Table of ContentsTable of Contents
Revision 14
DMD20/DMD20LBST Universal Satellite Modem
MN-DMD20-20LBST
iv
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