfer of space application data of various types and characteristics over ground-to-space links. The Communications Operation Procedure-1 (COP-1) specified in CCSDS 232.1-B-2 is used with the TC Space Data Link Protocol: it provides a mechanism for delivery of frames in sequence and without gaps or duplication.
With this Adoption Notice ECSS is adopting and applying CCSDS 232.1-B-2 with a minimum set of modifications, identified in the present document, to allow for reference and for a consistent integration in the ECSS system of standards.
The COP-1 protocol of CCSDS 232.1-B-2 was specified in clause 7 (COP-1) of ECSS-E-ST-50-04 Space data links – Telecommand protocols synchronization and channel coding, that is superseded by this Adoption Notice together with the following two Adoption Notices: ECSS-E-ST-50-24C and ECSS-E-AS-50-25C.
Differences between this Adoption Note and the relevant part of ECSS-E-ST-50-04 that are not covered by the normative modifications in clause 4 are described in the informative Annex A.
Overview of superseded ECSS-E-50-xx Standards
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Superseded ECSS
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ECSS Adopted Notice
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Based on CCSDS
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ECSS-E-ST-50-01C
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ECSS-E-AS-50-21C
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CCSDS 131.0-B-3 (Sept. 2017)
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ECSS-E-ST-50-03C
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ECSS-E-AS-50-22C
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CCSDS 132.0-B-2 (Sept. 2015)
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ECSS-E-AS-50-23C
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CCSDS 732.0-B-3 (August 2016)
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ECSS-E-ST-50-04C
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ECSS-E-AS-50-24C
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CCSDS 231.0-B-3 (Sept. 2017)
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ECSS-E-AS-50-25C
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CCSDS 232.0-B-3 (Sept. 2015)
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ECSS-E-AS-50-26C
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CCSDS 232.1-B-2 (Sept. 2010)
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Abbreviated terms
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Abbreviation
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Meaning
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COP
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Communications Operation Procedure
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FARM
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Frame Acceptance and Reporting Mechanism
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FDU
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Frame Data Unit
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GVCID
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Global Virtual Channel Identifier
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SDLS
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Space Data Link Security
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Application requirements
CCSDS 232.1-B-2, Communications Operation Procedure-1, Issue 2, September 2010 shall apply with the following modifications listed in Table 41.
Table 41: Applicability table for CCSDS 232.1-B-2
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Clause or requirement number |
Applicability |
Applicable text (the new/added text is underlined) |
Comments |
Text as in the original document (deleted text with strikethrough) |
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3rd and 4th paragraphs of 3.3.2 |
Modified |
When a Type-BD Transfer Frame is accepted by FARM-1, the FDU contained in the Transfer Frame shall be placed in a buffer for delivery to the Higher Procedures even if there is no buffer available, in which case the data in the buffer is erased. When a new FDU is accepted, FARM-1 shall send the following signal to the Higher Procedures to indicate the arrival of the new FDU:FDU Arrived Indication (GVCID, FDU aborted indication). |
Requirements in 1st and 2nd paragraphs of 3.3.2 are not shown here and are unchanged. CCSDS requirement modified: words “will be erased and an optional ‘Aborted Indication’ signal may be sent to the Higher Procedures” deleted and replaced by words “is erased”. Words “FDU aborted indication” added. |
When a Type-BD Transfer Frame is accepted by FARM-1, the FDU contained in the Transfer Frame shall be placed in a buffer for delivery to the Higher Procedures even if there is no buffer available, in which case the data in the buffer will be erased and an optional ‘Aborted Indication’ signal may be sent to the Higher Procedures. When a new FDU is accepted, FARM-1 shall send the following signal to the Higher Procedures to indicate the arrival of the new FDU:FDU Arrived Indication (GVCID). |
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new paragraph following 4th paragraph of 3.3.2 |
New requirement |
The FDU aborted indication shall be used as follows:- the indication is set when a Type-BD Transfer Frame is accepted by FARM-1 and there is no buffer available;- the indication is otherwise not set. |
New requirement added |
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Note 2 in 3.3.2 |
Modified (NOTE) |
When the FDU aborted indication is set, it informs the Higher Procedures that data in the buffer have been erased in favour of the newly arrived Type-BD Transfer Frame. |
CCSDS NOTE modified for Type-BD Transfer Frame. New sentence added to replace the sentence “In addition to the ‘FDU Arrived Indication’, FARM-1 may optionally send a signal called ‘Aborted Indication’ to the Higher Procedures when data that were previously contained in a buffer have been erased in favour of the newly received FDU. This Recommended Standard does not specify how this signal is delivered.” that has been deleted. |
In addition to the ‘FDU Arrived Indication’, FARM-1 may optionally send a signal called ‘Aborted Indication’ to the Higher Procedures when data that were previously contained in a buffer have been erased in favour of the newly received FDU. This Recommended Standard does not specify how this signal is delivered. |
ANNEX(informative)Differences from ECSS-E-ST-50-04C
General
Clause 4 of this document contains normative additions and modifications concerning some of the differences between CCSDS 232.1-B-2 and ECSS-E-ST-50-04 (superseded by this AS ECSS-E-AS-50-232.1-B-2). This Annex describes some additional differences that are not covered by Clause 4.
This Annex lists the differences of technical content, but it is not the purpose of this Annex to provide complete details on each item in the list or to describe the consequences of each item in the list.
Differences
FARM-1 with single back-end buffer
Clause 7 of ECSS-E-ST-50-04 had requirements for a FARM‐1 implementation that provides only one back‐end buffer for a virtual channel. This special case is not included in CCSDS 232.1-B-2.
Bibliography
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ECSS-E-AS-50-21C
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Space engineering - Adoption Notice of CCSDS 131.0-B-3, TM Synchronization and Channel Coding
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ECSS-E-AS-50-22C
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Space engineering - Adoption Notice of CCSDS 132.0-B-2, TM Space Data Link Protocol
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ECSS-E-AS-50-23C
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Space engineering -Adoption Notice of CCSDS 732.0-B-3, AOS Space Data Link Protocol
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ECSS-E-AS-50-24C
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Space engineering - Adoption Notice of CCSDS 231.0-B-3, TC Synchronization and Channel Coding
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ECSS-E-AS-50-25C
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Space engineering - Adoption Notice of CCSDS 232.0-B-3, TC Space Data Link Protocol
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ECSS-E-AS-50-26C
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Space engineering - Adoption Notice of CCSDS 232.1-B-2, Communications Operation Procedure-1
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ECSS-E-ST-50-01C
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Space engineering - Space data links - Telemetry synchronization and channel coding
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ECSS-E-ST-50-03C
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Space engineering - Space data links - Telemetry transfer frame protocol
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ECSS-E-ST-50-04C
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Space engineering - Space data links - Telecommand protocols synchronization and channel coding
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CCSDS 230.1-G-2
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TC Synchronization and Channel Coding, Summary of Concept and Rationale – Green Book, Issue 2, November 2012
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