Q-Lite Satellite Modem Installation and Operating Handbook
11-5
11.3 Receive Faults
Fault Text
Notes
Relays To Ter To Sat Other
Rx fault: RS de-interleaver
unable to sync to decoded
data. Check RS settings.
The demodulator can lock to the carrier and the inner
FEC decoder to the demodulated data. However, the
Reed-Solomon de-interleaver cannot synchronise with
the decoded data. Check the RS de-interleaving depth
and the values of `n` and `k`.
R
TA,TC SB
RF
Rx fault: Demodulator
unlocked. Check modem
settings.
The demodulator cannot find a carrier to lock to at the
specified frequency. Check the frequency, data rate and
FEC settings. Check the demodulator by enabling IF
loopback test mode.
R
TA,TC SB
RF
Rx fault: Cannot find frame
sync on Rx data - check
Rx Service settings.
The modem cannot find the IBS or IDR frame sync on
the receive data. Check the Rx Service settings.
R
TA,TC SB
RF
Rx fault: Cannot find IBS
TS32 multiframe sync on
Rx data.
The modem cannot find the IBS TS32 multiframe sync on
the receive data although it has found frame sync.
R
TA,TC SB
RF
Rx fault: No insert bearer,
generating.
Modem is set to loop bearer but no bearer was detected
at Tx input. The bearer is currently being generated by
the insert mux.
R
Rx fault: CAS multiframe
sync lost.
The modem cannot find the IBS CAS multiframe sync on
the receive data although it has found frame sync and
TS32 multiframe sync. CAS Multiframe sync is used to
convey either 1) Channel Associated Signalling (CAS) in
G.732 Drop/Insert modes using CAS; 2) To maintain the
identity of a group of timeslots in some cases; 3) To
maintain Robbed Bit Signalling (RBS) in T1-D4 or T1-
ESC Drop/Insert modes. Check as follows for each use:
1) The Tx modem is set to operate in CAS mode if CAS
signalling is to be conveyed within the IBS/SMS
overhead; 2) If the Tx modem cannot use a CAS
Multiframe to maintain the TS identity for the `Odd values
of N` then to prevent this modem seeking a CAS
multiframe for one of these values, set timeslot identity to
‘Do not maintain’; 3) If the Tx modem cannot use a CAS
Multiframe to maintain RBS over satellite, switch RBS off.
R
TA,TC SB
RF
Rx fault: Final BER > 1E-3.
Final BER has exceed 1x10-3
R
TA,TC SB
Rx fault: FEC Decoder
synchronization lost.
Synchronisation has been lost in the FEC decoder.
Check inner FEC configuration.
R
TA,TC SB
RF
Rx fault: Insert data is all
ones (AIS), indicating
upstream equipment fault.
The final customer data after demodulation, error
correction, deframing and descrambling is all ones.
This is normally used to indicate an upstream equipment
fault (such as a lack of input clock at the Tx
end), it is not a modem fault.
R
TA
SB
Rx fault: Data input is all
ones (AIS), indicating
upstream equipment fault.
The modem is set to loop bearer, but that bearer is
indicating AIS.
R
Rx fault: Rx channel DPLL
unlocked.
Consult technical support if this alarm cannot be cleared.
D
Rx fault: Rx terrestrial
DPLL unlocked.
Consult technical support if this alarm cannot be cleared.
D
Rx fault: Insert mux fault
on ports (1 to 4).
Quad E1 card fault.
Rx fault: Rx SM sync loss.
Quad E1 sync loss fault.
Rx fault: Physical layer
sync lost.
DVB-S2 demodulator cannot detect valid DVB-S2
satellite frames (no data detected).
Rx fault: PCMA unlocked.
Consult troubleshooting section of Paired Carrier quick
start guide for list of potential causes.
Rx fault:
No GPS data,
check connection.
GPS input to Paired Carrier (for calculating the delay to
satellite) has failed. Check status of, and cable to, the
external GPS system.
