Paradise Datacom P300-VSAT Installation & Operating Handbook page 207

Text on Display
Tx Warn: Framer Sig' FIFO slip
Tx Warn: RS Encoder FIFO slip
RX TRAFFIC FAULTS
(Bottom line of disp'l
Rx Fault: Demod unlocked at <nn.nnnn>MHz
Rx Fault: FEC sync lost (demod locked)
Rx Fault: De-interleaver sync lost
Rx Fault: Frame sync lost
Rx Fault: TS32 Multiframe sync lost
P300H
Description / Cause / Notes
The FIFO which carries the CAS signalling from the Drop Mux to the Framer has slipped (full or
empty). This should never occur in operation (contact factory).
The FIFO which interfaces the Framer to the Reed-Solomon encoder has slipped (full or empty).
This should never occur in operation (contact factory).
Rx Traffic Faults: Rx OK LED Off and Rx Traffic (prompt) relay.
The Demod cannot find a carrier to lock to at the specified frequency. Check the frequency, check
the Data rate and FEC settings (use Info, View Config, Rx). Perhaps check the demod itself by
enabling a IF Loopback (Test, Loopback, IF).
The Demod can lock to the carrier, but the inner FEC decoder (Turbo, Vit or Seq) cannot lock to
the demodulated data. Check you have the correct FEC settings (ie Turbo, Vit or Seq as
appropriate, use Info, View Config, Rx). The most common other cause is Spectrum Inversion, you
can check this by temporarily turning on the Rx Spectrum Inversion (Change, Rx, Demod Spect
Inv).
The Demod can lock to the carrier, and the inner FEC decoder to the demodulated data. However
the Reed-Solomon De-interleaver cannot find sync with the decoded data. Check the RS de-
interleaving depth, then the values of `n` and `k`(use Info, View Config, Rx). On Non-Paradise Tx
modems, check the V.35 scrambler is not enabled in addition to the Reed-Solomon scrambler.
The modem cannot find the IBS or IDR frame sync on the receive data. Check the Rx Service
settings (Change, Rx, Service), although as the service type affects the composite data rate over
satellite, it is more likely the demod will fail to lock rather than this message appear if the wrong
service type is selected. On Non-Paradise Tx modems, for IBS, check the V.35 scrambler is not
enabled in addition to the IBS/SMS scrambler.
The modem cannot find the IBS TS32 Multiframe sync on the receive data although it has found
Frame sync (otherwise the message above would display). This is only likely in Custom IBS modes
where the operator has the option of sending a TS32 Multiframe or not. Note that for low data rates
the standard IBS/SMS multiframe period can be long (1 sec at 32kbps) and it may be best to use
Custom IBS without a TS32 MF for rates of below 32kbps to improve the acquisition time if the
carrier is momentarily lost.
P300 Series Installation and Operating Handbook
Relays To Terr To Sat Other
T TA,TC SB RF
T TA,TC SB RF
T TA,TC SB RF
T TA,TC SB RF
T TA,TC SB RF
Page 207