Modulator Checkout; Initial Power-Up - Radyne DMD20 Installation And Operation Manual

Installation
Demodulator:
Data Rate:
Mode:
Satellite Framing:
Scrambler:
Drop and Insert:
Inner FEC:
Outer FEC:
Modulation:
Frequency:
To lock up the modem, enter 'IF Loopback Enable' under the Test Menu, or connect a Loopback
Cable from J1 to J2 on the rear panel of the modem.

2.5 Modulator Checkout

The following descriptions assume that the DMD20 is installed in a suitable location with prime
AC power and supporting equipment available.

2.5.1 Initial Power-Up

Before initial power up of the DMD20, it is a good idea to disconnect the
transmit output from the operating ground station equipment. This is
especially true if the current Modulator Configuration Settings are
unknown, where
communications traffic. New units from the factory are normally shipped
in a default configuration which includes setting the transmit carrier off.
Turn on the unit by placing the Rear Panel Switch (loc ated above the power entry connector) to
the On Position. Upon initial and subsequent power-ups, the DMD20 Microprocessor will test
itself and several of its components before beginning its Main Monitor/Control Program. These
power-up diagnostics show no results if successful. If a failure is detected, the Fault LED will
illuminate.
The initial field checkout of the modem can be accomplished from the Front Panel or in the
Terminal Mode. The Terminal Mode has the advantage of providing full screen access to all of
the modem's parameters, but requires a separate terminal or computer running a Terminal
Program. The unit is placed into terminal mode by setting two options via the Front Panel. The
two options are the Term Baud and Emulation settings found under the System M&C Submenus.
2-4
2.048 Mbps
Closed Network
None
V.35 (IESS)
Disabled
1/2 Rate Viterbi
Disabled
QPSK
70.000000 MHz
incorrect settings
DMD20 Universal Satellite Modem
could disrupt the existing
TM103 - Rev. 1.1