Comtech EF Data CDM-550T, Manual

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Rev. 1.3 1–1
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Chapter 1.
INTRODUCTION
The CDM-550T (Figure 1-1) is a very low-cost Closed Network Satellite Modem,
intended for both VSAT and hub applications. It offers variable data rates from 2.4 to
2048kbps, in BPSK, QPSK and Offset QPSK modes. Both Viterbi and Sequential
Forward Error Correction (FEC) are provided as standard.
Figure 1-1. CDM-550T
The modem is compact, 1U high and 12 inches deep, and consumes only 18 watts. It has
a front panel VFD display and keypad for local configuration and control, although it can
be fully remote-controlled.
1.1 Standard Features
IF port impedance is selectable from the front panel. Users may choose between the
universal standard of 50 ohms or the less frequently used 75 ohms. The CDM-550T
offers both impedances in the same unit as a standard feature.