International Datacasting SuperFlex SFX2100 Series, Руководство пользователя

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RF Metrics Display Area
The RF Metrics Display Area presents an updated RF status of the DVB carrier being
currently received. This area remains displayed at all times and metrics information
presented here is only valid if the DVB Carrier A/B Lock Status indicates that the receiver is
locked to carrier A or B (green square). This display area is updated at the periodic refresh
rate set by the RF Metrics Refresh Rate (in seconds). The following metrics are displayed:
Metric Description
Signal Quality This display gives an indication of the Quality of the incoming
data stream. This feature is useful to evaluate the quality of the
incoming RF signal. A value from 0% to 100% is shown within
the display. The higher the percentage, the better the Carrier To
Noise (C/No) or quality of the digital carrier. This display is
based on an estimation of incoming noise by the receiver front
end and is accurate to
±
10
%
.
The display bar changes colour, according to the following:
Black – receiver is not locked to a carrier.
Red – signal quality is too low (1% to 24%).
Green – signal quality is in acceptable operating range (25% to
100%).
Signal Level This display provides a percentage of the signal strength of the
DVB carrier that is being received at the L-Band input to the
receiver.
The display bar changes colour, according to the following:
Black – receiver is not locked to a carrier.
Red – signal level is too low (1% to 19%) or too high (90% to
100%).
Yellow – signal level is marginally too low (20% to 29%) or
marginally too high (80% to 89%).
Green – signal level is in the acceptable AGC operating range
(30% to 80%).
LNB Offset This indicates what the current LNB offset is, based on the
automatic LNB drift tracking mechanism of the receiver. This
value is added or subtracted from the set frequency in the DVB
Carrier definition to tune to the carrier.
C/No This value represents the estimated carrier to noise ratio (in dB)
at the L-Band input to the receiver. The format of this value is
x.y dB.
Eb/No This value represents the calculated Eb/No (in dB) at the input
to the receiver. This value is derived from the C/No value, with
compensation for modulation scheme, reed-solomon FEC,
viterbi FEC rate, and symbol rate of the carrier.
Viterbi BER This is the number of bit errors encountered during a fixed frame
length of incoming data. This data is obtained from the receiver