Ccsds 2020 b 2 page a 3 ccsds historical document

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: d by the layer below. FARM-B COUNTER: A counter, reported in the CLCW, which increments once for every Type-B frame that is accepted by the FARM on a particular Virtual Channel. CCSDS 202.0-B-2 Page A-3 CCSDS HISTORICAL DOCUMENT November 1992 CCSDS HISTORICAL DOCUMENT CCSDS RECOMMENDATION FOR TELECOMMAND: DATA ROUTING SERVICE FILL DATA: Extra trailing octets of meaningless data added by the sending end Coding layer to complete the last TC Codeblock. Because information in the TC Transfer Frame is needed by the receiving end to determine how much Fill Data has been added, Fill Data must be removed by the receiving end Transfer layer, not by the receiving end Coding layer. FRAME ACCEPTANCE AND REPORTING MECHANISM (FARM): The FARM is the set of procedures executed by the receiving end of the Transfer layer to decide whether to accept a TC Transfer Frame and how to report operation and status back to the FOP via Command Link Control Words. FRAME OPERATION PROCEDURE (FOP): The FOP is the procedure executed by the sending end of the Transfer layer to transmit a TC Transfer Frame. The FOP conducts a transfer sequence using the communication services of the underlying TC Channel Service. Actions of the FOP are dictated by the rules of the COP and the FARM status information passed back to it via the telemetered Command Link Control Word (CLCW). FRAME SEQUENCE NUMBER N(S): The up-counting absolute number that is placed into each Type-A TC Frame. FRAME VALIDATION CHECK: A set of common integrity and quality tests to which ALL TC Transfer Frames are first subjected when they are processed by the receiving end of the Transfer layer. LOCKOUT: A condition whereby the FARM has detected a severe sequentiality anomaly and rejects all subsequent Type-A frames until reset by a Type-B UNLOCK Control Command. MULTIPLEXER ACCESS POINT (MAP): A MAP is a mechanism provided within the Segmentation layer to allow different user data structures to be multiplexed together for transmission on one Virtual Channel pr...
View Full Document

This document was uploaded on 03/06/2014.

Ask a homework question - tutors are online