Operating instructions

Table of Contents DMD20/DMD20 LBST Universal Satellite Modem
viii TM103 – Rev. 2.8
3.2.4 Modem Monitor Status __________________________________________________ 3-6
3.3 Async Port / ES-ES Communications_________________________________________ 3-7
3.4 Internal Clock ___________________________________________________________ 3-7
3.5 Loopback Features (Terrestrial & IF) _________________________________________ 3-8
3.6 Clocking Options _______________________________________________________ 3-11
3.6.1 TX Clock Options _____________________________________________________ 3-11
3.6.1.1 SCTE: Serial Clock Transmit External ____________________________________ 3-12
3.6.1.2 SCT: Serial Clock Transmit ____________________________________________ 3-12
3.6.2 RX Buffer Clock Options ________________________________________________ 3-12
3.6.2.1 RX Sat Clock _______________________________________________________ 3-13
3.6.2.2 SCTE: Serial Clock Transmit External ____________________________________ 3-13
3.6.2.3 SCT: Serial Clock Transmit ____________________________________________ 3-13
3.6.2.4 EXT CLK/EXT BNC: External Clock, J16__________________________________ 3-13
3.6.2.5 EXT IDI: Insert Data In ________________________________________________ 3-13
3.6.3 EXT REF: External Reference, Top BNC Port, J10 ___________________________ 3-14
3.7 RS530/422/V.35 Interface (Standard) _______________________________________ 3-14
3.7.1 G.703 Interface (Optional)_______________________________________________ 3-14
3.7.2 HSSI Interface (Optional) _______________________________________________ 3-14
3.7.3 Ethernet Data Interface (Optional)_________________________________________ 3-14
3.8 Reed-Solomon Codec ___________________________________________________ 3-15
3.8.1 Reed-Solomon Operation in the DMD20____________________________________ 3-15
3.8.2 Reed-Solomon Code Rate ______________________________________________ 3-15
3.8.3 Interleaving __________________________________________________________ 3-15
3.9 Asynchronous Overhead Operation (Framing/Multiplexer Capability) _______________ 3-17
3.10 Standard IBS Mode ____________________________________________________ 3-19
3.11 Asynchronous Multiplexer Mode __________________________________________ 3-19
3.12 ESC Backward Alarms __________________________________________________ 3-20
3.12.1 To Disable the ESC Backward Alarms ____________________________________ 3-21
3.13 Satellite Control Channel (SCC)___________________________________________ 3-21
3.13.1 SCC Framing Structure ________________________________________________ 3-21
3.13.2 Aggregate Data Rate__________________________________________________ 3-22
3.13.3 Overhead Rate Comparison ____________________________________________ 3-23
3.13.4 Actual Overhead Rate Calculation _______________________________________ 3-23
3.13.5 SCC Overhead Channel Setup __________________________________________ 3-24
3.14 EDMAC Satellite Framing/Deframing Mode__________________________________ 3-26
3.15 Locating the ID Code Operational Procedure_________________________________ 3-26
3.16 Strap Codes __________________________________________________________ 3-26