Promax TV EXPLORER HD ATSC Manual De Instrucciones página 67

USER'S MANUAL. TV EXPLORER
The BER measurement is provided in scientific notation (i.e. 1.8E-8 means
-8
1.8x10 , that is to say 1.8 average value of wrong bits of each 100,000,000) and through
a graphic bar (as its length is smaller the signal quality will be better). The analogue
representation is done on a logarithmic scale (not linear), that is to say, the bar divisions
correspond to the exponent of the measurement.
A signal is considered acceptable when SER-ERR/s ≥ 20 dB. This border is know
as TOV (Threshold Of Visibility) and it corresponds to an error rate after Viterbi of
3.0*10E-6 and a MER of 15 dB. This value is marked on the measurement bar of the
SER and therefore, SER for acceptable signals must be at the left side of this mark.
Figure 37.- Screen of SER measurement (8-VSB signals).
Finally it is shown a status line with information about the detected signal. The
possible messages that can appear and its meaning are showing the following list. The
messages are exposed from less to more fulfillment of the MPEG-2 standard:
No signal received
No signal has been detected.
Timing recovered
Only it is possible to recuperate the symbol time.
AFC in lock
The system automatic frequency control can identify and lock a digital
transmission (TDT) but its parameters can not be obtained. It can be due to a
transitory situation previous to the TPS identification (Transmission Parameter
Signaling) or well to a TDT transmission with an insufficient C/N ratio.
TPS in lock
The TPS (Transmission Parameter Signaling) are decoded. The TPS are carriers
containing information related to the transmission, modulation and codification:
Modulation type, Viterbi Code Rate, and Number of the received frame.
MPEG-2
Correct detection of a MPEG-2 signal.
12/2010
HD ATSC
Page 59