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Unformatted text preview: e encoding process; they
are not removed by the decoding process. Removal of fill is the responsibility of the layer
above, which delimits the end of the Input Data and discards extraneous bits (e.g., fill).
NOTE – If randomization is being used, any fill octets that were added to the last
codeblock of the CLTU will be derandomized even if they were not randomized. CCSDS 201.0-B-3 Page 3-5 June 2000 CCSDS RECOMMENDATION FOR TELECOMMAND: CHANNEL SERVICE 3.3.4 TC CHANNEL SERVICE LOGIC The TC Channel Service Logic at the receiving end is presented in state diagram form
(Figure 3-5). To support the state diagrams, a list of “states” and “events” is given in Tables
3-1 and 3-2. There are three states and four events.
Table 3-1: TC Channel Service States (Receiving End)
Definition S1 INACTIVE The telecommand channel is INACTIVE (i.e.,
“no bit lock is achieved”, or, alternatively,
“no bit modulation is detected”. S2 SEARCH The incoming bit stream is searched, bit by
bit, for the Start Sequence pattern. S3 DECODE TC Codeblocks, which are either free of
error or which can be corrected, are
received, decoded, and dera...
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- Spring '14