StarGuide Digital Networks StarGuide III, Руководство пользователя

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SGN 71001-1017
11
4 F
R ON T
P
AN E L
O
P E R AT I ON S
The Front Panel is used to control the basic functions of the StarGuide III Receiver. It consists
of a 2-line by 16-character LCD window, a keypad, and a row of five status LED’s. The LCD
window is used to display the current receiver status or the current menu option. The keypad is
used to navigate through the Front Panel menus and to enter specific parameters. The five status
LED’s give a quick indication of the current status of the receiver. Figure 2 illustrates the
StarGuide III front panel.
Keypad for control
and data entry
SIGNAL LED to
indicate the
presence of the
satellite signal
SYNC LED to
indicate if the
receiver is
synchronized
STANDBY LED
to indicate
software
download status
FAULT LED to
indicate that
something is
wrong
16 x 2 LCD for
menu and status
display
POWER LED to
indicate the unit
is on.
Figure 2. Front Panel Features
4.1 The Status LED’s
There are five LED’s on the StarGuide front panel. The following sections describe each LED
and its significance.
4.1.1 The SIGNAL LED
The SIGNAL LED is used to indicate when the receiver has found the signal and determined its
relative strength. When the receiver finds the satellite signal this LED will turn ON. If the signal
strength drops below 5.0 dB E
b
/N
0
(energy per information bit) the SIGNAL LED will begin to
flicker. As the signal continues to drop the LED will continue to blink, however it will be OFF
most of the time until the E
b
/N
0
drops to 3.5 dB. Once the signal level drops below 3.5 dB the
SIGNAL LED will remain OFF.
4.1.2 The SYNC LED
The SYNC LED indicates that the receiver has acquired the signal and obtained
synchronization. This LED should be ON during normal operation.