Specifications

Table of ContentsTable of Contents Revision 14
DMD20/DMD20LBST Universal Satellite Modem MN-DMD20-20LBST
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3.3.4 Modem Monitor Status ..................................................................................................... 3–7
3.4 Async Port / ES-ES Communications.................................................................................... 3–7
3.5 Internal Clock ........................................................................................................................ 3–7
3.6 Loopback Features (Terrestrial & IF) .................................................................................. 3–8
3.7 Clocking Options ................................................................................................................. 3–11
3.7.1 TX Clock Options .......................................................................................................... 3–11
3.7.1.1 SCTE: Serial Clock Transmit External ........................................................................ 3–12
3.7.1.2 SCT: Serial Clock Transmit ........................................................................................ 3–12
3.7.2 RX Buffer Clock Options ............................................................................................... 3–12
3.7.2.1 RX SAT Clock ........................................................................................................... 3–13
3.7.2.2 CTE: Serial Clock Transmit External .......................................................................... 3–13
3.7.2.3 SCT: Serial Clock Transmit ........................................................................................ 3–13
3.7.2.4 EXT CLK/EXT BNC: External Clock, J16 ................................................................. 3–13
3.7.2.5 EXT IDI: Insert Data In .............................................................................................. 3–13
3.7.3 EXT REF: External Reference, Top BNC Port, J10 ........................................................ 3–14
3.8 RS530/422/V.35 Interface (Standard) ................................................................................. 3–14
3.8.1 G.703 Interface (Optional) .............................................................................................. 3–14
3.8.2 HSSI Interface (Optional) ............................................................................................... 3–14
3.8.3 Ethernet Data Interface (Optional) .................................................................................. 3–14
3.9 Reed-Solomon Codec ........................................................................................................... 3–15
3.9.1 Reed-Solomon Operation ............................................................................................... 3–15
3.9.2 Reed-Solomon Code Rate............................................................................................... 3–15
3.9.3 Interleaving .................................................................................................................... 3–16
3.10 Asynchronous Overhead Operation (Framing/Multiplexer Capability) ............................ 3–17
3.11 Standard IBS Mode ............................................................................................................. 3–18
3.12 Asynchronous Multiplexer Mode ....................................................................................... 3–19
3.13 ESC Backward Alarms ........................................................................................................ 3–19
3.13.1 To Disable the ESC Backward Alarms ........................................................................... 3–19
3.14 Satellite Control Channel (SCC) ......................................................................................... 3–19
3.14.1 SCC Framing Structure .................................................................................................. 3–20
3.14.2 Aggregate Data Rate ...................................................................................................... 3–21
3.14.3 Overhead Rate Comparison ............................................................................................ 3–21
3.14.4 Actual Overhead Rate Calculation .................................................................................. 3–22
3.14.5 SCC Overhead Channel Setup ........................................................................................ 3–23
3.15 DoubleTalk Carrier-in-Carrier Option ............................................................................... 3–25
3.15.1 What is DoubleTalk Carrier-in-Carrier? .......................................................................... 3–25
3.15.2 Application Requirements .............................................................................................. 3–25
3.15.3 Operational Recommendations ....................................................................................... 3–28