beautypg.com

2 description – Comtech EF Data SDM-9000 User Manual

Page 26

background image

Introduction

SDM-9000 Satellite Modem

1–4

Rev. 4

1.1.2 Description

The modem is a complete, self-contained unit in a standard 2 unit (2U) 19”
rack-mountable enclosure weighing approximately 19 lbs. The unit is of modular
construction consisting of five PCB assemblies:

Modulator

Demodulator

Interface

Display/Monitor & Control (M&C) (front panel)

Backplane (rear panel)

The backplane PCB is mounted on the chassis assembly and contains receptacles for
three plug-in PCBs:

Modulator

Demodulator

Interface

Test points are located on the front edges of the three PCBs. Figure 1-2 shows the front
view of the modem (without the front panel).

All M&C functions and indicators for operation of the modem are located on the
display/M&C. The chassis also contains a fan (on the rear panel) and a power supply.
Refer to Figure 1-3 for a system block diagram.

Figure 1-2. Modular Construction