132x0b1c1

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Unformatted text preview: ; b) the Type Flag shall be ‘1’ if the Operational Control Field holds a Type-2-Report. NOTE – The Type Flag may vary between Transfer Frames on the same Master or Virtual Channel that carries this field. 4.1.5.5 The first bit of a Type-2-Report (i.e., bit 1 of the Operational Control Field) shall indicate the use of this report as follows: a) if this bit is ‘0’, the contents of the report are project-specific; b) if this bit is ‘1’, the contents of the report are reserved by CCSDS for future application. NOTES 1 The value of the first bit of a Type-2-Report may vary between Transfer Frames on the same Master or Virtual Channel that carries this field. 2 The purpose of this field is to provide a standardized mechanism for reporting a small number of real-time functions (such as retransmission control or spacecraft clock calibration); currently the use for retransmission control (Type-1-Reports) has been defined by CCSDS in reference [B6]. This issue of the Recommendation does not define the use of Type-2-Reports; however, it reserves the possibility to do so in future issues by restricting the utilization of the first bit. 4.1.6 FRAME ERROR CONTROL FIELD 4.1.6.1 General 4.1.6.1.1 If present, the Frame Error Control Field shall occupy the two octets following, without gap, the Operational Control Field if this is present, or the Transfer Frame Data Field, if an Operational Control Field is not present. CCSDS 132.0-B-1 Page 4-12 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL 4.1.6.1.2 The Frame Error Control Field is optional; its presence or absence shall be established by management. 4.1.6.1.3 If present, the Frame Error Control Field shall occur within every Transfer Frame transmitted within the same Physical Channel throughout a Mission Phase. NOTES 1 The purpose of this field is to provide a capability for detecting errors which may have been introduced into the Transfer Frame during the transmission and data handling process. 2 Whether this field should be used on a particular Phy...
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This document was uploaded on 03/06/2014.

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