Comtech EF Data SDM-100A - Manual (Page 150)

Maintenance SDM-100A Satellite Modem
5–8 Rev. 0
5.2 Fault Isolation
The modem has been designed so that a competent technician can isolate fault conditions
without removing the modem from its location. The fault monitoring capability of the
modem is designed to aid the operator in determining the cause of a failure.
System faults are reported in the Faults menu, and stored faults are reported in the
StFaults menu.
Refer to Figure 5-4 for an illustration of the modem fault tree.
Refer to Section 3.2.1.3.1 for further information on each fault.
T
X
I
F
O
U
T
P
U
T
O
F
F
T
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I
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O
U
T
P
U
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F
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F
A
U
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T
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E
D
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D
R
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F
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D
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F
A
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E
D
C
O
M
E
Q
F
A
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T
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E
D
C
O
M
E
Q
F
A
U
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T
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E
D
C
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M
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Q
F
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R
E
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A
Y
C
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M
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Q
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INTERFACE FAULTS MOD FAULTS
IF SYNTHESIZER
DATA CLOCK SYN
I CHANNEL
Q CHANNEL
1 1 1
1 1 1
1
1 1 1
1 1
TX CLK ACTIVITY
BUFFER UNDERFLOW
TX INTF 1
1
1
1
RX INTF FLTS BUFFER
BUFFER CLK ACT
1
1 1 1
1 1 AGC
MODULE
DEMOD FAULTS
CARRIER DETECT 1 1
1
1
1
1
1
BATTERY/CLOCK
-12V POWER SUPPLY
+12V POWER SUPPLY
COMMON EQUIPMENT FAULTS
1
1
1 1
1
1 IF SYNTHESIZER
I CHANNEL
Q CHANNEL
DESCRAMBLER
BER THRESHOLD
MODULE
1
1
1
1
1
+5V SUPPLY
CONTROLLER
INTERFACE MODULE
1 1
1
1 1
1
Figure 5-4. Fault Tree