Comtech EF Data SDM-300A, Installation And Operation Manual

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SDM-300A Satellite Modem Operation
Rev. 4 3–83
3.4.2.7 SDM-100 Emulation Operation
The SDM-100 Emulation feature of the modem provides remote protocol compatibility
with existing SDM-100 modems, which makes several applications possible:
•
Add an SDM-300A to a rack of SDM-100s with a protection switch.
•
Replace an SDM-100 requiring service with SDM-300A.
•
Use SDM-300A as the backup modem for a rack containing a mix of SDM-100
and SDM-300A modems.
SDM-100 Emulation is typically a closed network application, with no added overhead.
The modem does not required any additional hardware to operate in SDM-100
Emulation. The basic modem configuration, which includes the 25-pin D Data I/O
connector, supports V.35, EIA-422, and EIA-232-C data.
Refer to Table 3-10 for SDM-100 emulation parameter settings.
Table 3-10. SDM-100 Emulation Parameter Settings
Parameter Front Panel Settings Reference Menu
Modem Emulation SDM-100 Utility Modem Type
TX Data/Code Rate TX-V, QPSK 1/2 Configuration Modulator
TX-IF Output ON Configuration Modulator
RX Data/Code Rate RX-V, QPSK 1/2 Configuration Demodulator
TX Clock Source TX Terrestrial Configuration Interface
Buffer Clock Source Satellite Clock Configuration Interface
Modulator Type INTELSAT Open, CSC Closed, FDC
Closed, EFD Closed Utility Modulator
Encoder Type Viterbi or Sequential Utility Modulator
Demodulator Type INTELSAT Open, CSC Closed, FDC
Closed, EFD Closed Utility Demodulator
Decoder Type Viterbi or Sequential Utility Demodulator
TX Overhead Type None Utility Interface
RX Overhead Type None Utility Interface
Interface Type EIA422, EIA232, V.35 Utility Interface
Buffer Program Bits or Milliseconds Utility Interface
RTS TX-IF Cntrl OFF or ON Utility Interface
Note: Refer to Appendix A for more information on the asynchronous interface with AUPC.