SDM-9000 Satellite Modem
Maintenance
Rev. 4
6–23
6.2.2.2.4 RX Interface Faults
Fault/Alarm
Possible Problem and Action
BUFFER UNDERFLOW
Buffer underflow alarm.
Indicates the plesiochronous buffer has underflowed. Buffer
underflow is normally a momentary fault (there are clock
problems if this is continuously present). This fault is included in
this section to be consistent with the fault reporting system and
correctly registered in the stored fault memory. The time and date
of the first 10 receive buffer underflow faults are stored in battery-
backed memory as an aid to troubleshooting. The interval
between stored overflow/underflow events can be used to
determine relative clock accuracies.
BUFFER OVERFLOW
Buffer overflow alarm.
Indicates the plesiochronous buffer has overflowed. The
problems and actions in the buffer underflow section apply to this
alarm.
RX DATA/AIS
Data or incoming AIS fault.
The data monitored for RX data is coming from the satellite.
When the AIS is selected for RX Data Fault in the Interface
Configuration menu, the RX data/AIS is monitoring an alarm
condition of all 1s from the satellite. When data is selected for RX
data fault in the Interface Configuration menu, the RX data/AIS is
monitoring a fault condition of all 1s or 0s. This is referred to as a
data-stable condition (meaning the data is not transitioning). The
alarm indicates trouble in receiving data from the satellite. The
indication is a monitor function only to help isolate the source of
trouble in a system.
FRAME BER
The receive decoded error rate has exceeded 1.0
-3
over a
60-second period measured on the framing bits.
This is defined as a major receive fault by INTELSAT
specifications IESS-308. In a redundant system, a switchover will
be attempted.
BUFFER CLK PLL
Buffer clock phase-locked-loop fault.
The buffer synthesizer is the wrong frequency or will not lock.
Ensure the selected buffer clock source is at the proper
frequency and level. If the fault continues, return the interface
card for repair.
BUFFER CLK ACT
Activity detector alarm of the selected interface receive clock.
The interface will fall back to the internal clock when this alarm is
active.
DEMUX_LOCK
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 fault. This fault will occur
when no carrier is present, but will probably never occur with a
correct signal.
Summary of Contents for SDM-9000
Page 2: ......
Page 5: ...8 Mbit s w IDR Figure 1 7 16QAM BER Performance Curves with Reed Solomon Filename T_ERRATA 3...
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Page 27: ...SDM 9000 Satellite Modem Introduction Rev 4 1 5 Figure 1 3 SDM 9000 Block Diagram...
Page 42: ...Introduction SDM 9000 Satellite Modem 1 20 Rev 4 This page is intentionally left blank...
Page 64: ...Configuration SDM 9000 Satellite Modem 3 6 Rev 4 JP1 Figure 3 4 Interface PCB AS 3971...
Page 65: ...SDM 9000 Satellite Modem Configuration Rev 4 3 7 Figure 3 5 Interface PCB AS 4477...
Page 66: ...Configuration SDM 9000 Satellite Modem 3 8 Rev 4 JP1 JP6 JP7 Figure 3 6 Interface PCB AS 5618...
Page 70: ...Configuration SDM 9000 Satellite Modem 3 12 Rev 4 Figure 3 7 Nyquist Filter Installation...
Page 83: ...SDM 9000 Satellite Modem Operation Rev 4 4 9 This page is intentionally left blank...
Page 87: ...SDM 9000 Satellite Modem Operation Rev 4 4 13 This page is intentionally left blank...
Page 104: ...SDM 9000 Satellite Modem Operation Rev 4 4 31 This page is intentionally left blank...
Page 107: ...Operation SDM 9000 Satellite Modem 4 34 Rev 4 This page is intentionally left blank...
Page 124: ...SDM 9000 Satellite Modem Operation Rev 4 4 51 Figure 4 17 RF Loopback Figure 4 18 IF Loopback...
Page 150: ...Theory of Operation SDM 9000 Satellite Modem 5 22 Rev 4 Figure 5 6 Interface Block Diagram...
Page 158: ...Theory of Operation SDM 9000 Satellite Modem 5 30 Rev 4 This page is intentionally left blank...
Page 186: ...Maintenance SDM 9000 Satellite Modem 6 28 Rev 4 This page is intentionally left blank...
Page 218: ...Options SDM 9000 Satellite Modem A 32 Rev 4 This page is intentionally left blank...
Page 242: ...Remote Control Operation SDM 9000 Satellite Modem B 24 Rev 4 ref SE_ command...
Page 254: ...Glossary SDM 9000 Satellite Modem g 6 Rev 4 This page is intentionally left blank...
Page 256: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX...