Comtech EF Data CDM-550T, Manual

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CDM-550T Satellite Modem Preface
Rev.1.3 v
7.1 Introduction ................................................................................................................................................7–1
7.2 Viterbi..........................................................................................................................................................7–1
7.3 Sequential ....................................................................................................................................................7–2
7.4 Reed-Solomon Outer Codec (Option) .......................................................................................................7–3
7.5 Turbo Product Codec (Option) .................................................................................................................7–4
7.1.1 End-to-End Processing Delay ..............................................................................................................7–6
7.6 Uncoded Operation (No FEC) ...................................................................................................................7–7
CHAPTER 8. OFFSET QPSK OPERATION .............................................................. 8–1
CHAPTER 9. EIA-232 DATA INTERFACE - ASYNCHRONOUS OPERATION ........ 9–1
9.1 Introduction ................................................................................................................................................9–1
9.2 ASYNC EIA-232 Specifications.................................................................................................................9–1
9.3 Setup ............................................................................................................................................................9–2
9.4 Other Considerations .................................................................................................................................9–2
9.4.1 Baud Rate Accuracy ............................................................................................................................9–2
9.4.2 Async Character Formats Using 1.5 Stop Bits.....................................................................................9–2
CHAPTER 10. CLOCKING....................................................................................... 10–1
10.1 Transmit Clocking ...............................................................................................................................10–1
10.1.1 Internal Clock ................................................................................................................................10–1
10.1.2 External Clock ...............................................................................................................................10–1
10.1.3 Loop-Timed, RX=TX....................................................................................................................10–2
10.1.4 Loop-Timed, RX<>TX (Asymmetric Loop Timing) ....................................................................10–2
10.2 Receive Clocking ..................................................................................................................................10–2
10.2.1 Buffer Disabled .............................................................................................................................10–2
10.2.2 Buffer Enabled, RX=TX ...............................................................................................................10–2
10.2.3 Buffer Enabled, RX<>TX .............................................................................................................10–3
10.3 X.21 Notes .............................................................................................................................................10–3
10.4 Loop Timing With Sync EIA-232 .......................................................................................................10–3
CHAPTER 11. EDMAC CHANNEL .......................................................................... 11–1
11.1 Theory Of Operation ...........................................................................................................................11–1
11.2 M&C Connection .................................................................................................................................11–2
11.3 Setup Summary ....................................................................................................................................11–3