12 transfer frame primary header 4121 general the

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Unformatted text preview: tory); d) Master Channel Frame Count (1 octet, mandatory); e) Virtual Channel Frame Count (1 octet, mandatory); f) Transfer Frame Data Field Status (2 octets, mandatory). The format of the Transfer Frame Primary Header is shown in figure 4-2. CCSDS 132.0-B-1 Page 4-2 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL TRANSFER FRAME PRIMARY HEADER (6 octets) MASTER CHANNEL ID 2 bits 10 bits 3 bits MASTER CHANNEL FRAME COUNT VIRTUAL CHANNEL FRAME COUNT TRANSFER FRAME DATA FIELD STATUS 1 octet VIRTUAL OCF TRANSFER SPACECRAFT CHANNEL FLAG ID FRAME ID VERSION NUMBER 1 octet 2 octets 1 b it 2 octets Figure 4-2: Transfer Frame Primary Header 4.1.2.2 Master Channel Identifier 4.1.2.2.1 General Bits 0–11 of the Transfer Frame Primary Header shall contain the Master Channel Identifier (MCID). The Master Channel Identifier shall consist of: a) Transfer Frame Version Number (2 bits, mandatory); b) Spacecraft Identifier (10 bits, mandatory). 4.1.2.2.2 Transfer Frame Version Number 4.1.2.2.2.1 Bits 0–1 of the Transfer Frame Primary Header shall contain the (binary encoded) Transfer Frame Version Number. 4.1.2.2.2.2 This 2-bit field shall identify the data unit as a Transfer Frame defined by this Recommendation; it shall be set to ‘00’. NOTE – This Recommendation defines the Version 1 Synchronous Transfer Frame whose binary encoded Version Number is ‘00’. 4.1.2.2.3 Spacecraft Identifier 4.1.2.2.3.1 Bits 2–11 of the Transfer Frame Primary Header shall contain the Spacecraft Identifier (SCID). 4.1.2.2.3.2 The Spacecraft Identifier shall provide the identification of the spacecraft which is associated with the data contained in the Transfer Frame. 4.1.2.2.3.3 The Spacecraft Identifier shall be static throughout all Mission Phases. CCSDS 132.0-B-1 Page 4-3 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL NOTE – The Secretariat of the CCSDS assigns Spacecraft Identifiers according to the procedures in reference [5]. 4.1.2.3 Virtual Channel Identifier Bits 1...
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This document was uploaded on 03/06/2014.

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