SDM-300A Satellite Modem
Maintenance
Rev. 4
5–19
5.2.3.6 Backward
Alarms
Faults
Fault/Alarm
Possible Problem and Action
BW ALARM RX4
Receive backward alarm #4. The distant end of the link is sending
backward alarm #4. This indicates trouble at the distant end, which may be
a result of improper transmission at the near end of the link. The modem
will signal this event by setting the deferred maintenance alarm (open
collector). This alarm is a monitor function. The modem reports and
records the event, but takes no other action. Refer to Chapter 2 for the
backward alarm theory of operation. If the user does not wish to monitor
the backward alarm faults, the backward alarm inputs must be grounded at
the breakout panel. Refer to Chapter 2 for breakout panel pinouts.
BW ALARM RX3
Receive backward alarm #3. Refer to BW Alarm RX4 for details.
BW ALARM RX2
Receive backward alarm #2. Refer to BW Alarm RX4 for details.
BW ALARM RX1
Receive backward alarm #1. Refer to BW Alarm RX4 for details.
BW ALARM TX4
Transmit backward alarm #4. The modem is being instructed to send
backward alarm #4 to the distant end of the link. This alarm is controlled
by wiring the backward alarm inputs of the modem to the demod fault
relay and/or other fault outputs in the receive system (see IESS-308 for
clarification). The simplest implementation for single destination service is
to wire the demod fault relay between ground and the four backward alarm
inputs (see Chapter 3 for clarification). This sends all four backward
alarms in the event of any major (prompt) receive fault. This particular
alarm is transmitted, reported, and recorded, but the modem takes no other
action. In most cases, this will be sent due to some receive problem with
the modem, so a real fault will probably be occurring if backward alarms
are being sent. The transmit backward alarms are a symptom of trouble,
not a cause.
BW ALARM TX3
Transmit backward alarm #3. Refer to BW Alarm TX4 for details.
BW ALARM TX2
Transmit backward alarm #2. Refer to BW Alarm TX4 for details.
BW ALARM TX1
Transmit backward alarm #1. Refer to BW Alarm TX4 for details.
Содержание SDM-300A
Страница 1: ...Part Number MN SDM300A IOM Revision 4 SDM 300A Satellite Modem Installation and Operation Manual...
Страница 33: ...Introduction SDM 300A Satellite Modem 1 14 Rev 4 This page is intentionally left blank...
Страница 36: ...SDM 300A Satellite Modem Installation Rev 4 2 3 Figure 2 1 Installation of the Mounting Bracket...
Страница 57: ...Operation SDM 300A Satellite Modem 3 4 Rev 4 This page is intentionally left blank...
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Страница 169: ...Theory of Operation SDM 300A Satellite Modem 4 18 Rev 4 This page is intentionally left blank...
Страница 176: ...SDM 300A Satellite Modem Maintenance Rev 4 5 7 WITH NOISE WITHOUT NOISE Figure 5 4 Typical Eye Constellations...
Страница 189: ...Maintenance SDM 300A Satellite Modem 5 20 Rev 4 This page is intentionally left blank...
Страница 200: ...SDM 300A Satellite Modem Options Rev 4 A 11 Figure A 2 D I with Asynchronous Overhead Data Flow...
Страница 205: ...Options SDM 300A Satellite Modem A 16 Rev 4 Figure A 3 E1 Framing Formats...
Страница 206: ...SDM 300A Satellite Modem Options Rev 4 A 17 Figure A 4 T1 Framing Formats...
Страница 237: ...Options SDM 300A Satellite Modem A 48 Rev 4 Figure A 10 IDR Interface Block Diagram...
Страница 241: ...Options SDM 300A Satellite Modem A 52 Rev 4 Figure A 11 IBS Interface Block Diagram...
Страница 257: ...Options SDM 300A Satellite Modem A 68 Rev 4 CBA Figure A 19 Reed Solomon Codec Installation...
Страница 260: ...SDM 300A Satellite Modem Options Rev 4 A 71 CBA Figure A 20 Overhead Interface PCB Installation...
Страница 265: ...Options SDM 300A Satellite Modem A 76 Rev 4 Figure A 24 8 Channel Multiplexer Installation...
Страница 273: ...Options SDM 300A Satellite Modem A 84 Rev 4 Figure A 26 Flex Mux Multiplexer Installation...
Страница 275: ...Options SDM 300A Satellite Modem A 86 Rev 4 This page is intentionally left blank...
Страница 330: ...SDM 300A Satellite Modem Remote Control Operation Rev 4 B 55...
Страница 362: ...Specifications SDM 300A Satellite Modem C 32 Rev 4 Figure C 7 8PSK BER Specification Curves 1544 kbit s...
Страница 366: ...Specifications SDM 300A Satellite Modem C 36 Rev 4 1 1 Rate Specification Figure C 9 Uncoded 1 1 BPSK QPSK and OQPSK...
Страница 388: ...Specifications SDM 300A Satellite Modem C 58 Rev 4 This page is intentionally left blank...
Страница 392: ...Glossary SDM 300A Satellite Modem g 4 Rev 4 This page is intentionally left blank...
Страница 398: ...Index SDM 300A Satellite Modem i 6 Rev 4 This page is intentionally left blank...