Comtech EF Data DMDVR20 LBST Rev 1.1 - Manual (Page 12)

DMDVR20 LBST Satellite Modem Introduction
TM136 – Rev. 1.1 1-1
Introduction
1
This chapter provides an overview of the DMDVR20 LBST Satellite Modem. The DMDVR20
LBST will be referred to in this manual as “the standard unit” and the DMDVR20 LBST will be
referred to as the LBST. When describing the DMDVR20 LBST, it may be referred to as “the
DMDVR20 LBST”, “the modem”, or “the unit”.
1.0 Overview
The Radyne DMDVR20 LBST Satellite Modem (Figure 1-1) offers the best features of a
sophisticated programmable modem.
Figure 1-1. DMDVR20 LBST Satellite Modem Front Panel
This versatile equipment package combines unsurpassed performance with numerous user-
friendly Front Panel Programmable Functions. The DMDVR20 LBST provides different services
for the modulator and the demodulator. The modulator supported services are: Closed net,
Intelsat IBS and LDPC Receiver. All of the configuration and Monitor and Control (M&C)
Functions are available at the Front Panel. Operating parameters, such as variable data rates,
FEC Code Rate, modulation type, IF Frequencies, Framing and interface type can be readily set
and changed at the Front Panel by earth station operations personnel.
The modulator operates at all standard IBS Data Rates up to 8.448 Mbps. Selection of any data
rate is provided over the range of 2.4 Kbps to 20 Mbps in 1 bps steps. The Demodulator
supports LDPC Broadcast Services. The LDPC supports QPSK, 8PSK and 16APSK applications
with symbol rates of 2 to 20 Msps. Standard Interface available on the unit is RS422/530.
The DMDVR20 LBST offers additional features that serves as an interface between the indoor
unit (DMDVR20 LBST) and the outdoor units (consisting of the BUC and LNB). The output
frequency of the LBST is 950 to 2050 MHz. The LBST TX port can supply voltage, 10 MHz
Reference and FSK to the BUC via the IFL cable. The RX port can supply LNB via the IFL Cable.
The BUC voltage supplied to the BUC can either be 24 or 48 Volts. The Rx Port LNB voltage
consists of 18 volts.
The LBST has the capability to enable and disable the BUC/LNB voltages and 10 MHz reference
via the front panel. In addition, monitoring features provide verification of system status. The
LBST monitors both the current and the voltage at the output of the Tx Port, thus allowing the
user to monitor the status of both the indoor units and outdoor units.