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SDM-309B Satellite Modem
FRM_BER
BW_ALARM
Insert
Ins_Clk
RX_PLL
BUFF_CLK
MUX_LOCK
104.5
109.5
114.5
119.5
124.5
129.5
134.5
139.5
MN/U-SDM309B Rev. #
Frame Bit Error Rate.
The receive decoded error rate has exceeded 10E-3 over a 60 second
period, measured on the framing bits. This is defined as a major (prompt)
receive alarm by Intelsat Specification IESS-308. In a redundant system a
switchover will be attempted. Since some data must be correctly received
to indicate this fault, receive AIS will not be substituted. This fault is to be
sent as a backward alarm to the distant end. This must be wired externally
as faults other than from the modem may need to enter the fault tree.
Backward Alarm Fault.
Modem is receiving a backward alarm indicating trouble at the distant end
which may be a result of improper transmission at the near end of the link.
This particular alarm is reported and recorded but the modem takes no
other action. In most cases however, this fault is due to some receive
problem with the modem so a "real" fault will probably be occurring if
backward alarm faults are being recorded.
(D&I Only) Insert Interface Hardware Fault.
The typical cause of this fault is the insert phase locked loop is not locked
or some other insert interface hardware has malfunctioned. Return the
Drop and insert channel unit to the factory for repair.
(D&I Only) Insert Clock Fault.
This fault occurs when no data is present on the Terrestrial side of the
interface usually caused by the wrong clock selection such as the insert
clock source is selected as "External" and no external clock is present.
Check the selected clock source and verify the clock is present. If the fault
is modem related, other faults will also occur. If the Satellite clock is
selected a demod fault, "Data Clk_Syn" fault will probably occur. If the
Insert clock is selected a mod fault, "TX_Clk_Syn" fault will probably occur.
(IBS/M1200P Only) Indicates a loss of lock on the reference of the
interface receive clock recovery oscillator. Return the interface card for
repair.
Loss of activity on the selected buffer clock source. The modem will
fallback to the satellite clock.
Demultiplexer Synchronization Lock Fault This fault means that the
demultiplexer is unable to maintain valid frame and multiframe alignment.
The usual cause is invalid or absent receive data. This is a major (prompt)
alarm. It will cause insertion of receive Alarm Indication Signal (all ones)
and switchover will be attempted. This fault is to be sent as a backward
alarm to the distant end. This fault will occur when no carrier is present,
but will probably never occur with a correct signal.
Programmable Data Rates For The EFData
64.0
64.5
65.0
65.5
69.5
70.0
70.5
74.5
75.0
75.5
79.5
80.0
80.5
84.5
85.0
85.5
89.5
90.0
90.5
94.5
95.0
95.5
99.5
100.0
100.5
105.0
105.5
110.0
110.5
115.0
115.5
120.0
120.5
125.0
125.5
130.0
130.5
135.0
135.5
140.0
140.5
Table 6-2
Variable Rate SDM-309B Modem
66.0
66.5
67.0
71.0
71.5
72.0
76.0
76.5
77.0
81.0
81.5
82.0
86.0
86.5
87.0
91.0
91.5
92.0
96.0
96.5
97.0
101.0
101.5
102.0
106.0
106.5
107.0
111.0
111.5
112.0
116.0
116.5
117.0
121.0
121.5
122.0
126.0
126.5
127.0
131.0
131.5
132.0
136.0
136.5
137.0
141.0
141.5
142.0
Maintenance
67.5
68.0
68.5
72.5
73.0
73.5
77.5
78.0
78.5
82.5
83.0
83.5
87.5
88.0
88.5
92.5
93.0
93.5
97.5
98.0
98.5
102.5
103.0
103.5
107.5
108.0
108.5
112.5
113.0
113.5
117.5
118.0
118.5
122.5
123.0
123.5
127.5
128.0
128.5
132.5
133.0
133.5
137.5
138.0
138.5
142.5
143.0
143.5
69.0
74.0
79.0
84.0
89.0
94.0
99.0
104.0
109.0
114.0
119.0
124.0
129.0
134.0
139.0
144.0
6-6–17
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