Table of Contents
Advertisement
Quantum and Evolution Series Installation and Operating Handbook
Fault Text
A backward alarm has been detected at the Rx input.
This indicates that equipment downstream of the transmit
Rx warning: Backward
path (i.e. from the modem Tx output) has failed and is
alarm from satellite
returning an alarm. This may be due to a downstream
detected at Rx input,
receive path equipment failure, the modem Tx failing or a
indicating Tx or
satellite failure. Check the modem Tx path status. Check
downstream of Tx
the Tx IF output from the modem is connected to the
equipment fault.
upconverter equipment and onwards. Monitor the Tx
carrier (or distant Rx if possible) with a spectrum
analyser.
A multiframe backward alarm has been detected at the
Rx warning: CAS
Rx input indicating that equipment downstream of the
multiframe backward alarm
transmit path has failed to synchronise to the CAS
from satellite, indicating
multiframe and is returning an alarm. This could be
equipment downstream of
caused by any equipment from the Tx modulator
Tx has failed to find CAS
onwards but is unlikely to be other than the Tx mod, the
MF sync.
Rx demod, or further down the Rx path.
This indicates which of the four backward alarms are
active at the Rx input. This indicates that equipment
downstream of the transmit path (ie the distant end Rx
path or further downstream) has failed and is returning
Rx warning: Backward
an alarm. In Multidestinational circuits this may not
alarm 1 (or 2 or 3 or 4)
correspond to the Tx path of this modem. The fault may
from satellite, indicating
be due to any receive downstream equipment, but could
equipment downstream of
be due to the relevant modem Tx output failing. Check
Tx has failed.
the relevant modem Tx path indicates OK. Check the Tx
IF output from the modem is connected to the
upconverter equipment and onwards and monitor the Tx
carrier (or distant Rx if possible) with a spectrum
analyser.
This will only be displayed if the modem if fitted with an
interface that provides four ports for separate input and
output of separate Tx/Drop and Rx/Insert PCM bearers. It
Rx warning: Backward
indicates a backward alarm has been detected at the Rx
alarm at Insert MUX,
bearer input. This indicates that equipment downstream
indicating equipment
of the receive path has failed and is returning an alarm.
downstream of Rx has
This may be due to any receive downstream equipment,
failed.
but could be due to the modem Rx output failing. Check
the modem Rx path indicates OK and that the Rx data
output from the modem is connected to the downstream
equipment.
Rx warning: The final BER
is worse than the user
threshold set for the
deferred alarm.
Notes
12-6
Relays To Ter To Sat
Other
D
TB
D
TE
D
D
D
Advertisement
Table of Contents
