Table of Contents
Advertisement
SDM-2020 Satellite Demodulator
3.2.1
LED Indicators
The seven LEDs on the front panel indicate:
•
•
•
Refer to Table 3-2 for indicator descriptions.
Name
Receive
Receive
Stored
Power On
Sync
Carrier Detect
Test Mode
At system level, a fault simultaneously activates the demodulator fault relay, DF, a
TTL-OC fault indication, and turns on the red Receive Fault LED. This condition is used
by redundancy switches to cause a switch-over to replace a failed unit. Refer to Chapter
1, Fault Tree.
An alarm condition turns on the yellow Receive Alarm LED and activates the
demodulator alarm relay. Alarms do not activate the fault indications described above.
For Single L-Band Input Connector Units - There is a status LED visible from the rear
panel of the demodulator.
Refer to Table 3-3.
Name
LNB Power
Note: Units with four L-Band input connectors have no LED indicator.
Rev. 3
Alarms
Summary fault information
General demodulator status
Table 3-2. LED Indicator Description, Front Panel
LED
Yellow
A receive function is in an alarm condition.
Red
A fault condition exists in the receive chain.
Yellow
A fault has been logged and stored.
The fault may or may not be active.
Green
Power is applied to the demodulator.
Green
The demodulator is synchronized to the data.
Green
Viterbi/TCM decoder is locked.
Yellow
Flashes when the demodulator is in a test configuration.
The test mode status can be identified in the utility system
menu in Figure 3-13.
Table 3-3. Rear Panel LED Indicator Description
LED
Green
The LNB power is ON, when the LED is illuminated.
Description
Alarms
Faults
Status
Description
Operation
3–3
Advertisement
Table of Contents
