Comtech EF Data CDM-550T - Manual (Page 26)

CDM-550T Satellite Modem Revision 3
Installation MN/CDM550T.IOM
2–2
2.3 Configuration
There are no internal jumpers to configure, no interface cards to install, and no other options to
install. All configuration is carried out entirely in software. The unit should first be configured
locally, using the front panel keypad and display. The unit will ship with a default 64 kbps,
QPSK, Rate 1/2 configuration. Refer to the ‘FRONT PANEL OPERATION’ section for details
on how to fully configure the unit for the desired operating parameters.
The auto-sensing AC power supply does not require any adjustments. Simply plug in the supplied
line cord, and turn on the switch on the rear panel.
2.4 Select Internal IF Loop
Correct operation of the unit may be verified rapidly, without the need for externally connected
equipment. From the top level menu, select TEST, then IF LOOP (refer to the ‘FRONT
PANEL OPERATION’ section). The demod should synchronize, and the GREEN RECEIVE
TRAFFIC LED should illuminate. If the unit does not pass this test, call the factory for
assistance.
2.5 Connect External Cables
Having verified correct operation in IF loop, enter the desired configuration, and proceed to
connect all external cables. If difficulties occur, please call the factory for assistance.
Please note that the modulator gives an output power level in the range 0 to -20 dBm, and the
demodulator expects to see a signal in the range -30 to -60 dBm.
FREQUENTLY ASKED QUESTION - Optimum input level:
Adjust the input level to the demodulator so that the AGC value
displayed on the RX PARAMETERS screen reads between 90
and 95.