ViaSat VBM-1400, Инструкция по установке и эксплуатации

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VBM-1400 Broadband Modulator Installation and User’s Guide
General Theory of Operation
Rev. 002 1018360
5-1
5. General Theory of Operation
This section contains a basic block diagram description of the VBM-
1400. Each functional area is described below. See Figure 5-1
throughout the discussion.
Figure 5-1 VBM-1400 Basic Block Diagram
5.1 Power Distribution
The Power Supply supplies the DC voltages to the internal components
using 100-240 VAC, 50-60 Hz, at a maximum of 0.5 amperes. An
on/off switch on the rear panel controls the application of AC to the
power supply.
5.2 Monitor and Control
The Monitor and Control (M&C) module is microprocessor based and
provides the ability to set system parameters remotely using EIA-485,
EIA-232, Ethernet, or locally using the Front Panel. The circuits
perform modulator closed loop power control, factory power calibration,
and periodically poll the circuits for status of key monitor points as
follows:
M & C Module
RF Board*
*70,140 MHz or
L-Band
(950 -1450
MHz)
Freq/Clock
Generation
FEC
FPGA
MOD
FPGA
DAC
I +
I -
Q +
Q -
TX OUT
REMOTE
ETHERNET
Baseband Interface Board
Modulator
Board
Power Supply
Internal DC
Voltages
TX MON
(-20 dBm)
ASI IN
DVB/M2P
IN
ALARM
DAC
CTL
REF IN
REF OUT
Front Panel
CTL
M&C
FPGA
DRIVERS
AFMC CTL DATA
CT
L