Notes 1 oid transfer frames are sent to maintain

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Unformatted text preview: Packet to send. 2 OID Transfer Frames may be sent on Virtual Channels that also carry valid Packets, but it is preferred that a separate Virtual Channel be dedicated to carry Idle Transfer Frames unless there is a need to send Idle Transfer Frames on a specific Virtual Channel (e.g., to transmit data in the Transfer Frame Secondary Header and/or the Operational Control Field on a specific Virtual Channel). 3 An OID Transfer Frame can be generated whenever it is necessary (even in the middle of transmission of a Packet that is split into multiple Transfer Frames). 4 OID Data in the Transfer Frame Data Field of an OID Transfer Frame should not be confused with the Idle Packet specified in reference [6]. 4.1.5 OPERATIONAL CONTROL FIELD 4.1.5.1 If present, the Operational Control Field shall occupy the four octets following, without gap, the Transfer Frame Data Field. NOTE – The Operational Control Field is optional; its presence or absence is signaled by the Operational Control Field Flag in the Transfer Frame Primary Header (see 4.1.2.4). 4.1.5.2 If present, the Operational Control Field shall be associated with either a Master Channel or a Virtual Channel. CCSDS 132.0-B-1 Page 4-11 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL NOTE – The association of an Operational Control Field with a Master Channel allows data to be transferred synchronized with this Master Channel. The association of an Operational Control Field with a Virtual Channel allows data to be transferred synchronized with this Virtual Channel. 4.1.5.3 If present, this field shall occur within every Transfer Frame transmitted through the associated Master or Virtual Channel throughout a Mission Phase. 4.1.5.4 The leading bit of the field, i.e., bit 0, shall contain a Type Flag with the following meanings: a) the Type Flag shall be ‘0’ if the Operational Control Field holds a Type-1-Report which shall contain a Communications Link Control Word, the content of which is defined in reference [B6]...
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This document was uploaded on 03/06/2014.

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