3252 although the transfer of ocfsdus is synchronized

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Unformatted text preview: sfer of OCF_SDUs is synchronized with the Virtual Channel or Master Channel that shall provide the transfer service, the creation of OCF_SDUs by the CCSDS 132.0-B-1 Page 3-2 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL sending user may or may not be synchronized with the Virtual Channel or Master Channel. Such synchronization, if required for timing or other purposes, is a mission-design issue. NOTE – Operational Control Field Service Data Units (OCF_SDUs) are fixed-length data units, each consisting of four octets, carried in the Operational Control Field (OCF), defined in 4.1.5, from a sending end to a receiving end. As defined in 4.1.5, CCSDS specifies the use of the first bit of this field to indicate the type of data carried. 3.2.6 TM TRANSFER FRAME Transfer Frames transferred by the Virtual Channel Frame and Master Channel Frame Services shall be partially formatted TM Transfer Frames, and the following restrictions apply: a) the Master Channel Frame Count Field of the Transfer Frames submitted to the Virtual Channel Frame Service shall be empty; b) if the MC_FSH Service exists on a Master Channel, the Transfer Frame Secondary Header and the Transfer Frame Secondary Header Flag of the Transfer Frames submitted to the Virtual Channel Frame Service on the same Master Channel shall be empty; c) if the MC_OCF Service exists on a Master Channel, the Operational Control Field and the Operational Control Field Flag of the Transfer Frames submitted to the Virtual Channel Frame Service on the same Master Channel shall be empty; d) the Frame Error Control Field of the Transfer Frames submitted to the Master or Virtual Channel Frame Service shall be empty, if it is present on the Physical Channel. NOTE – The TM Transfer Frame is the fixed-length protocol data unit of the TM Space Data Link Protocol, but also can be used as the service data units of the Virtual Channel Frame and Master Channel Frame Services. Its format is defined in 4.1 of this Recommendation....
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This document was uploaded on 03/06/2014.

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